SH 2 Reference Manual V1.2

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SH-2 Reference Manual
Document Number: 1000-3625
Document Revision: 1.2
Date: 05/19/2017

Hillcrest Laboratories, Inc. 15245 Shady Grove Road, Suite 400 Rockville, MD 20850
Copyright © 2017 Hillcrest Labs, Inc. All rights reserved.

Table of Contents
LIST OF FIGURES ............................................................................................................... 4
1.0
INTRODUCTION ....................................................................................................... 7
1.1
1.2
1.3

2.0
3.0

Intended Audience ................................................................................................................. 7
Scope ..................................................................................................................................... 7
Revision History ..................................................................................................................... 7

SENSOR USAGE ..................................................................................................... 8
HOST INTERFACES ............................................................................................... 10

3.1
UART Interface.....................................................................................................................10
3.1.1 S-format Output Packet ....................................................................................................10
3.1.2 L-format Output Packet ....................................................................................................10
3.1.3 H-format Output Packet....................................................................................................11

4.0

CONFIGURATION .................................................................................................. 13

4.1
Flash Storage .......................................................................................................................13
4.2
RAM Storage ........................................................................................................................13
4.3
Records ................................................................................................................................13
4.3.1 Static Calibration ..............................................................................................................13
4.3.2 Dynamic Calibration .........................................................................................................13
4.3.3 MotionEngine Power Management and Stability Classifier .............................................14
4.3.4 Sensor Orientation ...........................................................................................................14
4.3.5 AR/VR Stabilization ..........................................................................................................15
4.3.6 Significant Motion Detector Configuration ........................................................................16
4.3.7 Shake Detector Configuration ..........................................................................................16
4.3.8 Serial Number ..................................................................................................................17
4.3.9 Maximum Fusion Period ..................................................................................................17
4.3.10
Environmental Sensor Calibration .............................................................................17
4.3.11
Ambient Light Sensor (ALS) Calibration ....................................................................18
4.3.12
Proximity Sensor Calibration ......................................................................................18
4.3.13
Flip Detector Configuration ........................................................................................19
4.3.14
Pickup Detector Configuration ...................................................................................20
4.3.15
Stability Detector Configuration .................................................................................22
4.3.16
Activity Tracker Configuration ....................................................................................22
4.3.17
Sleep Detector Configuration .....................................................................................22
4.3.18
Tilt Detector Configuration .........................................................................................23
4.3.19
Pocket Detector Configuration ...................................................................................23
4.3.20
Circle Detector Configuration .....................................................................................24
4.3.21
User Record ...............................................................................................................25
4.3.22
MotionEngine Time Source Selection ........................................................................25
4.3.23
UART Output Format Selection .................................................................................25
4.3.24
Gyro-Integrated Rotation Vector ................................................................................25
4.3.25
Fusion Control Record ...............................................................................................27
4.3.26
Configuration Records Summary ...............................................................................27
4.3.27
Version Information ....................................................................................................28

5.0

OPERATION ........................................................................................................... 29

5.1
Sensor Metadata ..................................................................................................................29
5.1.1 Sensor-Specific Metadata ................................................................................................32

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5.2
Input Reports ........................................................................................................................32
5.3
Output Reports .....................................................................................................................33
5.4
Feature Reports ...................................................................................................................33
5.4.1 Rate Control .....................................................................................................................33
5.4.2 Threshold Control .............................................................................................................33
5.4.3 Batch Operation ...............................................................................................................33
5.5
Sensor Triggering .................................................................................................................34

6.0

REPORT DESCRIPTIONS ...................................................................................... 36

6.1
Report ID Convention ...........................................................................................................36
6.2
Summary ..............................................................................................................................36
6.3
Configuration Reports ..........................................................................................................37
6.3.1 Product ID Request (0xF9) ..............................................................................................37
6.3.2 Product ID Response (0xF8) ............................................................................................37
6.3.3 FRS Write Request (0xF7) ...............................................................................................38
6.3.4 FRS Write Data Request (0xF6) ......................................................................................38
6.3.5 FRS Write Response (0xF5) ............................................................................................39
6.3.6 FRS Read Request (0xF4) ...............................................................................................40
6.3.7 FRS Read Response (0xF3) ............................................................................................40
6.3.8 Command Request (0xF2) ...............................................................................................41
6.3.9 Command Response (0xF1) ............................................................................................41
6.4
Commands ...........................................................................................................................42
6.4.1 Report Errors (0x01).........................................................................................................43
6.4.2 Perform Self-Test .............................................................................................................44
6.4.3 Counter Commands (0x02) ..............................................................................................44
6.4.4 Tare (0x03) .......................................................................................................................45
6.4.5 Initialization (0x04) ...........................................................................................................47
6.4.6 Save DCD (0x06) .............................................................................................................49
6.4.7 ME Calibration Commands (0x07) ...................................................................................50
6.4.8 Configure Periodic DCD Save (0x09) ..............................................................................51
6.4.9 Get Oscillator Type (0x0A) ...............................................................................................52
6.4.10
Clear DCD and Reset (0x0B) .....................................................................................53
6.5
Sensor Reports ....................................................................................................................53
6.5.1 Common Fields ................................................................................................................54
6.5.2 Common Dynamic Feature Report ..................................................................................55
6.5.3 Get Feature Request (0xFE) ............................................................................................55
6.5.4 Set Feature Command (0xFD) .........................................................................................55
6.5.5 Get Feature Response (0xFC) .........................................................................................56
6.5.6 Force Sensor Flush (0xF0) ..............................................................................................56
6.5.7 Flush Completed (0xEF) ..................................................................................................57
6.5.8 Raw Accelerometer (0x14) ...............................................................................................57
6.5.9 Accelerometer (0x01) .......................................................................................................58
6.5.10
Linear Acceleration (0x04) .........................................................................................58
6.5.11
Gravity (0x06).............................................................................................................59
6.5.12
Raw Gyroscope (0x15) ..............................................................................................59
6.5.13
Gyroscope Calibrated (0x02) .....................................................................................60
6.5.14
Gyroscope Uncalibrated (0x07) .................................................................................60
6.5.15
Raw Magnetometer (0x16) ........................................................................................61
6.5.16
Magnetic Field Calibrated (0x03) ...............................................................................62
6.5.17
Magnetic Field Uncalibrated (0x0F) ...........................................................................62
6.5.18
Rotation Vector (0x05) ...............................................................................................63
6.5.19
Game Rotation Vector (0x08) ....................................................................................63
6.5.20
Geomagnetic Rotation Vector (0x09).........................................................................64
6.5.21
Pressure (0x0A) .........................................................................................................65
6.5.22
Ambient Light (0x0B) .................................................................................................65

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6.5.23
6.5.24
6.5.25
6.5.26
6.5.27
6.5.28
6.5.29
6.5.30
6.5.31
6.5.32
6.5.33
6.5.34
6.5.35
6.5.36
6.5.37
6.5.38
6.5.39
6.5.40
6.5.41
6.5.42
6.5.43
6.5.44

7.0

SH-2 Reference Manual

Humidity (0x0C) .........................................................................................................65
Proximity (0x0D).........................................................................................................66
Temperature (0x0E) ...................................................................................................66
Reserved (0x17).........................................................................................................67
Tap Detector (0x10) ...................................................................................................67
Step Detector (0x18) ..................................................................................................67
Step Counter (0x11) ...................................................................................................68
Significant Motion (0x12) ...........................................................................................69
Stability Classifier (0x13) ...........................................................................................69
Shake Detector (0x19) ...............................................................................................70
Flip Detector (0x1A) ...................................................................................................70
Pickup Detector (0x1B) ..............................................................................................71
Stability Detector (0x1C) ............................................................................................71
Personal Activity Classifier (0x1E) .............................................................................72
Sleep Detector (0x1F) ................................................................................................74
Tilt Detector (0x20) ....................................................................................................74
Pocket Detector (0x21) ..............................................................................................75
Circle Detector (0x22) ................................................................................................75
Heart Rate Monitor (0x23) .........................................................................................76
ARVR-Stabilized Rotation Vector (0x28) ...................................................................76
ARVR-Stabilized Game Rotation Vector (0x29) ........................................................77
Gyro-Integrated Rotation Vector (0x2A) ....................................................................77

BATCHING ............................................................................................................. 79

7.1
Batch queues .......................................................................................................................79
7.2
Batch timestamps .................................................................................................................79
7.2.1 Base Timestamp Reference (0xFB) .................................................................................79
7.2.2 Timestamp Rebase (0xFA) ..............................................................................................80

8.0
9.0

REFERENCES ........................................................................................................ 81
NOTICES ................................................................................................................ 82

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List of Figures
Figure 1: Document History .............................................................................................. 7
Figure 2: Sensor Usage ..................................................................................................... 9
Figure 3: S-format Output Packet Definition ................................................................... 10
Figure 4: L-format Output Packet Definition ................................................................... 11
Figure 5: H-format Output Packet Definition ................................................................... 12
Figure 6: MotionEngine Power Management and Stability Classifier Record ............. 14
Figure 7: Sensor Orientation Record .............................................................................. 14
Figure 8: AR/VR Stabilization Record ............................................................................. 15
Figure 9: Significant Motion Detector Configuration Record........................................ 16
Figure 10: Shake Detector Configuration Record .......................................................... 16
Figure 11: Serial Number Record.................................................................................... 17
Figure 12: Maximum Fusion Period Record ................................................................... 17
Figure 13: Environmental Sensor Calibration Record ................................................... 17
Figure 14: ALS Calibration Record ................................................................................. 18
Figure 15: Proximity Sensor Calibration Record ........................................................... 18
Figure 16: Flip Detector Configuration Record .............................................................. 19
Figure 17: Pickup Detector Configuration Record......................................................... 20
Figure 18: Stability Detector Configuration Record ...................................................... 22
Figure 19: Sleep Detector Configuration Record ........................................................... 22
Figure 20: Tilt Detector Configuration Record ............................................................... 23
Figure 21: Pocket Detector Configuration Record......................................................... 23
Figure 22: Circle Detector Configuration Record .......................................................... 24
Figure 23: User Record .................................................................................................... 25
Figure 24: Time Source Record ...................................................................................... 25
Figure 25: UART Output Format Selection Record ......................................................... 25
Figure 26: Gyro-Integrated Rotation Vector Configuration Record ............................... 26
Figure 27: Fusion Control Record .................................................................................. 27
Figure 28: Configuration Records .................................................................................. 28
Figure 29: Metadata Records .......................................................................................... 30
Figure 30: Metadata Record Format – Revision 3 .......................................................... 30
Figure 31: Metadata Record Format – Revision 4 .......................................................... 31
Figure 32: Personal Activity Classifier Sensor-Specific Metadata. .............................. 32
Figure 33: Sensor Trigger Modes ................................................................................... 35
Figure 34: Report ID List ................................................................................................. 37
Figure 35: Product ID Request ........................................................................................ 37
Figure 36: Product ID Response ..................................................................................... 38
Figure 37: FRS Write Request ......................................................................................... 38
Figure 38: FRS Write Data Request ................................................................................ 39
Figure 39: FRS Write Response ...................................................................................... 39
Figure 40: FRS Read Request ......................................................................................... 40
Figure 41: FRS Read Response ...................................................................................... 40
Figure 42: Command Request ........................................................................................ 41
Figure 43: Command Response...................................................................................... 42
Figure 44: Command Identifiers...................................................................................... 43
Figure 45: Report Errors Command................................................................................ 43
Figure 46: Report Errors Response ................................................................................ 44
Figure 47: Get Counts Command ................................................................................... 44
Figure 48: Get Counts Response .................................................................................... 45

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Figure 49: Clear Counts Command ................................................................................ 45
Figure 50: Tare Now Command....................................................................................... 46
Figure 51: Persist Tare Command .................................................................................. 47
Figure 52: Set Reorientation Command ......................................................................... 47
Figure 53: Initialize Command......................................................................................... 48
Figure 54: Initialize Command Subsystems ................................................................... 48
Figure 55: Initialize Response ......................................................................................... 48
Figure 56: Save DCD Command...................................................................................... 49
Figure 57: Save DCD Response ...................................................................................... 49
Figure 58: Configure ME Calibration Command ............................................................ 50
Figure 59: Get ME Calibration Command ....................................................................... 50
Figure 60: Configure ME Calibration Response............................................................. 51
Figure 61: Configure Periodic Save DCD Command ..................................................... 52
Figure 62: Get Oscillator Type Command ....................................................................... 52
Figure 63: Get Oscillator Type Response ...................................................................... 53
Figure 64: Clear DCD and Reset Command .................................................................... 53
Figure 65: Common Report Fields .................................................................................. 54
Figure 66: Common Feature Report ............................................................................... 55
Figure 67: Get Feature Request (0xFE) .......................................................................... 55
Figure 68: Set Feature Command (0xFD) ....................................................................... 56
Figure 69: Get Feature Response (0xFC) ....................................................................... 56
Figure 70: Force Sensor Flush (0xF0) ............................................................................ 57
Figure 71: Flush Completed (0xEF) ................................................................................ 57
Figure 72: Raw Accelerometer Input Report .................................................................. 57
Figure 73: Accelerometer Input Report .......................................................................... 58
Figure 74: Linear Acceleration Input Report .................................................................. 58
Figure 75: Gravity Input Report....................................................................................... 59
Figure 76: Raw Gyroscope Input Report ........................................................................ 60
Figure 77: Gyroscope Calibrated Input Report .............................................................. 60
Figure 78: Gyroscope Uncalibrated Input Report .......................................................... 61
Figure 79: Raw Magnetometer Input Report .................................................................. 61
Figure 80: Magnetic Field Calibrated Input Report ........................................................ 62
Figure 81: Magnetic Field Uncalibrated Input Report .................................................... 63
Figure 82: Rotation Vector Input Report ........................................................................ 63
Figure 83: Game Rotation Vector Input Report .............................................................. 64
Figure 84: Geomagnetic Rotation Vector Input Report ................................................. 64
Figure 85: Pressure Sensor Input Report ....................................................................... 65
Figure 86: Ambient Light Sensor Input Report .............................................................. 65
Figure 87: Humidity Sensor Input Report ....................................................................... 66
Figure 88: Proximity Sensor Input Report ...................................................................... 66
Figure 89: Temperature Sensor Input Report ................................................................ 66
Figure 90: Tap Detector Input Report ............................................................................. 67
Figure 91: Step Detector Input Report ............................................................................ 68
Figure 92: Step Counter Input Report............................................................................. 68
Figure 93: Significant Motion Input Report .................................................................... 69
Figure 94: Stability Classifier Input Report .................................................................... 69
Figure 95: Shake Detector Input Report ......................................................................... 70
Figure 96: Flip Detector Input Report ............................................................................. 71
Figure 97: Pickup Detector Input Report ........................................................................ 71
Figure 98: Stability Detector Input Report ...................................................................... 72
Figure 99: Personal Activity Classifier Feature Report. ................................................ 72

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Figure 100:
Figure 101:
Figure 102:
Figure 103:
Figure 104:
Figure 105:
Figure 106:
Figure 107:
Figure 108:
Figure 109:
Figure 110:
Figure 111:
Figure 112:

SH-2 Reference Manual

Personal Activity Classifier Report ............................................................. 73
Activity Classification States ...................................................................... 74
Sleep Detector Input Report ........................................................................ 74
Tilt Detector Input Report ............................................................................ 74
Pocket Detector Input Report ...................................................................... 75
Circle Detector Input Report ........................................................................ 75
Heart Rate Monitor Input Report ................................................................. 76
ARVR-Stabilized Rotation Vector Input Report .......................................... 77
ARVR-Stabilized Game Rotation Vector Input Report ............................... 77
Gyro-Integrated Rotation Vector Input Report ........................................... 78
Timestamp Dependencies ........................................................................... 79
Base Timestamp Reference Record ........................................................... 80
Timestamp Rebase Record ......................................................................... 80

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1.0

SH-2 Reference Manual

Introduction

The SH-2 is Hillcrest’s turnkey sensor hub software solution. The SH-2 connects to various
motion and environmental sensors, collects data from them, processes that data and provides
the results to a host processor.

1.1

Intended Audience

This document is intended for application developers implementing products that use the SH-2.

1.2

Scope

This document describes the features of the SH-2, how they work, how to use them and the
application programming interface (API) for the SH-2. This document assumes the reader is
already familiar with Hillcrest’s MotionEngine.

1.3

Revision History

1.2

Revision

Date
05/19/2017

1.1

02/16/2017

1.0

02/06/2017

Description
Clarified Tare command usage, added description of Tare
application to AR/VR Stabilized Rotation Vectors and GyroIntegrated Rotation Vector. Clarified FRS Read “BUSY” status
behavior. Fix bad references. Added language clarifying
interaction between Gyro-Integrated Rotation Vector and other
fusion outputs. Clarified SHTP channels in 6.2.
Update the default value of AR/VR Stabilization FRS record.
Remove unused reference.
Initial issue

Figure 1: Document History

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SH-2 Reference Manual

Sensor Usage

The SH-2 connects to and manages a variety of physical sensors. It processes the outputs of
the physical sensors to produce virtual sensors. Virtual sensors require data from one or more
physical sensors. Figure 2 indicates which physical sensors are required for which virtual
sensors. The number of physical sensors in use at any one time impacts the power consumed
by the device. Using more physical sensors means consuming more power.

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HRM

temperature

proximity

humidity

ambient light

pressure

magnetometer

gyroscope

Virtual Sensors
Raw accelerometer
Acceleration
Linear acceleration
Gravity
Raw gyroscope
Gyroscope calibrated
Gyroscope uncalibrated
Raw magnetometer
Magnetic field calibrated
Magnetic field uncalibrated
Rotation vector
Game rotation vector
Geomagnetic rotation vector
Pressure
Ambient light
Humidity
Proximity
Temperature
Tap detector
Step detector
Step counter
Significant motion
Stability classifier
Shake detector
Flip detector
Pickup detector
Stability detector
Personal Activity classifier
Sleep detector
Tilt detector
Pocket detector
Circle detector
Heart rate monitor
AR/VR Stabilized Rotation
Vector
AR/VR Stabilized Game
Rotation Vector
Gyro-Integrated Rotation
Vector

accelerometer

Physical Sensors

X
X
X
X
X
X
X
X
X
X
X
X

X
X
X

X
X

X
X
X
X
X
X
X
X
X

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

X

X

X
X

X

X

X

X

X

X

X1

Figure 2: Sensor Usage
1

Magnetometer is not required when Gyro-Integrated Rotation Vector is configured with the Game
Rotation Vector as its Reference Data Type (see 4.3.24).
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3.0

SH-2 Reference Manual

Host Interfaces

The SH-2 communicates to the host processor through Hillcrest’s Sensor Hub Transport
Protocol. See [1] for details of the SHTP protocol. See [2] for details of how SH-2 uses SHTP.

3.1

UART Interface

Certain SH-2 products support a UART interface with special output formats. There are two
such output formats available.

3.1.1 S-format Output Packet
The S-format is the default output packet format for the UART mode. This output packet
provides heading information. Below is a description of the output packet layout:
Byte
0
1
2
3
4
5

Description
Header = 0xAA
Reserved = 0x00
Sequence Number
Angle LSB
Angle MSB
Checksum

Figure 3: S-format Output Packet Definition

Header

Packet header byte, always equal to 0xAA.

Reserved

Reserved byte, always equal to 0x00.

Sequence Number

Sequence number of the packet. The first packet sent after
startup will have a sequence number of 0. After the 256th packet
is sent the sequence number rolls over back to 0.

Angle

16-bit heading value expressed in units of centidegrees (degrees
x100). This value has a range of -18000 to 18000 centidegrees.

Checksum

Checksum of the packet, equal to the XOR of the sequence
number and angle bytes of the packet.

3.1.2 L-format Output Packet
The L-format packet is an alternate output packet format for the UART mode. This output packet
format needs to be selected using an FRS record – see 4.3.23 for more information on the FRS
record. Below is a description of the output packet layout.
Byte
0
1
2
3
4
5
6
7
8

Description
Header LSB = 0xAC
Header MSB = 0xAC
Sequence Number
Angle LSB
Angle MSB
Angular velocity LSB
Angular velocity MSB
X-axis acceleration LSB
X-axis acceleration MSB

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Byte
9
10
11
12
13
14

Description
Y-axis acceleration LSB
Y-axis acceleration MSB
Z-axis acceleration LSB
Z-axis acceleration MSB
Reserved
Checksum

Figure 4: L-format Output Packet Definition

Header

16-bit packet header, always equal to 0xACAC.

Sequence Number

Sequence number of the packet. The first packet sent after
startup will have a sequence number of 0. After the 256th packet
is sent the sequence number rolls over back to 0.

Angle

16-bit heading value expressed in units of decidegrees (degrees
x10). This value has a range of -1800 to 1800 decidegrees.

Angular velocity

16-bit angular velocity value expressed in units of decidegrees
per second (degrees per second x10).

X-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
X-direction.

Y-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
Y-direction.

Z-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
Z-direction.

Reserved

Reserved byte, always equal to 0x00.

Checksum

Checksum of the packet, equal to the sum of the sequence
number, angle, angular velocity, and acceleration bytes of the
packet.

3.1.3 H-format Output Packet
The H-format packet is another alternate output packet format for the UART mode. This output
packet provides Euler angles and acceleration values. This output packet format needs to be
selected using an FRS record – see 4.3.23 for more information on the FRS record. Below is a
description of the output packet layout.
Byte
0
1
2
3
4
5

Description
Header LSB = 0xAA
Header MSB = 0xAA
Sequence Number
Yaw LSB
Yaw MSB
Pitch LSB

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Byte
6
7
8
9
10
11
12
13
14
15
16
17
18

Description
Pitch MSB
Roll LSB
Roll MSB
X-axis acceleration LSB
X-axis acceleration MSB
Y-axis acceleration LSB
Y-axis acceleration MSB
Z-axis acceleration LSB
Z-axis acceleration MSB
Reserved
Reserved
Reserved
Checksum

Figure 5: H-format Output Packet Definition

Header

16-bit packet header, always equal to 0xAAAA.

Sequence Number

Sequence number of the packet. The first packet sent after
startup will have a sequence number of 0. After the 256th packet
is sent the sequence number rolls over back to 0.

Yaw

16-bit angular yaw value expressed in units of centidegrees
(degrees x100).

Pitch

16-bit angular pitch value expressed in units of centidegrees
(degrees x100).

Roll

16-bit angular roll value expressed in units of centidegrees
(degrees x100).

X-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
X-direction.

Y-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
Y-direction.

Z-axis acceleration

16-bit acceleration value expressed in milli-gravities (gravitational
constant x1000) representing the acceleration of the device in the
Z-direction.

Reserved

Reserved bytes, always equal to 0x00.

Checksum

Checksum of the packet, equal to the sum of the sequence
number, yaw, pitch, roll, acceleration and reserved bytes of the
packet.

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4.0

SH-2 Reference Manual

Configuration

The SH-2 has a number of configurable options that control the overall behavior of the hub.
These configuration options are stored as records in either flash or RAM. Only one record of
each configuration options may be stored. Access to the configuration records is provided
through reports described in section 6.3.

4.1

Flash Storage

The SH-2 can be implemented on processors with flash memory. On these systems the
configuration records persist through power cycles. The configuration options may be changed
at any time; however, the SH-2 must be restarted for changes to take effect. The SH-2 has a
very simple flash record system (FRS) that manages reading, writing and erasing these records.
The FRS implements wear leveling to reduce wear on the flash memory.

4.2

RAM Storage

The SH-2 can also be implemented on processors without flash. In these systems the
configuration records are stored in RAM. They must be downloaded each time the SH-2 is
started. To change configuration options, restart the SH-2 and download new options.

4.3

Records

4.3.1 Static Calibration
Static calibration data is produced by the manufacturing process for per device calibration and
stored on the SH-2. There are two per device calibration records – one for the accelerometer,
gyroscope and magnetometer (AGM) sensor set and one for the screen rotation accelerometer
(SRA). The SH-2 uses a nominal calibration if static calibration data is not configured. The
nominal calibration is built-in to the SH-2 sensor drivers. There are two nominal calibration
records – one for the AGM sensor set and one for the SRA. The per device records are
read/write. The nominal records are read only. The data format is proprietary to Hillcrest Labs.

4.3.2 Dynamic Calibration
Dynamic calibration is produced by MotionEngine during operation. Dynamic calibration may be
stored for use following a restart to enhance MotionEngine’s startup performance. The data
format is proprietary to Hillcrest Labs.

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4.3.3 MotionEngine Power Management and Stability Classifier
The MotionEngine power management record controls the thresholds MotionEngine uses to
determine when the device is at rest and when it is in motion. The format of a MotionEngine
Power Management record is shown in Figure 6. This record also configures the thresholds use
by the stability classifier.
Description
Word
0
1
2

Byte 3

Reserved

Byte 2
Byte 1
Byte 0
Delta orientation
Stable threshold
Delta acceleration
Stable duration

Figure 6: MotionEngine Power Management and Stability Classifier Record

Delta orientation

Once a device has been determined to be not moving based
on the generation of ON_TABLE or IS_STABLE, delta
orientation is the amount of change in device orientation
required to recognize that the device is in motion. The units
are radians. The delta orientation value is a signed, 2’scomplement fixed point number with a Q point of 28. The
default value is 0.2.

Stable threshold

The gyro output must be below this limit for the stable duration
in order for an IS_STABLE notification to be generated. The
units are radians per second. The stable threshold value is a
signed, 2’s-complement fixed point number with a Q point of
25. The default value is 1.0.

Stable duration

The amount of time in seconds that motion must be below the
stable threshold before an IS_STABLE notification is
generated. The default value is 3.

Delta acceleration

When using wake-on-motion, this is the amount of
acceleration required for the accelerometer to determine that
motion has occurred. The units are mg. The delta acceleration
value is unsigned. The default value is 0.

4.3.4 Sensor Orientation
The sensor orientation record controls the rotation of the MotionEngine output coordinate
system relative to the sensor’s coordinate system. The rotation vector is a signed, 2’scomplement fixed point number with a Q point of 30. The format of a sensor orientation record is
shown in Figure 7. If the rotation vector is set to all 0’s then no rotation is applied. The default
values are 0 for all for values. In addition, each accelerometer, gyroscope and magnetometer
has its own sensor orientation record. The sensor specific records are used to align the
orientation of sensors to the system when not using per device static calibration data.
Word
0
1
2
3

Description
Rotation quaternion X
Rotation quaternion Y
Rotation quaternion Z
Rotation quaternion W

Figure 7: Sensor Orientation Record

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4.3.5 AR/VR Stabilization
During large, fast motions the angular position output may sometimes become misaligned with
the actual angular position. When the device slows or stops, angular position can be determined
accurately and the angular position output updated accordingly. However, step updates to the
output are undesirable in some applications. AR/VR stabilization addresses this issue by
correcting angular position errors only when the device is moving.
The AR/VR stabilization record controls the thresholds MotionEngine uses to stabilize angular
position. The format of an AR/VR stabilization record is shown in Figure 8. The AR/VR
stabilization parameters are all unsigned, fixed point numbers. There are separate AR/VR
stabilization records for the rotation vector and game rotation vector. If a record is not
programmed then default values of 0 are used for all parameters.
Word
0
1
2
3

Description
Scaling
Max rotation
Max error
Stability magnitude

Figure 8: AR/VR Stabilization Record

Scaling

Scaling controls what fraction of the angular velocity can be
used to correct angular position errors. The range for this
parameter is 0 to 1.0. This parameter is dimensionless. The Q
point is 30. A typical value is 0.2.

Max rotation

Max rotation is the maximum amount of angular correction
that can be used to correct angular position errors. The
settings for scaling and max rotation determine how
aggressively angular errors are corrected. The range is 0 to
PI. The units are radians. The Q point is 29. A typical value is
7.3 degrees or 0.127 radians.

Max error

Max error is the maximum angular error allowed to
accumulate before the angular position output is updated in a
single step. The units are radians. The range is 0 to PI. The Q
point is 29. A typical value is 45 degrees or 0.785 radians.

Stability magnitude

Stability magnitude controls the amount of change in angular
position that must occur before the angular position output is
updated with a new value. The units are radians. The Q point
is 29. A typical value is 0.0 degrees or 0.0 radians.

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4.3.6 Significant Motion Detector Configuration
The significant motion detector has several parameters that must be configured. The
configuration parameters are 32-bit integers or 32-bit signed fixed point numbers. If this record
is not programmed then default values are used.
Word
0
1

Description
Acceleration threshold
Step threshold

Figure 9: Significant Motion Detector Configuration Record

Acceleration threshold

The acceleration threshold to trigger significant motion. The
default value is 10.0 m/s^2. The Q point is 24.

Step threshold

The number of steps required to trigger significant motion. The
default value is 5. This is an unsigned integer.

4.3.7 Shake Detector Configuration
The shake detector has several parameters that must be configured. The configuration
parameters are 32-bit signed integers, 32-bit signed fixed point numbers or bit fields. If this
record is not programmed then default values are used.
Word
0
1
2
3
4

Description
Minimum time
Maximum time
Threshold
Shake count
Enable flags

Figure 10: Shake Detector Configuration Record

Minimum time

The minimum time in microseconds between direction
changes. The default value is 50,000us.

Maximum time

The maximum time in microseconds between direction
changes. The default value is 400,000us.

Threshold

The threshold in m/s^2 that must be exceeded to count as a
direction change. The default value is 8.0m/s^2. The Q point is
26.

Shake count

The number of direction changes to count as a shake. The
default value is 3.

Enable flags

Enable flags for shake detection on the X, Y and Z axes. 0 –
disable, 1 – enable. X, Y, and Z axes are enabled by default.
Bit 0 – X axis
Bit 1 – Y axis
Bit 2 – Z axis
Bit 3:7 - reserved

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4.3.8 Serial Number
The serial number record stores a 32-bit number used to identify an individual device. The
format of a serial number record is shown in Figure 11.
Word
0

Description
32-bit serial number

Figure 11: Serial Number Record

4.3.9 Maximum Fusion Period
The maximum fusion period record stores the maximum fusion period allowed. The units are
microseconds. If a fusion period larger than this maximum is requested then the fusion period
will be set to this maximum. The fusion period check can be disabled by clearing this record or
by setting the maximum to 0.
Word
0

Description
Max fusion period

Figure 12: Maximum Fusion Period Record

4.3.10

Environmental Sensor Calibration

Each environmental sensor may require calibration. The calibration parameters for the
environmental sensors are offset and scale. Offset accounts for a fixed difference between the
output of the sensor and the actual value. Scale accounts for the difference between how much
the output of the sensor changes and how much the actual value changes. Offset and scale are
both signed fixed point numbers. The Q point is different for each type of sensor. If the
calibration record for a particular sensor is not programmed then default values of offset = 0 and
scale = 1 are used.
Word
0
1

Description
Offset
Scale

Figure 13: Environmental Sensor Calibration Record

Offset

The offset value is added to the output of the sensor. The Q
points are:
Pressure:
20
Temperature: 7
Humidity:
8
Ambient Light: 8
Proximity:
4

Scale

The output of the sensor is multiplied by the scale. The Q
points are:
Pressure:
15
Temperature: 15
Humidity:
15
Ambient Light: 15
Proximity:
15

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SH-2 Reference Manual

Ambient Light Sensor (ALS) Calibration

The ALS may require additional calibration parameters beyond the simple scale and offset
provided to all environmental sensors. These parameters are device specific and are stored in
the ALS Calibration Record.
Word
0
1
1..N

Description
Sensor GUID
Bits 7:0 – Length
Bits 31:8 - Reserved
Parameters

Figure 14: ALS Calibration Record

Sensor GUID

An ID that uniquely identifies the sensor for which the
calibration record was created.

Length

Length in words of the parameters section of the record.

Parameters

The calibration parameters applicable for a specific sensor.
Contact Hillcrest Labs for details.

4.3.12

Proximity Sensor Calibration

The proximity sensor may require additional calibration parameters beyond the simple scale and
offset provided to all environmental sensors. These parameters are device specific and are
stored in the Proximity Sensor Calibration Record.
Word
0
1
1..N

Description
Sensor GUID
Bits 7:0 – Length
Bits 31:8 - Reserved
Parameters

Figure 15: Proximity Sensor Calibration Record

Sensor GUID

An ID that uniquely identifies the sensor for which the
calibration record was created.

Length

Length in words of the parameters section of the record.

Parameters

The calibration parameters applicable for a specific sensor.
Contact Hillcrest Labs for details.

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SH-2 Reference Manual

Flip Detector Configuration

The flip detector has several parameters that must be configured. The configuration parameters
are 32-bit signed fixed point numbers. If this record is not programmed then default values are
used.
Word
0
1
2

Description
Time constant
Angular threshold
Angular hysteresis

Figure 16: Flip Detector Configuration Record

Time constant

The time constant used for filtering input data. The default
value is 0.4. The Q point is 20.

Angular threshold

The angle in radians, measured from a downward pointing line
(i.e. line pointing toward earth) defining the maximum range to
be in the down state. The default value is pi/4 (45 degrees).
The Q point is 29.

Angular hysteresis

The angle in radians defining the amount of hysteresis to
apply. The hysteresis region is angular threshold ± (angular
hysteresis / 2). The default value is pi/90 (2 degrees). The Q
point is 29.

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4.3.14

SH-2 Reference Manual

Pickup Detector Configuration

The pickup detector has several parameters that must be configured. The configuration
parameters are 32-bit signed fixed point numbers. If this record is not programmed then default
values are used.
The pickup detector can be operated in three different modes. The first mode, “Level-to-notlevel” (LNL) reports a pick-up event when the sensor hub moves from a level position to a nonlevel position. The second mode, “Stopped within Tilt Region” (SWTR) reports a pick-up event
when the sensor hub is rotated to a given angular position and held there. The third mode
reports a pick-up event when either the LNL or SWTR conditions are satisfied.
These detectors are configured independently. In Figure 17, fields are identified as belonging to
the “Level-to-Not-Level” (LNL) detector or the “Stopped Within Tilt Region” (SWTR) detector.
Description
Word
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

MSB

LSB
Enabled detectors
LNL Orientation Y
LNL Orientation X
LNL Orientation W
LNL Orientation Z
LNL Group Delay
LNL Angular Deviation
LNL Angular Hysteresis
SWTR Orientation Y
SWTR Orientation X
SWTR Orientation W
SWTR Orientation Z
SWTR Group Delay
SWTR Roll Minimum
SWTR Roll Maximum
SWTR Pitch Minimum
SWTR Pitch Maximum
SWTR Stable Acceleration
SWTR Motion Acceleration
SWTR Motion to Stable Duration

Figure 17: Pickup Detector Configuration Record

Enabled Detectors

A bitmap of enabled detectors. LNL and SWTR detectors are
enabled by default.
Bit 0 – LNL detector
Bit 1 – SWTR detector
Bit 2:31 – reserved

LNL Orientation

A rotation quaternion that is applied to the input before
computing what is "level". The default value is the identity
quaternion. The Q point is 14.

LNL Group delay

The desired group delay in seconds. The default value is 0.4
seconds. The Q point is 20.

LNL Angular Deviation

The angle (in radians) defining much tilt there can be and still
consider the device "level". The default value is pi/4 radians
(45 degrees). The Q point is 29.

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LNL Angular Hysteresis

The angle (in radians) defining the amount of hysteresis to
apply. The entry point for level will be: angDeviation angHysteresis/2. The exit point from level will be:
angDeviation + angHysteresis/2. The default value is pi/90
radians (2 degrees). The Q point is 29.

SWTR Orientation

A rotation quaternion that is applied to the input before
decomposing into roll and pitch. The default value is (0.7071,
0, 0, 0.7071) for (W,X,Y,Z). The Q point is 14.

SWTR Group Delay

The desired group delay in seconds. The default value is
0.125 seconds. The Q point is 20.

SWTR Roll Minimum

The minimum roll value (in rads) when stopped to trigger a
detection. The default value is –pi/18 radians (-10 degrees).
The Q point is 29.

SWTR Roll Maximum

The maximum roll value (in rads) when stopped to trigger a
detection. The default value is 2.96706 radians (170 degrees).
The Q point is 29.

SWTR Pitch Minimum

The minimum pitch value (in rads) when stopped to trigger a
detection. The default value is –pi/3 radians (-60 degrees).
The Q point is 29.

SWTR Pitch Maximum

The maximum pitch value (in rads) when stopped to trigger a
detection. The default value is pi/3 radians (60 degrees). The
Q point is 29.

SWTR Stable Acceleration

The largest acceleration (in m/s^2) that is allowed to indicated
stopped. The default value is 1.0 m/s^2. The Q point is 24.

SWTR Motion Acceleration

The smallest acceleration (in m/s^2) that will trigger motion.
The default value is 4.0 m/s^2. The Q point is 24.

SWTR Motion to Stable
Duration

The amount of time allowed (in seconds) between the last
detected motion and when the device is stopped. The Q point
is 20. The default value is 1.0 seconds.

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SH-2 Reference Manual

Stability Detector Configuration

The stability detector has several parameters that must be configured. The configuration
parameters are 32-bit fixed point numbers. If this record is not programmed then default values
are used.
Word
0
1

Description
Acceleration threshold
Duration

Figure 18: Stability Detector Configuration Record

Acceleration threshold

The acceleration in m/s^2 that must be exceeded to trigger not
stable. The default value is 0.784 m/s^2. The Q point is 24.
This value is signed.

Duration

The duration in microseconds that acceleration must remain
below the acceleration threshold in order to declare that the
device is stable. The default value is 500,000us. The Q point
is 0. This value is unsigned.

4.3.16

Activity Tracker Configuration

The data format of the Activity Tracker Configuration is proprietary to Hillcrest Labs.

4.3.17

Sleep Detector Configuration

The sleep detector has several parameters that must be configured. The configuration
parameters are 32-bit unsigned fixed point numbers. If this record is not programmed then
default values are used.
Word
0
1
2
3

Description
Filter coefficient
Processing window
Categorization window
Calibration constant

Figure 19: Sleep Detector Configuration Record

Filter coefficient

A coefficient used to clamp low acceleration values to 0. The
default value is 0.035. The Q point is 29.

Processing window

The processing window size in seconds. The default value is
10. The Q point is 0.

Categorization window

The categorization window size in number of processing
windows. The default value is 6. The Q point is 0.

Calibration constant

A unitless calibration constant that tunes how small a
movement triggers a hard wake. It should be tuned
experimentally. The default value is 0.45. The Q point is 29.

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SH-2 Reference Manual

Tilt Detector Configuration

The tilt detector has several parameters that must be configured. The configuration parameters
are 32-bit signed fixed point numbers. If this record is not programmed then default values are
used.
Word
0
1

Description
Processing window
Angular threshold

Figure 20: Tilt Detector Configuration Record

Processing window

The processing window size in seconds. The default value is
2. The Q point is 27.

Angular threshold

The cosine of the angle that defines a tilt. The default value is
cos(35 degrees) = 0.81915… The Q point is 30.

4.3.19

Pocket Detector Configuration

The pocket detector has several parameters that must be configured. The configuration
parameters are 32-bit signed fixed point numbers. If this record is not programmed then default
values are used.
Word
0
1
2
3
4
5
6
7
8
9
10
11
12

Description
MSB
LSB
Orientation Y
Orientation X
Orientation W
Orientation Z
Orientation Group Delay
Angular Ghost Group Delay
Near threshold
Dark threshold
Level threshold
Inverted threshold
Straight threshold
Linear motion threshold
Angular motion threshold
Motion timeout
Opaque adjacency debounce time

Figure 21: Pocket Detector Configuration Record

Orientation

A rotation quaternion that is applied to the input before pocket
determination. The default value is the identity quaternion.
The Q point is 14.

Orientation Group Delay

The desired group delay of the orientation filter in seconds.
The Q point is 20.

Angular Ghost Group
Delay

The desired group delay of the angular ghost filter in seconds.
The Q point is 20.

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Near Threshold

The threshold below which values are considered near. The
default value is 3 cm. The Q point is 0.

Dark Threshold

The threshold below which values are considered dark. The
default value is 10 lux. The Q point is 0.

Level Threshold

The threshold at which a “level” state is determined. The
default value is cos(15 degrees). The Q point is 29.

Inverted Threshold

The threshold at which a “inverted” state is determined. The
default value is cos(100 degrees). The Q point is 29.

Straight Threshold

The threshold at which a “straight” state is determined The
default value is sin(10 degrees). The Q point is 29.

Linear Motion Threshold

The threshold at which linear motion is considered. The
default value is 2 m/s^2. The Q point is 26.

Angular Motion Threshold

The threshold at which angular motion is considered. The
default value is pi/3 rad/s. The Q point is 28.

Motion Timeout

The timeout for determining motion consideration. The default
value is 1 second. The Q point is 20.

Opaque Adjacency
Debounce Time

The debounce time for determining opaque adjacency (a near
and dark state). The default value is 1 second. The Q point is
20.

4.3.20

Circle Detector Configuration

The circle detector has several parameters that must be configured. The configuration
parameters are 32-bit signed fixed point numbers. If this record is not programmed then default
values are used.
Word
0
1
2

Description
Acceleration threshold
Angular threshold
Revolution threshold

Figure 22: Circle Detector Configuration Record

Acceleration threshold

The threshold of acceleration change from gravity to be
considered circle motion. The default value is 4 m/s^2. The Q
point is 24.

Angular threshold

The threshold of angle between rotation axes. The default
value is 0. The Q point is 30.

Revolution threshold

The threshold for revolutions in radians. The default value is
3pi. The Q point is 25.

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4.3.21

SH-2 Reference Manual

User Record

There is a record available for the user to store data. The data must be stored as words. The
user record should be limited to 64 words.
Word
0
…
n

Description
User defined

Figure 23: User Record

4.3.22

MotionEngine Time Source Selection

MotionEngine needs to know how to determine the amount of time between two samples from
gyroscope. There are two methods for determining the sample time. The first method is to use
the period that the gyroscope is set to. The second method is to use the sample timestamps
provided by the system clock from the chip on which the sensor hub library is operating. If the
system clock is based on a crystal or an accurate oscillator (±2%) then use time stamps;
otherwise use the gyroscope period.
Word
0

Description
Time source

Figure 24: Time Source Record

0 – use gyroscope period
1 – use timestamps
others – reserved

Time source

4.3.23

UART Output Format Selection

Some SH-2 products support UART output. There are multiple output formats available for
products operating in UART mode. This FRS record is used to select which output format to
use. If this record is not present in a system, the S-format output is used by default.
Word
0

Description
UART Output Format Selection

Figure 25: UART Output Format Selection Record

0 – S-format Output

UART Output Format
Selection

1 – L-format Output
2 – H-format Output
others – reserved

4.3.24

Gyro-Integrated Rotation Vector

The Gyro-Integrated Rotation Vector provides high-rate, low-latency rotation vector output. It
can be configured to use several different sources as a reference vector, and prediction can
optionally be enabled and tuned.
Description
Word
0
1

MSB
LSB
Reserved
Reference Data Type
Synchronization Interval

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Description
Word
2
3
4
5
6

MSB

LSB
Maximum Error
Prediction Amount
Alpha
Beta
Gamma

Figure 26: Gyro-Integrated Rotation Vector Configuration Record

Reference Data Type

The slower fused result which is used to provide periodic
corrections to the fast gyro integration process. Acceptable
values are 0x0207 (6-axis Game Rotation Vector) and 0x0204
(9-axis Absolute Rotation Vector). Default value is 6-axis
Game Rotation Vector (0x0207).

Reserved

Set to 0.

Synchronization Interval

Duration, in microseconds, desired between outputs of
reference data type. The units are microseconds. The default
value is 10000 (equivalent to 100 Hz).

Maximum Error

Maximum discrepancy, in radians, between the gyrointegrated rotation vector and the reference vector that can be
used for smooth corrections. If the reference vector diverges
from the gyro-integrated rotation vector by more than this
amount, the gyro-integrated rotation vector will be updated in
a single discontinuous step to match the reference.
The units are radians. The Q-point is 29. The default value is
π/6 (equivalent to 30 degrees).

Prediction amount

Amount forward in time at which prediction will be performed.
The units are seconds. The Q-point is 10. Default value is 0.
Set this to 0 to disable prediction.

Alpha

Unitless position prediction parameter. The Q-point is 20.
Default value is 0.303072543909142

Beta

Unitless velocity prediction parameter. The Q-point is 20.
Default value is 0.113295896384921

Gamma

Unitless acceleration prediction parameter. The Q-point is 20.
Default value is 0.002776219713054

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4.3.25

SH-2 Reference Manual

Fusion Control Record

MotionEngine needs to know if the Game Rotation Vector is to use the magnetometer for
stabilization. This is a bit oriented flag word.
Word
0

Description
Flags

Figure 27: Fusion Control Record

Bit 0 - Enable Mag
Stabilized Game Rotation
Vector

0 – False
1 – True
others – reserved

4.3.26

Configuration Records Summary

A list of all the configuration records is shown in Figure 28.

Record ID
0x7979
0x4D4D
0x8A8A
0x4E4E
0x1F1F
0xD3E2
0x2D3E
0x2D41
0x2D43
0x2D46
0x2D4C
0x3E2D
0x3E2E
0xC274
0x7D7D
0xD7D7
0x4B4B
0x39AF
0x4D20
0x1AC9
0x39B1
0x4DA2
0xD401
0xD402
0x1B2A
0xFC94
0xED85
0xED88
0xED87
0xED89

Description
Static calibration – AGM
Nominal calibration – AGM
Static calibration – SRA
Nominal calibration - SRA
Dynamic calibration
MotionEngine power management
System orientation
Primary accelerometer orientation
Screen rotation accelerometer orientation
Gyroscope orientation
Magnetometer orientation
AR/VR stabilization – rotation vector
AR/VR stabilization – game rotation vector
Significant Motion detector configuration
Shake detector configuration
Maximum fusion period
Serial number
Environmental sensor - Pressure calibration
Environmental sensor - Temperature calibration
Environmental sensor - Humidity calibration
Environmental sensor - Ambient light calibration
Environmental sensor - Proximity calibration
ALS Calibration
Proximity Sensor Calibration
Pickup detector configuration
Flip detector configuration
Stability detector configuration
Activity Tracker configuration
Sleep detector configuration
Tilt detector configuration

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Record ID
0xEF27
0xEE51
0x74B4
0xD403
0xA1A1
0xA1A2
0xA1A3

Description
Pocket detector configuration
Circle detector configuration
User record
MotionEngine Time Source Selection
UART Output Format Selection
Gyro-Integrated Rotation Vector configuration
Fusion Control Flags

Figure 28: Configuration Records

4.3.27

Version Information

Version information is retrieved by using the HCOMM Product ID Request message.

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5.0
5.1

SH-2 Reference Manual

Operation
Sensor Metadata

Each sensor has a set of static metadata associated with it. This metadata provides information
about the sensor’s capabilities and limitations. The metadata available for each sensor is
 Vendor ID
 Sensor driver version
 Sensor-specific metadata
 Name string
 Maximum range
 Minimum period
 Batch buffer reserved count
 Maximum batch buffer count
 Resolution
 Power
 Bytes used in batch buffer for one sample
 Q point 1 – applies to sensor output
 Q point 2 – applies to sensor bias or sensor accuracy unless otherwise noted.
The metadata for each sensor is retrieved by performing an FRS read operation. The FRS
record ID for each sensor is listed in Figure 29.
Record ID
0xE301
0xE302
0xE303
0xE304
0xE305
0xE306
0xE307
0xE308
0xE309
0xE30A
0xE30B
0xE30C
0xE30D
0xE30E
0xE30F
0xE310
0xE311
0xE312
0xE313
0xE314
0xE315
0xE316
0xE317
0xE318
0xE319
0xE31A

Description
Raw accelerometer
Accelerometer
Linear acceleration
Gravity
Raw gyroscope
Gyroscope calibrated
Gyroscope uncalibrated
Raw magnetometer
Magnetic field calibrated
Magnetic field uncalibrated
Rotation vector
Game rotation vector
Geomagnetic rotation vector
Pressure
Ambient light
Humidity
Proximity
Temperature
Tap detector
Step detector
Step counter
Significant motion
Stability classifier
Shake detector
Flip detector
Pickup detector

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Record ID
0xE31B
0xE31C
0xE31D
0xE31E
0xE31F
0xE320
0xE321
0xE322
0xE323
0xE324

Description
Stability detector
Personal Activity classifier
Sleep detector
Tilt detector
Pocket detector
Circle detector
Heart Rate Monitor
ARVR Stabilized Rotation Vector
ARVR Stabilized Game Rotation Vector
Gyro-integrated Rotation Vector

Figure 29: Metadata Records

The format of the metadata records is shown in Figure 30 and Figure 26.
Description
Word
0
1
2
3
4
5
6
7
8
9
…
9+
SensorSpecific
Metadata
Length
…
N

MSB

LSB
Version
Range
Resolution

Revision = 3
Power
Minimum period
FIFO reserved count
FIFO max count
Vendor ID length
Batch buffer bytes
Q point 2
Q point 1
Q point 3
Sensor-Specific
Metadata Length
Sensor-Specific metadata
…
Vendor ID

…
Vendor ID

Figure 30: Metadata Record Format – Revision 3

Description
Word
0
1
2
3
4
5
6
7
8

MSB

LSB
Version
Range
Resolution

Revision = 4
Power
Minimum period
FIFO reserved count
FIFO max count
Vendor ID length
Batch buffer bytes
Q point 2
Q point 1
Q point 3
Sensor-Specific
Metadata Length

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Description
Word
9
10
…
10 +
SensorSpecific
Metadata
Length
…
N

MSB

LSB
Maximum period
Sensor-Specific metadata
…
Vendor ID

…
Vendor ID

Figure 31: Metadata Record Format – Revision 4

Version

Identifies the physical sensor/driver/fusion versions for a given
sensor. The elements within this field are updated when a
component changes in a manner that affects the output of the
sensor.
LSB – ME version
Byte 1 – MH version
Byte 2 – SH version
MSB – 0x00

Range

The range of the sensor. The format is unsigned fixed point. The
units and Q point are the same as those used in the sensor’s
input report.

Resolution

The resolution of the sensor. The format is unsigned fixed point.
The units and Q point are the same as those used in the sensor’s
input report.

Power

The power used by the sensor in mA when operating. The format
is unsigned fixed point. The Q point is 10.

Revision

Indicates the revision of the metadata record.

Minimum period

An unsigned integer indicating the minimum operating period in
microseconds of the sensor.

FIFO max count

The maximum number of samples that can be stored in the batch
buffer.

FIFO reserved
count

The number entries reserved in the batch FIFO for this sensor

Batch buffer bytes

The number of bytes used in the batch buffer to store one entry.

Vendor ID length

The length of the vendor ID in bytes.

Q point 1

A signed 16-bit integer indicating the Q point of the sensor data
fields.

Q point 2

A signed 16-bit integer indicating the Q point of the sensor bias

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or accuracy fields. This field is applicable only to sensors that
have bias or accuracy outputs as well as data outputs.
Sensor-Specific
Metadata length

An unsigned 16-bit integer indicating how many bytes are used
for sensor-specific metadata. 0 if there is no additional metadata.
This value must be a multiple of four.

Q point 3

A signed 16-bit integer indicating the Q point of the sensor data
change sensitivity.

Maximum period

An unsigned integer indicating the maximum operating period in
microseconds of the sensor.

Sensor-Specific
Metadata

Some sensors expose additional information (e.g. Personal
activity classifier exposes a bitmap representing the set of
supported classification states). This area is used for such
information. This field is padded with zeroes if the length is not a
multiple of four.

Vendor ID

The vendor ID is a character string that lists the vendor name
and part number. It is null terminated. The first byte starts in the
LSB of the first word. This field is padded with zeroes if the length
of the vendor ID is not a multiple of four.

5.1.1 Sensor-Specific Metadata
Sensors may need to expose more detailed information than the basic set of fields above. The
format of these sensors’ Sensor-specific Metadata is described here.

5.1.1.1

Personal Activity Classifier Metadata (0xE31C)

The sensor-specific metadata length is 4.
The sensor-specific metadata is structured as shown in Figure 32.

Description
Byte

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

…

…

…

…

…

…

1
2
3

…
…
Reserved

…
…
Classification
30 supported

…
…
…

…
…
…

…
…
…

…
…
…

Classification
1 supported
…
…
…

Classification
0 supported
…
…
…

Figure 32: Personal Activity Classifier Sensor-Specific Metadata.

5.2

Input Reports

The SH-2 returns sensor data to the host via input reports. Each sensor has its own input report.
Input reports are sent at a rate specified by the host. This rate may either be synchronous to the
sensor’s operating rate or asynchronous. Input reports may also be requested by the host at

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any time. The SH-2may also be configured to send input reports only if thresholds are
exceeded. Each sensor has its own set of thresholds. If a threshold is configured then the SH-2
will send reports at the requested rate only if the sensor output exceeds the threshold.
Sensor data is sent to the host on either the “Wakeup” SHTP channel or the “Normal” SHTP
channel, depending on whether a sensor has been configured as a wakeup sensor or not (see
[2]).
The Gyro-integrated Rotation Vector is reported on a separate “gyroRV” SHTP channel to
facilitate traffic prioritization and other optimizations.
Input reports are also used to send configuration responses to the host. Configuration input
reports will be sent on the SHTP “control” channel (see [2]).

5.3

Output Reports

Output reports are used to send configuration information to the SH-2.

5.4

Feature Reports

Sensor operation is controlled through feature reports. Setting a feature report for a sensor
causes operation of that sensor to change to comply with the settings in the feature report.
Getting a feature report returns the current operation configuration of the sensor. The operations
that can be controlled by feature reports are described in the following sections. These
descriptions provide an overview of how to control sensor operation. In cases where specific
field in feature reports are mentioned see section 6.0 for detailed information about those fields.

5.4.1 Rate Control
Sensor operating rate is controlled through the report interval field. When set to zero the sensor
is off. When set to a non-zero value the sensor generates reports at that interval or more
frequently. If the sensor cannot operate as quickly as requested, it will operate at its minimum
interval, if possible. Input reports are generated at the operating rate of the sensors.
Please note that while active, the Gyro-Integrated Rotation Vector (6.5.44) may cause a
reduction in both the nominal and actual reporting periods for fusion outputs for given requested
periods. For example, a 400 Hz Game Rotation Vector may drop to 100 Hz to permit full-speed
operation of the Gyro-Integrated Rotation Vector.

5.4.2 Threshold Control
Each sensor has a configurable reporting threshold used to determine if an input report should
be sent or not. The reporting threshold is set using the change sensitivity field. Change
sensitivities are either absolute or relative. Absolute sensitivities are evaluated to determine if
the current output values exceed the change sensitivity. Relative sensitivities are evaluated to
determine if the current output has changed relative to the previous output by an amount that
exceeds the change sensitivity.

5.4.3 Batch Operation
Batching causes the sensor to buffer its input reports until they can be sent. There are two batch
buffers. The first buffer is a circular buffer. When the SH-2 in on, reports are sent based on a
delay interval or when the buffer is full. When the SH-2 is asleep, reports are queued in the
buffer until the buffer is full. New sensor reports then overwrite the oldest reports in the buffer.
When the SH-2 is turned on the reports in the buffer are sent.

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The second buffer is a wake-on-full buffer. When the SH-2 is on or asleep, reports are sent
based on a delay interval or when the buffer is full. When the SH-2 is asleep, reports are
queued in the buffer until the buffer is full. When the buffer is full, the SH-2 wakes the AP and
sends the reports.
In cases where reports are sent when the buffer is full, they are sent soon enough to prevent the
buffer from actually overflowing. Thus, no reports are lost.

5.5

Sensor Triggering

Sensors report events based on trigger modes. The trigger modes are:



Continuous – events are reported continuously at the report interval
On-change – events are reported only if the sensor’s output has changed. In addition,
events are reported no more frequently than once every report interval
 One-shot – a single event is reported and then the sensor turns off
 Special – reporting requirements are explained in the section on that sensor’s report
 Wake-up – When the sensor has a report to send, it can wake the host in order to send
the report. i.e. it can cause the system to exit sleep mode.
 Always-on – The sensor remains on, even during periods of sleep
The trigger mode for each sensor, except the significant motion detector, can be configured as
continuous, on-change or special. The trigger mode for the significant motion detector is always
one-shot. In addition, sensors can be configured to wake up the application processor. The
trigger mode and wake-up capability for each sensor when configured for an Android system is
shown in Figure 33.
Note the interaction between “wake-up” and “always-on.” A sensor may be configured as
always-on, but not wakeup. In this mode, the sensor will continue to run and log data to the nonwakeup batch buffer while the hub is asleep. When a (different) wakeup sensor triggers, the
buffered data from all sensors is delivered. Thus, the host will get the data from the wakeup
sensor and then the backlog of data from the non-wakeup, but always-on sensors. It is generally
not useful to configure a sensor as “wake-up” but not “always-on.”

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always-on

wake-up

special

one-shot

Output
Raw accelerometer
Acceleration
Linear acceleration
Gravity
Raw gyroscope
Gyroscope calibrated
Gyroscope uncalibrated
Raw magnetometer
Magnetic field calibrated
Magnetic field uncalibrated
Rotation vector
Game rotation vector
Geomagnetic rotation vector
ARVR-Stabilized Rotation vector
ARVR-Stabilized Game rotation vector
Pressure
Ambient light
Humidity
Proximity
Temperature
SAR
Tap detector
Step detector
Step counter
Significant motion
Stability classifier
Shake detector
Flip detector
Pickup detector
Stability detector
Personal Activity Classifier
Sleep detector
Tilt detector
Pocket Detector
Circle detector

on-change

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continuous

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X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

X

X
X
X

X
X

X

X
X
X
X
X
X
X
X
X
X

X
X
X

X
X
X
X

Figure 33: Sensor Trigger Modes

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6.0
6.1

SH-2 Reference Manual

Report Descriptions
Report ID Convention

The report ID is shown as byte 0 in the reports defined throughout the following sections.

6.2

Summary

The following table summarizes all the reports in use with SH-2. Direction is relative to the host
(e.g. “write” indicates transmission of data from host to hub).
SHTP Channel

Direction

SH-2 Control
SH-2 Control
SH-2 Control
Wakeup/Normal
Wakeup/Normal
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
SH-2 Control
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal

W
W
W
R
R
W
R
W
W
W
W
R
W
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R

Report
ID
0xFE
0xFD
0xFC
0xFB
0xFA
0xF9
0xF8
0xF7
0xF6
0xF5
0xF4
0xF3
0xF2
0xF1
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
0x17
0x18

Description
Get Feature Request
Set Feature Command
Get Feature Response
Base Timestamp
Timestamp Rebase
Product ID Request
Product ID Response
FRS Write Request
FRS Write Data
FRS Write Response
FRS Read Request
FRS Read Response
Command Request
Command Response
Accelerometer
Gyroscope
Magnetic Field
Linear Acceleration
Rotation Vector
Gravity
Uncalibrated Gyroscope
Game Rotation Vector
Geomagnetic Rotation Vector
Pressure
Ambient Light
Humidity
Proximity
Temperature
Uncalibrated Magnetic Field
Tap Detector
Step Counter
Significant Motion
Stability Classifier
Raw Accelerometer
Raw Gyroscope
Raw Magnetometer
SAR
Step Detector

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SHTP Channel

Direction

Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal
Wakeup/Normal

R
R
R
R
R
R
R
R
R
R
R
R

Report
ID
0x19
0x1A
0x1B
0x1C
0x1E
0x1F
0x20
0x21
0x22
0x23
0x28
0x29

Description
Shake Detector
Flip Detector
Pickup Detector
Stability Detector
Personal Activity Classifier
Sleep Detector
Tilt Detector
Pocket Detector
Circle Detector
Heart Rate Monitor
ARVR-Stabilized Rotation Vector
ARVR-Stabilized Game Rotation Vector

Figure 34: Report ID List

6.3

Configuration Reports

Configuration reports are read and written using messages. These messages are described in
the following sections. Some configuration reports are used to collect information. Some
configuration reports are used to read and write configuration records.

6.3.1 Product ID Request (0xF9)
The product ID request is used to request product ID information from the FSP3xx.
Byte
0
1

Description
Report ID = 0xF9
Reserved

Figure 35: Product ID Request

6.3.2 Product ID Response (0xF8)
The product ID response returns product ID information about the FSP3xx.
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12

Description
Report ID = 0xF8
Reset Cause
SW Version Major
SW Version Minor
SW Part Number LSB
SW Part Number …
SW Part Number …
SW Part Number MSB
SW Build Number LSB
SW Build Number …
SW Build Number …
SW Build Number MSB
SW Version Patch LSB

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Byte
13
14
15

Description
SW Version Patch MSB
Reserved
Reserved

Figure 36: Product ID Response

Reset Cause

The last cause of the processor reset. Only reported for the
overall system ID. Subsystem Product IDs will report Not
Applicable.
0 – Not Applicable
1 – Power On Reset
2 – Internal System Reset
3 – Watchdog Timeout
4 – External Reset
5 – Other

SW Version:

software version major (8 bits).minor (8 bits).patch (16 bits)

SW Part Number:

32-bit value representing the software part number

SW Build Number:

32-bit software build number

6.3.3 FRS Write Request (0xF7)
The FRS write request is used to initiate writing an FRS record.
Byte
0
1
2
3
4
5

Description
Report ID = 0xF7
Reserved
Length LSB
Length MSB
FRS Type LSB
FRS Type MSB

Figure 37: FRS Write Request

Length:

length in 32-bit words of the record to be written. If the length is set
to 0 then the record is erased.

FRS Type:

FRS record type (see Figure 28)

6.3.4 FRS Write Data Request (0xF6)
The FRS write data request is sent to write data to the record indicated by a previous write
request. Only one FRS operation may be in progress at any one time.
Byte
0
1
2
3
4
5

Description
Report ID = 0xF6
Reserved
Offset LSB
Offset MSB
Data0 LSB
Data0 …

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Byte
6
7
8
9
10
11

Description
Data0 …
Data0 MSB
Data1 LSB
Data1 …
Data1 …
Data1 MSB

Figure 38: FRS Write Data Request

Offset:

offset, in 32-bit words, from the beginning of the record indicating
where in the record the data is to be written

Data0/1:

32-bit words of data to be written to the FRS record

The offset field is used to detect missing or put of order write data requests. When writing a
record, the write data requests must be supplied in order, with both data0 and data1 fields used.
If the record contains an odd number of words then the final write data request must use data0.

6.3.5 FRS Write Response (0xF5)
The write response report indicates the status of a write operation.
Byte
0
1
2
3

Description
Report ID = 0xF5
Status/Error
Word Offset LSB
Word Offset MSB

Figure 39: FRS Write Response

Status/Error:

0 – word(s) received
1 – unrecognized FRS type
2 – busy
3 – write completed
4 – write mode entered or ready
5 – write failed
6 – data received while not in write mode
7 – invalid length
8 – record valid (the complete record passed internal validation
checks)
9 – record invalid (the complete record failed internal validation
checks)
10 – device error (DFU flash memory device unavailable)
11 – record is read only
12-255 – reserved

Word Offset:

the number of words offset from the beginning of the record for the
most recently received write data request

An FRS write response is generated for each write request or write data request.

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6.3.6 FRS Read Request (0xF4)
The FRS read request is used to retrieve an FRS record from the FSP3xx. Only one FRS
operation may be in progress at a time. If a Read Request is issued before the first read
operation is complete, it will be responded to with a Read Response indicating BUSY and then it
will complete the already in-progress read operation.
Byte
0
1
2
3
4
5
6
7

Description
Report ID = 0xF4
Reserved
Read Offset LSB
Read Offset MSB
FRS Type LSB
FRS Type MSB
Block Size LSB
Block Size MSB

Figure 40: FRS Read Request

Read Offset:

offset, in 32-bit words, from the beginning of the FRS record at which
to begin the read operation. The first word in an FRS record is word 0.

FRS Type:

FRS record type to read (see Figure 28)

Block Size:

number of 32-bit words to read. If the block size is zero then the entire
record beginning at the read offset is returned

6.3.7 FRS Read Response (0xF3)
The FRS read response report is used to return the contents of an FRS record. Once a read
request has been received, the FSP3xx generates read responses until the request record or
portion of a record is returned. Only one FRS operation may be in progress at a time.
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Report ID = 0xF3
Data Length (bits 7:4)
Word Offset LSB
Word Offset MSB
Data0 LSB
Data0 …
Data0 …
Data0 MSB
Data1 LSB
Data1 …
Data1 …
Data1 MSB
FRS Type LSB
FRS Type MSB
Reserved
Reserved

Status (bits 3:0)

Figure 41: FRS Read Response

Data Length:

the number of data words contained within the message.

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Status:

0 – no error
1 – unrecognized FRS type
2 – busy
3 – read record completed
4 – offset out of range
5 – record empty
6 – read block completed (if block size requested)
7 – read block completed and read record completed (if block size
requested)
8 – device error (DFU flash memory device unavailable)
9-15 – reserved

Word Offset:

the number of words offset from the beginning of the record

Data0/1:

between 0 and 2 32-bit words of data from and FRS record. If only 1
word is present then it will be in the data0 field.

FRS Type:

indicates to which type of FRS record the data belongs (see
Section 4.0)

6.3.8 Command Request (0xF2)
The command request is used to ask the SH-2 to perform some special operation or report
some special data that is not part of normal sensor operation.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Description
Report ID = 0xF2
Sequence number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Figure 42: Command Request

Sequence
number

A monotonically incrementing uint8_t that rolls over. It is used to detect
missing commands and to synchronize responses

Command

A unit8_t in the range of 1-127 indicating the command. 0 and 128-255
are reserved.

P0 – P9

A set of command-specific parameters. The interpretation of these
parameters is defined for each command.

6.3.9 Command Response (0xF1)
The command response is used to report the results of some special operation or some special
data that is not part of normal sensor operation.

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Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Report ID = 0xF1
Sequence number
Command
Command sequence number
Response sequence number
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

Figure 43: Command Response

Sequence
number

A monotonically incrementing uint8_t that rolls over. It is used to detect
missing responses

Command

A unit8_t indicating the command being responded to. A value of with
the most significant bit set indicates that the response was
autonomously generated and is not associated with a command
request. Bits 6-0 indicate the command that the response corresponds
to. That is, bits 6-0 identify how to interpret the response.

Command
sequence
number

The sequence number from the command request for which the
response was returned. It is used to synchronize commands and
responses. This field is set to 0 for unsolicited responses.

Response
sequence
number

Some commands may require multiple responses. This is a
monotonically incrementing uint8_t that counts responses within a
group of responses to a single request. It may rollover. It restarts at 0
with each new response group. A response group may consist of only
one response.

R0 – R10

A set of response values. The interpretation of these values is specific
to the response for each command.

6.4

Commands

A set of commands has been defined to support a variety of operations on the sensor hub. For
each command id, a Command Message and associated Response message are usually
defined. (A few cases define only a command or only a response.) The definitions of the
command and response formats for each command id are defined in the following sections.
The following table summarizes the command identifiers defined to date:
Id
1
2

Name
Errors
Counter

Description
Command and Response to access error queue. See section 6.4.1
Command and Response to access counters. See section 6.4.3

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Id
3
4
5
6
7
8
9
10
11

SH-2 Reference Manual

Name
Tare
Initialize
Reserved
DCD
ME CAL
Reserved
DCD Save
Oscillator
Clear DCD
and Reset

Description
Command and Response to operate on tare. See section 6.4.4
Reinitialize sensor hub components. See section 6.4.5
ID 5 is not currently in use. It is reserved for future use.
Command to save DCD. See section 6.4.6
Command and Response to configure ME Calibration. See section 6.4.7
Deprecated.
Command to configure periodic saving of DCD. See section 6.4.6
Command to retrieve the oscillator type used in the clock system.
Command to clear the in-memory DCD state and perform a chip reset. See
section

Figure 44: Command Identifiers

6.4.1 Report Errors (0x01)
The SH-2 maintains a queue of errors. The report error command is used to retrieve values
from this queue. The usage of parameters and response values is shown below. The report
error command may generate multiple responses. The SH-2 will send as many responses as
necessary to send all the errors in its queue. Every error response ends with a response with
the error source set to 255, indicating that there are no more errors to report.
Byte
0
1
2
3

Name
Report ID
Sequence
Number
Command
P0

4
5
6
7
8
9
10
11

P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See section 6.3.8.
0x01 – report all errors in the error queue
The severity of errors to report. Errors of this severity and higher will be
reported. 0 – highest priority.
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 45: Report Errors Command

Byte
0
1
2
3

4

5

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0

Description
0xF1- Command Response
See Section 6.3.9
0x01 – report all errors in the error queue
See Section 6.3.9

See Section 6.3.9

Severity – the severity of the error currently being reported

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Byte
6

Name
R1

7

R2

8
9
10
11
12
13
14
15

R3
R4
R5
R6
R7
R8
R9
R10

Description
Error sequence number. A monotonically incrementing uin8_t that counts all
the errors generated for the reported severity. It may rollover.
Error source. 0 – reserved, 1 – MotionEngine, 2 – MotionHub, 3 – SensorHub,
4 – Chip level executable, 5-254 reserved. 255 – no error to report.
Error. See library API
Error module. See library API
Error code. See library API
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 46: Report Errors Response

6.4.2 Perform Self-Test
TBD

6.4.3 Counter Commands (0x02)
Counter commands are specified with a command byte of 2. Sub-commands are specified by
the P0 byte.

6.4.3.1

Get Counts (0x00)

Retrieve the number of times a specified sensor has produced samples, and what has been
done with those samples.
Offered = Number of samples produced by underlying data source.
On = Number of “Offered” samples while this sensor was requested by host.
Accepted = Number of “On” samples that passed decimation filter.
Attempted = Number of “Accepted” samples that passed threshold requirements and had
transmission to the host attempted.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x02 – Counter command
0x00 – Sub-command: get counts
Sensor ID
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 47: Get Counts Command

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These counts are returned in a pair of responses. The response sequence number (0 or 1)
indicates the types of counts it contains.
Byte
0
1
2
3

4

5
6
7
8
9
10
11
12
13
14
15

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

Description
0xF1- Command Response
See Section 6.3.9
0x02 – Counter command
See 6.3.9

See 6.3.9

Sensor ID
Status (0= invalid sensor requested, 1=valid sensor requested)
Reserved
Count Offered (Sequence Number=0) Count On (Sequence Number=1) LSB
Count Offered (SN=0) Count On (SN=1) …
Count Offered (SN=0) Count On (SN=1) ….
Count Offered (SN=0) Count On (SN=1) MSB
Count Accepted (SN=0) Count Attempted (SN=1) LSB
Count Accepted (SN=0) Count Attempted (SN=1) …
Count Accepted (SN=0) Count Attempted (SN=1) ….
Count Accepted (SN=0) Count Attempted (SN=1) MSB

Figure 48: Get Counts Response

6.4.3.2

Clear Counts (0x01)

Clear all counters for a given sensor to 0.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x02 – Counter command
0x01 – Sub-command: clear counts
Sensor ID
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 49: Clear Counts Command

6.4.4 Tare (0x03)
Tare commands are specified with a Command byte of 3. Sub-commands are specified by the
P0 byte.

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6.4.4.1

Tare Now (0x00)

This command instructs SH-2 to perform a tare operation along one or more axis. Currently the
following axes are supported:
P1 = 0x07: (X,Y, Z). This tares with rotation around all axes. This will reorient all motion
outputs (e.g. accelerometer, gyroscope, magnetometer, rotation vectors).
P1 = 0x04: (Z): This will tare with a rotation around Z, which changes the heading, but not the
tilt. The Z axis will be defined by the current reorientation.
If P2 is 0 (Rotation Vector) or 2 (Geomagnetic Rotation Vector), then this will reorient all motion
outputs.
If P2 is 1 (Gaming Rotation Vector), then this will only tare the Gaming Rotation Vector. A Zaxis Gaming Rotation tare cannot be persistent, because the Gaming Rotation Vector has no
absolute reference for heading.
If P2 is 3, 4, or 5 (Gyro-Integrated Rotation Vector, ARVR-Stabilized Rotation Vector, ARVRStabilized Game Rotation Vector), then the tare will be performed on the underlying rotation
vector (Rotation Vector or Game Rotation Vector). The derived vector will be immediately
updated to match the value of the underlying rotation vector at this time.
Byte
0
1
2
3
4
5

Name
Report ID
Sequence
Number
Command
P0
P1
P2

6
7
8
9
10
11

P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x03 – Tare command
0x00 – Subcommand: Perform Tare now
Bitmap of axes to tare: Bit 0= X, Bit 1= Y, Bit 2= Z
Rotation Vector to use as basis for tare.
0: Rotation Vector
1: Gaming Rotation Vector
2: Geomagnetic Rotation Vector
3: Gyro-Integrated Rotation Vector
4: ARVR-Stabilized Rotation Vector
5: ARVR-Stabilized Game Rotation Vector
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 50: Tare Now Command

6.4.4.2

Persist Tare (0x01)

This command instructs SH-2 to persist the results of the last tare operation to flash for use at
the next system restart. These results are stored in the master Sensor Orientation configuration
record, individual sensor orientation records are not modified. Note that this only persists the
tare applied to rotation vector and geomagnetic rotation vector.
Byte
0

Name
Report ID

Description
0xF2 – Command Request

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Byte
1
2
3
4
5
6
7
8
9
10
11

Name
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
See Section 6.3.8.
0x03 – Tare command
0x01 – Persist Tare
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 51: Persist Tare Command

6.4.4.3

Set Reorientation (0x02)

This command instructs SH-2 to set the current run-time sensor reorientation. Note that this
does not replace any persistent tare settings in the master Sensor Orientation configuration
record. Persistent tare settings must be cleared by deleting the Sensor Orientation configuration
record.
To clear the current tare, set P1-P8 to 0x00.
The rotation vector is a signed, 16-bit 2’s-complement fixed point number with a Q-point of 14.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x03 – Tare Command
0x02 – Set Reorientation
Rotation quaternion X LSB
Rotation quaternion X MSB
Rotation quaternion Y LSB
Rotation quaternion Y MSB
Rotation quaternion Z LSB
Rotation quaternion Z MSB
Rotation quaternion W LSB
Rotation quaternion W MSB

Figure 52: Set Reorientation Command

6.4.5 Initialization (0x04)
The initialize command requests that the sensor hub reinitialize itself or one of its subsystems.
The response is sent unsolicited if the sensor hub itself resets.

6.4.5.1

Initialize Command

This command is sent by the host to re-initialize the sensor hub (or one of its subsystems.)
Byte
0

Name
Report ID

Description
0xF2 – Command Request

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Byte
1
2
3
4
5
6
7
8
9
10
11

Name
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
See Section 6.3.8.
0x04 – Initialize command
Subsystem
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 53: Initialize Command

The subsystem field indicates which component of the sensor hub should be reinitialized:
Value
0
1
Others

Subsystem
None
SensorHub
Reserved

Description
No Operation.
Reinitialize the entire sensor hub.
Reserved

Figure 54: Initialize Command Subsystems

6.4.5.2

Initialize Response

The sensor hub responds to the Initialize command with an Initialize Response. In the case
where the sensor hub reinitializes itself, this response is unsolicited. An unsolicited response is
also generated after startup.
Byte
0
1
2
3

4

5
6
7
8
9
10
11
12
13
14
15

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

Description
0xF1- Command Response
See Section 6.3.9
0x04 – Initialize, 0x84 – Initialize (unsolicited)
See 6.3.9

See 6.3.9

Status (0 – successful. 1 – Operation failed)
Subsystem
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 55: Initialize Response

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6.4.6 Save DCD (0x06)
The Save DCD command requests that the sensor hub save the current DCD. Upon
completion, a Save DCD Response will be sent.

6.4.6.1

Save DCD Command

This command is sent by the host to save the DCD.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x06 – Save DCD Command
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 56: Save DCD Command

6.4.6.2

Save DCD Response

The sensor hub responds to the Save DCD command with a Save DCD Response containing a
success/failure status.
Byte
0
1
2
3

4

5
6
7
8
9
10
11
12
13
14
15

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

Description
0xF1- Command Response
See Section 6.3.9
0x06 – Save DCD
See 6.3.9

See 6.3.9

Status (0 – success. Non Zero – Operation failed)
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 57: Save DCD Response

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6.4.7 ME Calibration Commands (0x07)
The ME Calibration command requests tell the sensor hub to enable/disable the accelerometer,
gyro and magnetometer calibration routines and can read back the enable/disable state of each
of these routines.

6.4.7.1

Configure ME Calibration Command

This command is sent by the host to configure the ME calibration of the accelerometer, gyro and
magnetometer giving the host the ability to control when calibration is performed.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x07 – ME Calibration Command
Accel Cal Enable (1 – enabled, 0 – disabled)
Gyro Cal Enable (1 – enabled, 0 – disabled)
Mag Cal Enable (1 – enabled, 0 – disabled)
0x00 – Subcommand: Configure ME Calibration
Planar Accel Cal Enable (1 – enabled, 0 – disabled)
Reserved
Reserved
Reserved
Reserved

Figure 58: Configure ME Calibration Command

6.4.7.2

Get ME Calibration Command

This command is sent by the host to request the enable/disable state of the accelerometer, gyro
and magnetometer calibration routines.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x07 – ME Calibration Command
Reserved
Reserved
Reserved
0x01 – Subcommand: Get ME Calibration
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 59: Get ME Calibration Command

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6.4.7.3

ME Calibration Response

The sensor hub responds to the Configure ME Calibration command with a Configure ME
Calibration Response containing a success/failure status and the enable/disable state of the
accelerometer, gyro and magnetometer calibration routines.
Byte
0
1
2
3

4

5
6
7
8
9
10
11
12
13
14
15

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

Description
0xF1- Command Response
See Section 6.3.9
0x07 – Configure ME Calibration
See 6.3.9

See 6.3.9

Status (0 – success. Non Zero – Operation failed)
Accel Cal Enable (1 – enabled, 0 – disabled)
Gyro Cal Enable (1 – enabled, 0 – disabled)
Mag Cal Enable (1 – enabled, 0 – disabled)
Planar Accel Cal Enable (1 – enabled, 0 – disabled)
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 60: Configure ME Calibration Response

6.4.8 Configure Periodic DCD Save (0x09)
The Configure Periodic DCD Save command configures the automatic saving of DCD. There is
no response to this command. This command does not inhibit the Save DCD command.

6.4.8.1

Configure Periodic DCD Save Command

This command is sent by the host to enable or disable the saving of DCD on a periodic basis.
Byte
0
1
2
3

Name
Report ID
Sequence
Number
Command
P0

4
5
6
7
8
9
10
11

P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x09– Configure DCD Save Command
0x00 – Enable Periodic DCD Save
0x01 – Disable Periodic DCD Save
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

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Figure 61: Configure Periodic Save DCD Command

6.4.9 Get Oscillator Type (0x0A)
The Get Oscillator Type command is used to get information about the oscillator type used in
the clock system of the SH-2.

6.4.9.1

Get Oscillator Type Command

This command is sent by the host to request information about the clock system of the SH-2.
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x0A – Get Oscillator Type Command
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 62: Get Oscillator Type Command

6.4.9.2

Get Oscillator Type Response

The sensor hub responds to the Get Oscillator Type command with a Get Oscillator Type
Response containing the oscillator type used by the SH-2 clock system.
Byte
0
1
2
3

4

5
6
7
8
9
10
11
12
13

Name
Report ID
Sequence
Number
Command
Command
Sequence
Number
Response
Sequence
Number
R0
R1
R2
R3
R4
R5
R6
R7
R8

Description
0xF1- Command Response
See Section 6.3.9
0x0A – Get Oscillator Type Command
See 6.3.9

See 6.3.9

Oscillator Type (0 – internal Oscillator, 1 – external crystal, 2 – external clock )
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

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Byte
14
15

SH-2 Reference Manual

Name
R9
R10

Description
Reserved
Reserved

Figure 63: Get Oscillator Type Response

6.4.10

Clear DCD and Reset (0x0B)

The sensor hub stores updated Dynamic Calibration Data to RAM frequently. At non-power-up
reset, the hub will persist the last-stored DCD from RAM to FRS. In order to prevent this from
happening (e.g. if one desires to fully clear DCD state), this command performs an atomic clearDCD (from RAM) and system reset.
The recommended sequence for completely resetting DCD state is:
1. Reset hub (via pin toggle, reset command, or Clear DCD and Reset Command)
2. Delete flash copy of DCD via FRS: see 6.3.3.
3. Issue Clear DCD and Reset Command.

6.4.10.1 Clear DCD and Reset Command
Clear any copy of DCD stored in RAM and perform a chip reset immediately. No response is
sent for this command, though the hub will report an unsolicited Initialization Response as in a
standard reset (see 6.4.5.2).
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Name
Report ID
Sequence
Number
Command
P0
P1
P2
P3
P4
P5
P6
P7
P8

Description
0xF2 – Command Request
See Section 6.3.8.
0x0B – Clear DCD and Reset
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved

Figure 64: Clear DCD and Reset Command

6.5

Sensor Reports

Sensor feature reports are used to control and configure sensors, and to retrieve sensor
configuration. Sensor input reports are used to send sensor data to the host.
The sensor input reports use fixed point formats for their data fields. Some sensors report both
the sensor data output and either the sensor bias or the sensor accuracy. For sensors that have
both types of outputs, the Q point of each type of output may be different. The default Q point
for each type is provided in the following sections about the reports for each sensor. For SH-2
systems using revision 1 or later of the sensor metadata record, the Q points are provided in the

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metadata record. If there is a difference between the Q point listed below and that of the
metadata record, the metadata record takes precedence.

6.5.1 Common Fields
The sensor feature and input reports have a number of fields in common across many sensors.
These common fields and their meaning are listed in Figure 65. Fields that are specific to a
sensor are explained in that sensors report.
Field
Report ID
Sequence number

Report Interval
Batch Interval

Feature flags

Change sensitivity absolute

Change sensitivity relative

Sensor-Specific
Configuration word
Status

Delay LSB

Description
Report ID
8-bit unsigned integer used to track reports. The
sequence number increments once for each report sent.
Gaps in the sequence numbers indicate missing or
dropped reports.
32-bit unsigned integer representing the interval in
microseconds between asynchronous input reports
32-bit unsigned integer controlling the maximum delay (in
microseconds) between the time that a sensor is sampled
and the time that its data can be reported. The value 0 is
reserved for “do not delay” and the value 0xFFFFFFFF is
reserved for “never trigger delivery on the basis of
elapsed time”
A bit field that enables various features for a sensor.
Bit 0: change sensitivity type.
0 – absolute
1 – relative
Bit 1: change sensitivity enable
0 – disabled
1 – enabled
Bit 2: wake-up enable
0 – disabled
1 – enabled
Bit 3: always-on enable (run sensor while hub is in “sleep”
mode)
0 – disabled
1 – enabled
Bit 4: reserved
Bit 5: reserved
Bit 6: reserved
Bit 7: reserved
16-bit signed fixed point integer representing the value a
sensor output must exceed in order to trigger another
input report.
16-bit signed fixed point integer representing the amount
by which a sensor output must change from the previous
input report in order to trigger another input report.
32-bit field available for use by sensors requiring
additional configuration options.
Bits 1:0 – indicate the status of a sensor.
0 – Unreliable
1 – Accuracy low
2 – Accuracy medium
3 – Accuracy high
Bits 7:2 – Delay upper bits: 6 most-significant bits of
report delay. See blow.
8 least-significant bits of report delay. Units are 100 us.

Figure 65: Common Report Fields

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6.5.2 Common Dynamic Feature Report
All sensors use the same format for a feature report. This format is shown in Figure 66.
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Feature Report ID
Feature flags
Change sensitivity [absolute | relative] LSB
Change sensitivity [absolute | relative] MSB
Report Interval LSB
Report Interval
Report Interval
Report Interval MSB
Batch Interval LSB
Batch Interval
Batch Interval
Batch Interval MSB
Sensor-specific configuration word LSB
Sensor-specific configuration word
Sensor-specific configuration word
Sensor-specific configuration word MSB

Read/Write
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W

Figure 66: Common Feature Report

The type of change sensitivity may be either absolute or relative. The units of change sensitivity
are normally the same as that of the input reports. The Q point of the change sensitivity is
normally the same as that of the input reports. Any variations from this normal arrangement are
explained in the individual sensor’s report section. For some sensors the change sensitivity is
redefined to have a meaning that is applicable to that particular sensor. In these cases use of
the change sensitivity field is explained in the feature report section for that sensor.

6.5.3 Get Feature Request (0xFE)
Get-Feature requests are issued by sending the following report to SH-2. These are sent on the
SH-2 control channel from host to hub.
Byte
0
1

Description
Report ID=0xFE
Feature Report ID

Figure 67: Get Feature Request (0xFE)

“Feature Report ID” is set to the ID of the feature report that is to be obtained. For example, to
request the Raw Accelerometer feature report, the bytes 0xFE 0x14 would be sent to SH-2. SH2 will respond by sending a Get Feature Response (6.5.5) at some point in the future.

6.5.4 Set Feature Command (0xFD)
Set-Feature commands are issued by prefixing the full feature report with 0xFD. These are sent
on the SH-2 control channel from host to hub.
Byte
0
1
2
3

Description
Report ID = 0xFD
Feature Report ID
Feature flags
Change sensitivity [absolute | relative] LSB

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Byte
4
5
6
7
8
9
10
11
12
13
14
15
16

Description
Change sensitivity [absolute | relative] MSB
Report Interval LSB
Report Interval
Report Interval
Report Interval MSB
Batch Interval LSB
Batch Interval
Batch Interval
Batch Interval MSB
Sensor-specific configuration word LSB
Sensor-specific configuration word
Sensor-specific configuration word
Sensor-specific configuration word MSB

Figure 68: Set Feature Command (0xFD)

6.5.5 Get Feature Response (0xFC)
SH-2 will respond to Get Feature Requests (6.5.3) by sending a Get Feature Response on the
control channel. These are the full feature report that was requested, prefixed with 0xFC.
Note that SH-2 protocol version 1.0.1 and higher will send Get Feature Response messages
unsolicited if a sensor’s rate changes (e.g. due to change in the rate of a related sensor).

Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

Description
Report ID = 0xFC
Feature Report ID
Feature flags
Change sensitivity [absolute | relative] LSB
Change sensitivity [absolute | relative] MSB
Report Interval LSB
Report Interval
Report Interval
Report Interval MSB
Batch Interval LSB
Batch Interval
Batch Interval
Batch Interval MSB
Sensor-specific configuration word LSB
Sensor-specific configuration word
Sensor-specific configuration word
Sensor-specific configuration word MSB

Figure 69: Get Feature Response (0xFC)

6.5.6 Force Sensor Flush (0xF0)
This is sent from the host to the hub to trigger a flush of outstanding data from a given sensor
(e.g. before its batch settings would require it). The hub may report data for other sensors as

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well. Each of these will result in the transmission of a corresponding Flush Complete report
(6.5.7) to the host.
Byte
0
1

Description
Report ID=0xF0
Sensor ID

Figure 70: Force Sensor Flush (0xF0)

6.5.7 Flush Completed (0xEF)
Report that all data from a given sensor, as of the corresponding Force Sensor flush () has been
transmitted.
Byte
0
1

Description
Report ID=0xEF
Sensor ID

Figure 71: Flush Completed (0xEF)

6.5.8 Raw Accelerometer (0x14)
The accelerometer sensor reports raw readings from the physical accelerometer MEMS sensor.
The units are ADCs. Interpretation of the reported values is sensor dependent. The report ID is
0x14.

6.5.8.1

Feature Report

The change sensitivity is applied to each axis independently.

6.5.8.2

Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Report ID = 0x14
Sequence number
Status
Delay
Accelerometer Axis X LSB
Accelerometer Axis X MSB
Accelerometer Axis Y LSB
Accelerometer Axis Y MSB
Accelerometer Axis Z LSB
Accelerometer Axis Z MSB
Reserved
Reserved
Timestamp LSB
…
…
Timestamp MSB

Figure 72: Raw Accelerometer Input Report

The timestamp field is a uint32_t. It is the time that the sample was taken as measured by a
timer running on the hub. The units are microseconds.

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6.5.9 Accelerometer (0x01)
The accelerometer sensor reports the total acceleration of the device. The units are m/s^2. The
Q point is 8. The report ID is 0x01.

6.5.9.1

Feature Report

The change sensitivity is applied to each axis independently.

6.5.9.2

Input Report
Byte
0
1
2
3
4
5
6
7
8
9

Description
Report ID = 0x01
Sequence number
Status
Delay
Accelerometer Axis X LSB
Accelerometer Axis X MSB
Accelerometer Axis Y LSB
Accelerometer Axis Y MSB
Accelerometer Axis Z LSB
Accelerometer Axis Z MSB

Figure 73: Accelerometer Input Report

6.5.10

Linear Acceleration (0x04)

The linear acceleration sensor reports the acceleration of the device minus gravity. The units
are m/s^2. The Q point is 8. The report ID is 0x04.

6.5.10.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.10.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9

Description
Report ID = 0x04
Sequence number
Status
Delay
Linear acceleration Axis X LSB
Linear acceleration Axis X MSB
Linear acceleration Axis Y LSB
Linear acceleration Axis Y MSB
Linear acceleration Axis Z LSB
Linear acceleration Axis Z MSB

Figure 74: Linear Acceleration Input Report

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SH-2 Reference Manual

Gravity (0x06)

The gravity sensor reports gravity in the device’s coordinate frame. The units are m/s^2. The Q
point is 8. The report ID is 0x06.

6.5.11.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.11.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9

Description
Report ID = 0x06
Sequence number
Status
Delay
Gravity Axis X LSB
Gravity Axis X MSB
Gravity Axis Y LSB
Gravity Axis Y MSB
Gravity Axis Z LSB
Gravity Axis Z MSB

Figure 75: Gravity Input Report

6.5.12

Raw Gyroscope (0x15)

The gyroscope sensor reports raw readings from the physical gyroscope MEMS sensor. The
units are ADCs. Interpretation of the reported values is sensor dependent. The report ID is
0x15.

6.5.12.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.12.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13

Description
Report ID = 0x15
Sequence number
Status
Delay
Gyroscope Axis X LSB
Gyroscope Axis X MSB
Gyroscope Axis Y LSB
Gyroscope Axis Y MSB
Gyroscope Axis Z LSB
Gyroscope Axis Z MSB
Gyroscope temperature LSB
Gyroscope temperature MSB
Timestamp LSB
…

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Byte
14
15

Description
…
Timestamp MSB

Figure 76: Raw Gyroscope Input Report

The timestamp field is a uint32_t. It is the time that the sample was taken as measured by a
timer running on the hub. The units are microseconds.

6.5.13

Gyroscope Calibrated (0x02)

The gyroscope calibrated sensor reports drift-compensated rotational velocity. The units are
rad/s. The Q point is 9. The report ID is 0x02.

6.5.13.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.13.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9

Description
Report ID = 0x02
Sequence number
Status
Delay
Gyroscope calibrated Axis X LSB
Gyroscope calibrated Axis X MSB
Gyroscope calibrated Axis Y LSB
Gyroscope calibrated Axis Y MSB
Gyroscope calibrated Axis Z LSB
Gyroscope calibrated Axis Z MSB

Figure 77: Gyroscope Calibrated Input Report

6.5.14

Gyroscope Uncalibrated (0x07)

The gyroscope uncalibrated sensor reports rotational velocity without drift compensation. An
estimate of drift is also reported. The units for both values are rad/s. The Q point for both values
is 9. The report ID is 0x07.

6.5.14.1 Feature Report
The change sensitivity is applied to each uncalibrated axis independently. The change
sensitivity does not apply to the bias fields.

6.5.14.2 Input Report
Byte
0
1
2
3
4

Description
Report ID = 0x07
Sequence number
Status
Delay
Gyroscope uncalibrated Axis X LSB

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Byte
5
6
7
8
9
10
11
12
13
14
15

Description
Gyroscope uncalibrated Axis X MSB
Gyroscope uncalibrated Axis Y LSB
Gyroscope uncalibrated Axis Y MSB
Gyroscope uncalibrated Axis Z LSB
Gyroscope uncalibrated Axis Z MSB
Gyroscope uncalibrated bias Axis X LSB
Gyroscope uncalibrated bias Axis X MSB
Gyroscope uncalibrated bias Axis Y LSB
Gyroscope uncalibrated bias Axis Y MSB
Gyroscope uncalibrated bias Axis Z LSB
Gyroscope uncalibrated bias Axis Z MSB

Figure 78: Gyroscope Uncalibrated Input Report

6.5.15

Raw Magnetometer (0x16)

The magnetometer sensor reports raw readings from the physical magnetometer sensor. The
units are ADCs. Interpretation of the reported values is sensor dependent. The report ID is
0x16.

6.5.15.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.15.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Report ID = 0x16
Sequence number
Status
Delay
Magnetometer Axis X LSB
Magnetometer Axis X MSB
Magnetometer Axis Y LSB
Magnetometer Axis Y MSB
Magnetometer Axis Z LSB
Magnetometer Axis Z MSB
Reserved
Reserved
Timestamp LSB
…
…
Timestamp MSB

Figure 79: Raw Magnetometer Input Report

The timestamp field is a uint32_t. It is the time that the sample was taken as measured by a
timer running on the hub. The units are microseconds.

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SH-2 Reference Manual

Magnetic Field Calibrated (0x03)

The magnetic field calibrated sensor reports the geomagnetic field calibrated for hard and soft
iron effects such that the vector is aligned with the declination and heading of Earth’s magnetic
field. The units are uTesla. The Q point is 4. The report ID is 0x03.

6.5.16.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.16.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9

Description
Report ID = 0x03
Sequence number
Status
Delay
Magnetic Field calibrated Axis X LSB
Magnetic Field calibrated Axis X MSB
Magnetic Field calibrated Axis Y LSB
Magnetic Field calibrated Axis Y MSB
Magnetic Field calibrated Axis Z LSB
Magnetic Field calibrated Axis Z MSB

Figure 80: Magnetic Field Calibrated Input Report

6.5.17

Magnetic Field Uncalibrated (0x0F)

The magnetic field uncalibrated sensor reports the geomagnetic field calibrated for soft iron
effects only. Estimates for the hard iron bias are also reported. The units for both values are
uTesla. The Q point for both values is 4. The report ID is 0x0F.

6.5.17.1 Feature Report
The change sensitivity is applied to each uncalibrated axis independently. The change
sensitivity does not apply to the hard iron bias fields.

6.5.17.2 Input Report
Byte
0
1
2
3
4
5
6
7
6
9
10
11

Description
Report ID = 0x0F
Sequence number
Status
Delay
Magnetic Field uncalibrated Axis X LSB
Magnetic Field uncalibrated Axis X MSB
Magnetic Field uncalibrated Axis Y LSB
Magnetic Field uncalibrated Axis Y MSB
Magnetic Field uncalibrated Axis Z LSB
Magnetic Field uncalibrated Axis Z MSB
Magnetic Field uncalibrated hard iron bias Axis X LSB
Magnetic Field uncalibrated hard iron bias Axis X MSB

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Byte
12
13
14
15

Description
Magnetic Field uncalibrated hard iron bias Axis Y LSB
Magnetic Field uncalibrated hard iron bias Axis Y MSB
Magnetic Field uncalibrated hard iron bias Axis Z LSB
Magnetic Field uncalibrated hard iron bias Axis Z MSB

Figure 81: Magnetic Field Uncalibrated Input Report

6.5.18

Rotation Vector (0x05)

The rotation vector sensor reports the orientation of the device. The format of the rotation vector
is a unit quaternion. The Q point is 14. In addition an estimate of the heading accuracy is
reported. The units for the accuracy estimate are radians. The Q point is 12. The report ID is
0x05.

6.5.18.1 Feature Report
The change sensitivity is applied to the angular difference between two rotation vectors. The
units for change sensitivity are radians. The change sensitivity is unsigned and the Q point is
13.

6.5.18.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13

Description
Report ID = 0x05
Sequence number
Status
Delay
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB
Accuracy estimate LSB
Accuracy estimate MSB

Figure 82: Rotation Vector Input Report

6.5.19

Game Rotation Vector (0x08)

The rotation vector sensor reports the orientation of the device. The format of the rotation vector
is a unit quaternion. The Q point is 14. The report ID is 0x08.

6.5.19.1 Feature Report
The change sensitivity is applied to the angular difference between two rotation vectors. The
units for change sensitivity are radians. The change sensitivity is unsigned and the Q point is
13.

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6.5.19.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Description
Report ID = 0x08
Sequence number
Status
Delay
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB

Figure 83: Game Rotation Vector Input Report

6.5.20

Geomagnetic Rotation Vector (0x09)

The geomagnetic rotation vector sensor reports the orientation of the device. The format of the
rotation vector is a unit quaternion. The Q point is 14. In addition an estimate of the heading
accuracy is reported. The units for the accuracy estimate are radians. The Q point is 12. The
report ID is 0x09.

6.5.20.1 Feature Report
The change sensitivity is applied to the angular difference between two rotation vectors. The
units for change sensitivity are radians. The change sensitivity is unsigned and the Q point is
13.

6.5.20.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13

Description
Report ID = 0x09
Sequence number
Status
Delay
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB
Accuracy estimate LSB
Accuracy estimate MSB

Figure 84: Geomagnetic Rotation Vector Input Report

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6.5.21

SH-2 Reference Manual

Pressure (0x0A)

The pressures sensor reports atmospheric pressure. The units are hectopascals. The Q point is
20. The report ID is 0x0A.

6.5.21.1 Feature Report
The Q point of the change sensitivity is 6.

6.5.21.2 Input Report
Byte
0
1
2
3
4
6
6
7

Description
Report ID = 0x0A
Sequence number
Status
Delay
Atmospheric pressure LSB
…
…
Atmospheric pressure MSB

Figure 85: Pressure Sensor Input Report

6.5.22

Ambient Light (0x0B)

The ambient light sensor reports the measures the amount of light entering the sensor. The
units are lux. The Q point is 8. The report ID is 0x0B.

6.5.22.1 Feature Report
The Q point of the change sensitivity is 6.

6.5.22.2 Input Report
Byte
0
1
2
3
4
5
6
7

Description
Report ID = 0x0B
Sequence number
Status
Delay
Ambient light LSB
…
…
Ambient light MSB

Figure 86: Ambient Light Sensor Input Report

6.5.23

Humidity (0x0C)

The humidity sensor reports relative humidity in the ambient air. The units are percent. The Q
point is 8. The report ID is 0x0C.

6.5.23.1 Feature Report
No special remarks.

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6.5.23.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x0C
Sequence number
Status
Delay
Relative humidity LSB
Relative humidity MSB

Figure 87: Humidity Sensor Input Report

6.5.24

Proximity (0x0D)

The proximity sensor reports distance from the device. The units are centimeters. The Q point is
4. The report ID is 0x0D.

6.5.24.1 Feature Report
The change sensitivity is applied to each axis independently.

6.5.24.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x0D
Sequence number
Status
Delay
Distance LSB
Distance MSB

Figure 88: Proximity Sensor Input Report

6.5.25

Temperature (0x0E)

The temperature sensor reports ambient temperature. The units are °C. The Q point is 7. The
report ID is 0x0E.

6.5.25.1 Feature Report
No special remarks.

6.5.25.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x0E
Sequence number
Status
Delay
Temperature LSB
Temperature MSB

Figure 89: Temperature Sensor Input Report

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6.5.26

Reserved (0x17)

6.5.27

Tap Detector (0x10)

The tap detector reports single and double taps. The report ID is 0x10.

6.5.27.1 Feature Report
The change sensitivity should be set to 0 for the tap detector.

6.5.27.2 Input Report
Byte
0
1
2
3
4

Description
Report ID = 0x10
Sequence number
Status
Delay
Taps detected

Figure 90: Tap Detector Input Report

Taps detected

Bit field.
Indicates single and double taps along each axis. The direction
flag is not valid if a tap was not detected along the associated
axis. The direction flag means that if a tap was detected and the
direction flag is set then the tap was along the positive given axis
towards the origin. For example, if the positive Z axis is pointing
out of the face of a device and the user taps on the face of the
device then the Z axis tap and direction flags will both be set. If a
tap is detected, it may be either a single or a double tap.
Bit 0 – X axis tap.
Bit 1 – X axis positive tap
Bit 2 – Y axis tap
Bit 3 – Y axis positive tap
Bit 4 – Z axis tap
Bit 5 – Z axis positive tap
Bit 6 – double tap
Bit 7 – reserved

6.5.28

Step Detector (0x18)

The step detector reports steps detected. Each report indicates a single step. The report ID is
0x18.

6.5.28.1 Feature Report
The change sensitivity should be set to 0 for the step detector.

6.5.28.2 Input Report

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Byte
0
1
2
3
4
5
6
7

Description
Report ID = 0x18
Sequence number
Status
Delay
Detect latency LSB
…
…
Detect latency MSB

Figure 91: Step Detector Input Report

Detect latency

6.5.29

The delay in microseconds from The time from when the step
occurred until the time the step was detected and reported.

Step Counter (0x11)

The step counter reports steps counted. The units are steps. The value is unsigned. The Q point
is 0. The report ID is 0x11. The step counter will wake the host at least once before the steps
field wraps around to a previously reported value.

6.5.29.1 Feature Report
No special remarks.

6.5.29.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Description
Report ID = 0x11
Sequence number
Status
Delay
Detect latency LSB
…
…
Detect latency MSB
Steps LSB
Steps MSB
Reserved
Reserved

Figure 92: Step Counter Input Report

Detect latency

The delay in microseconds from The time from when the last
step being counted occurred until the time the step count was
reported.

Steps

The number of steps counted. This is a normally incrementing
count of the number of steps taken by the user. This field may
decrement of motions previously reported as steps are
determined not to be steps. This field rolls over.

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6.5.30

Significant Motion (0x12)

The significant motion detector sends a single report when it detects significant motion. It
automatically turns itself off after sending its single report. The report ID is 0x12.

6.5.30.1 Feature Report
The change sensitivity should be set to 0 for the significant motion detector.

6.5.30.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x12
Sequence number
Status
Delay
Motion LSB
Motion MSB

Figure 93: Significant Motion Input Report

Motion

Indicates motion being reported.
1 – significant motion detected
All other values are reserved.

6.5.31

Stability Classifier (0x13)

The stability classifier sensor reports the type of stability detected. The report ID is 0x13.

6.5.31.1 Feature Report
The change sensitivity should be set to 0 for the stability classifier sensor.

6.5.31.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x13
Sequence number
Status
Delay
Stability classification
Reserved

Figure 94: Stability Classifier Input Report

Stability
Classification

Stability classification is the state of the device based on its
movement.
0 – unknown
1 – on table. The hub is at rest on a stable surface with very little
vibration.
2 – stationary. The hub’s motion is below the stable threshold but
the stable duration requirement has not been met. This output is

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only available when gyro calibration is enabled. See section
6.4.7 for details about enabling gyro calibration. When gyro
calibration is disabled, only states 0, 1, 3 and 4 are output.
3 – stable. The hub’s motion has met the stable threshold and
duration requirements.
4 – motion. The hub is moving.
5 – 255 Reserved

6.5.32

Shake Detector (0x19)

The shake detector sends a report each time it detects a shake. The report ID is 0x19.

6.5.32.1 Feature Report
The change sensitivity should be set to 0 for the shake detector.

6.5.32.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x19
Sequence number
Status
Delay
Shake LSB
Shake MSB

Figure 95: Shake Detector Input Report

Shake

A bit field that indicates the axis along which that a shake was
detected.
Bit 0 – X axis shake.
Bit 1 – Y axis shake
Bit 2 – Z axis shake
Bits 3-15 – Reserved

6.5.33

Flip Detector (0x1A)

The flip detector sends a report each time it detects a flip. The report ID is 0x1A.

6.5.33.1 Feature Report
The change sensitivity should be set to 0 for the flip detector.

6.5.33.2 Input Report
Byte
0
1
2

Description
Report ID = 0x1A
Sequence number
Status

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Byte
3
4
5

Description
Delay
Flip LSB
Flip MSB

Figure 96: Flip Detector Input Report

Flip

Indicates that a flip was detected.
1 – flip detected
All other values are reserved

6.5.34

Pickup Detector (0x1B)

The pickup detector sends a report each time it detects a pickup. The report ID is 0x1B.

6.5.34.1 Feature Report
The change sensitivity should be set to 0 for the pickup detector.

6.5.34.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x1B
Sequence number
Status
Delay
Pickup LSB
Pickup MSB

Figure 97: Pickup Detector Input Report

Pickup

Indicates that a pickup was detected.
1 – level to not level detected
2 – stopped within tilt region detected
3 – both level to not level and stopped within tilt region detected
All other values are reserved

6.5.35

Stability Detector (0x1C)

The stability detector sends a report each time it detects entry in or exit from a stable state. The
report ID is 0x1C.

6.5.35.1 Feature Report
The change sensitivity should be set to 0 for the stability detector.

6.5.35.2 Input Report
Byte
0
1

Description
Report ID = 0x1C
Sequence number

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Byte
2
3
4
5

Description
Status
Delay
Stability LSB
Stability MSB

Figure 98: Stability Detector Input Report

Stability

Bit field.
Indicates stability detector events. A value of 1 means the event
was detected.
Bit 0 – stable state entered
Bit 1 – stable state exited
All other bits are reserved

6.5.36

Personal Activity Classifier (0x1E)

6.5.36.1 Feature Report
The lower 31 bits of Sensor-Specific Configuration Word indicate which classifications are
requested (bit indices correspond with the classification states enumerated in Figure 101:
Activity Classification States). For example, to enable still (4), walking (6) and running (7), the
host would set bits 4, 6, and 7, supplying 0x000000D0 as the Sensor-Specific Configuration
Word. If any classifications are requested, the “Unknown” classification (0) will automatically be
requested.
Change sensitivity is specified in percent (0-100), and is applied to the confidence of each
classification. A report will be produced if any requested classification’s confidence change
since the last transmitted input report exceeds the specified threshold. Note that this change is
not relative to the value of the confidence. For example, a 10% change threshold, when applied
to a classification having original confidence of 80%, will trigger at 90% and 70%, not 88% and
72%.
The most significant bit of Sensor-Specific Configuration Word imposes the additional constraint
that the most-likely-state must differ from the last reported most-likely state when set.

Description
Byte

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

…

…

…

…

…

…

1
2
3

…
…
MLS
Change

…
…
Classification
30 enable

…
…
…

…
…
…

…
…
…

…
…
…

Classification
1 enable
…
…
…

Classification
0 enable
…
…
…

Figure 99: Personal Activity Classifier Feature Report.

6.5.36.2 Input Report

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Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Description
Report ID = 0x1E
Sequence number
Status
Delay
Page Number + EOS
Most likely state
Classification (10 x Page Number) confidence
Classification (10 x Page Number) + 1 confidence
Classification (10 x Page Number) + 2 confidence
Classification (10 x Page Number) + 3 confidence
Classification (10 x Page Number) + 4 confidence
Classification (10 x Page Number) + 5 confidence
Classification (10 x Page Number) + 6 confidence
Classification (10 x Page Number) + 7 confidence
Classification (10 x Page Number) + 8 confidence
Classification (10 x Page Number) + 9 confidence

Figure 100: Personal Activity Classifier Report

Page Number +
EOS

MSB is set if this is the last input report for a set of classification
results, MSB is clear if more input reports follow this one.
7 least-significant bits indicate page number in the event that
classifications are added that exceed the length of a single input
report. Results will be reported in multiple pages of no more than
10 confidence levels per page.

Most likely state

Indicates most likely current state, per Figure 101: Activity
Classification States.

Classification n
confidence

Confidence that the current state is (Page Number x 10) + n.
Confidences range from 0 to 100, but do not add up to 100 (as
activities are not mutually exclusive).

Note that the classifier may not be able to be configured to provide exactly the set of
classifications requested. In this case, confidence reports for unwanted classifications may be
masked (set to 0) internally by SH-2.
Note that if the personal activity classifier supports more than 10 classifications, all pages will be
reported (even if no classifications were requested on that page or no confidence levels on that
page exceeded the change threshold).
ID
0
1
2
3
4
5
6
7
8

Description
Unknown
In-Vehicle
On-Bicycle
On-Foot
Still
Tilting
Walking
Running
OnStairs

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Figure 101: Activity Classification States

6.5.37

Sleep Detector (0x1F)

The sleep detector sends a report each time it detects a change in sleep state. The report ID is
0x1F.

6.5.37.1 Feature Report
The change sensitivity should be set to 0 for the sleep detector.

6.5.37.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x1F
Sequence number
Status
Delay
Sleep state
Reserved

Figure 102: Sleep Detector Input Report

Sleep state

Indicates the users current sleep state.
0 – hard wake
1 – soft wake
2 – light sleep
3 – deep sleep
4 – unknown
All other values are reserved

6.5.38

Tilt Detector (0x20)

The tilt detector sends a report each time it detects a tilt. The report ID is 0x20.

6.5.38.1 Feature Report
The change sensitivity should be set to 0 for the tilt detector.

6.5.38.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x20
Sequence number
Status
Delay
Tilt LSB
Tilt MSB

Figure 103: Tilt Detector Input Report

Tilt

Indicates that a tilt was detected.

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1 – tilt detected
All other values are reserved

6.5.39

Pocket Detector (0x21)

The pocket detector sends a report each time it detects entry in or exit from a pocket state. The
report ID is 0x21.

6.5.39.1 Feature Report
The change sensitivity should be set to 0 for the pocket detector.

6.5.39.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x21
Sequence number
Status
Delay
Pocket LSB
Pocket MSB

Figure 104: Pocket Detector Input Report

Pocket State

Bit field.
Indicates pocket detector events. A value of 1 means the event
was detected.
Bit 0 – entered in pocket state
Bit 1 – entered out of pocket state
All other bits are reserved

6.5.40

Circle Detector (0x22)

The circle detector sends a report each time it detects a double circle gesture. The report ID is
0x22.

6.5.40.1 Feature Report
The change sensitivity should be set to 0 for the circle detector.

6.5.40.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x22
Sequence number
Status
Delay
Circle LSB
Circle MSB

Figure 105: Circle Detector Input Report

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Circle

Indicates that a circle was detected.
1 – circle gesture detected
All other values are reserved

6.5.41

Heart Rate Monitor (0x23)

The heart rate monitor measures the user’s heart rate. The report ID is 0x23. Heart rate is an
unsigned 16-bit integer reported in beats per minute (bpm).

6.5.41.1 Feature Report
No special remarks.

6.5.41.2 Input Report
Byte
0
1
2
3
4
5

Description
Report ID = 0x23
Sequence number
Status
Delay
Heart rate LSB
Heart rate MSB

Figure 106: Heart Rate Monitor Input Report

6.5.42

ARVR-Stabilized Rotation Vector (0x28)

The ARVR-stabilized rotation vector sensor reports the orientation of the device. Accumulated
errors are corrected while the device is in motion, which limits the appearance of discontinuities
or jumps in data. The format of the rotation vector is a unit quaternion. The Q point is 14. In
addition an estimate of the heading accuracy is reported. The units for the accuracy estimate
are radians. The Q point is 12. The report ID is 0x28.

6.5.42.1 Feature Report
The change sensitivity is applied to the angular difference between two rotation vectors. The
units for change sensitivity are radians. The change sensitivity is unsigned and the Q point is
13.

6.5.42.2 Input Report
Byte
0
1
2
3
4
5
6
7
8

Description
Report ID = 0x28
Sequence number
Status
Delay
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB

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Byte
9
10
11
12
13

Description
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB
Accuracy estimate LSB
Accuracy estimate MSB

Figure 107: ARVR-Stabilized Rotation Vector Input Report

6.5.43

ARVR-Stabilized Game Rotation Vector (0x29)

The ARVR-Stabilized game rotation vector sensor reports the orientation of the device.
Accumulated errors are corrected while the device is in motion, which limits the appearance of
discontinuities or jumps in data. The format of the rotation vector is a unit quaternion. The Q
point is 14. The report ID is 0x29.

6.5.43.1 Feature Report
The change sensitivity is applied to the angular difference between two rotation vectors. The
units for change sensitivity are radians. The change sensitivity is unsigned and the Q point is
13.

6.5.43.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11

Description
Report ID = 0x29
Sequence number
Status
Delay
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB

Figure 108: ARVR-Stabilized Game Rotation Vector Input Report

6.5.44

Gyro-Integrated Rotation Vector (0x2A)

The Gyro-Integrated Rotation Vector sensor reports the absolute orientation of the device as
determined by integrating gyroscope data at every gyroscope sample and correcting to the
more-accurate Rotation Vector periodically. This sensor can support higher data rates than the
more-accurate Rotation Vector can. The format of the output report is a unit quaternion and
calibrated gyroscope data. The Q point of the angular position is 14 and angular velocity is 10.
The report ID is 0x2A.

6.5.44.1 Feature Report
This feature supports neither on-change nor batched operation.

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While this virtual sensor is controlled (via set-feature reports) with report ID 0x2A on the
common control channel, its data is delivered on the “inputGyroRv” SHTP channel, not the
standard input report channels.

6.5.44.2 Input Report
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13

Description
Unit quaternion i component LSB
Unit quaternion i component MSB
Unit quaternion j component LSB
Unit quaternion j component MSB
Unit quaternion k component LSB
Unit quaternion k component MSB
Unit quaternion real component LSB
Unit quaternion real component MSB
Angular velocity x component LSB
Angular velocity x component MSB
Angular velocity y component LSB
Angular velocity y component MSB
Angular velocity z component LSB
Angular velocity z component MSB

Figure 109: Gyro-Integrated Rotation Vector Input Report

Note that this input report *DOES NOT* contain a report ID field. This is the only type of report
delivered on the “inputGyroRV” SHTP channel, so it is omitted to save transmission time.

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Batching

Under SH-2, all input reports on the inputNormal and inputWakeup channels are delivered in
batch format. The batch interval setting in the Common Dynamic Feature Report (6.5.2) dictates
how many microseconds are allowed to elapse between the point in time where a sensor
measurement is obtained and the time that it is provided to the host. A lower value results in
lower data latency but higher system power consumption.
In order to comply with the Android L requirements [3], we separate wakeup sensor data from
non-wakeup sensor data. Any time that a delivery is triggered, we deliver the data from the
wakeup queue first before sending the data from the non-wakeup queue.

7.1

Batch queues

SH-2 maintains two batch queues, one for wake-up sensor data, the other for non-wake-up
sensor data. These are sized independently and do not share memory.
Sensors are configured as wake-up by setting the wake-up bit in the “Feature Flags” field of the
Common Dynamic Feature Report (6.5.2).

7.2

Batch timestamps

In order to balance the needs of transmitting high-frequency data (with low timestamp overhead)
and low-frequency data (with large batch delay values), we combine the sensor report’s 14-bit
delay field with two additional record types: a Base Timestamp Reference and Timestamp
Rebase.
1. A “Base Timestamp Reference” record is inserted at the start of each batch, giving a
shared time reference between the host and the sensor hub.
2. A “Timestamp Rebase” record is inserted to extend the delay for blocks of reports which
are too far from the batch’s Base Timestamp Reference to be represented with the 14-bit
report delay field.
Figure 110 graphically displays the relationship between the various sources of timing data.

Transport
Reference
(e.g. HINT)

Base
Reference

Report

Report

Timestamp
Rebase

Report

Report

Figure 110: Timestamp Dependencies

7.2.1 Base Timestamp Reference (0xFB)
The Base Timestamp Reference provides a delta from the transport-protocol-defined reference
point (the HINT assert for SHTP) and some arbitrary point in time.

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Byte
0
1
2
3
4

Description
Report ID=0xFB
Base Delta LSB: relative to transport-defined reference
point. Signed. Units are 100 microsecond ticks.
Base Delta
Base Delta
Base Delta MSB

Figure 111: Base Timestamp Reference Record

For example, if HINT occurs at some time t and the Base Timestamp Reference record has a
value for delta of 10, the timestamps in a given batch will be relative to t – 1 ms.
The value 0x7FFFFFFF is reserved to indicate that Base Delta exceeded the maximum value
that could be represented in 32 bits.

7.2.2 Timestamp Rebase (0xFA)
The 14-bit delay field of sensor input reports can represent up to 16383 100-microsecond ticks,
or up to 1.64 seconds. Low frequency, batched sensor data can easily span ranges of time on
the order of seconds or minutes. The Timestamp Rebase record is added to the batch’s Base
Timestamp Reference to derive a new base for sensor reports. Note that Rebase Delta is
signed.

Byte
0
1
2
3
4

Description
Report ID=0xFA
Rebase Delta LSB: relative to Base Timestamp
Reference. Signed. Units are 100 microsecond ticks.
Rebase Delta
Rebase Delta
Rebase Delta MSB

Figure 112: Timestamp Rebase Record

For example, if HINT occurs at time 5.0 seconds and the batch’s Base Timestamp Base Delta is
4.0 seconds, this establishes a shared base timestamp at 1.0 seconds. If a timestamp rebase is
encountered having delta 1.5 seconds, then the basis to which subsequent report delays are
applied will be 2.5 (e.g. a sensor report having delay = 1.0 seconds would be timestamped as
occurring at t=3.5).

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References

1. Hillcrest Laboratories, 1000-3535 Sensor Hub Transport Protocol
2. Hillcrest Laboratories, 1000-3600 SH-2 SHTP Reference Manual
3. Batching: http://source.android.com/devices/sensors/batching.html

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Notices

Information furnished by Hillcrest Laboratories, Inc. (Hillcrest) is believed to be accurate and
reliable. However, Hillcrest assumes no responsibility for its use, nor for any infringement of
patents or other rights of third parties that may result from its use.
Hillcrest reserves the right to make changes, corrections, modifications or improvements to this
document at any time without notice. Information in this document supersedes and replaces all
information previously supplied. Hillcrest makes no warranties, express or implied, regarding
the information contained in this document.
Information in this document is provided solely to enable the use of Hillcrest products. “Typical”
and default parameters provided by Hillcrest are not guaranteed, and can vary between
applications and over time.
The product is designed primarily for use in consumer electronics and has not been evaluated
for use in products or systems where failure or malfunction may result in personal injury, death,
severe property damage or environmental damage, such as aerospace, lifesaving, life
sustaining or military applications. Hillcrest assumes no liability for any claims or damages
arising from information contained in this document, or from the use of products and services
detailed herein. This exclusion includes, but is not limited to, claims or damages based on the
infringement of patents, trademarks, copyrights and/or any other intellectual property rights.
The product is provided by Hillcrest “As Is.” Hillcrest makes no representations or warranties
regarding the product express or implied, including without limitation any implied warranties as
to title, noninfringement, merchantability, or fitness for a particular purpose.
Freespace is a registered trademark of Hillcrest Laboratories, Inc. The Hillcrest Labs logo is a
trademark of Hillcrest Laboratories, Inc. All other trademarks and copyrights are the property of
their respective owners.
Third party notices are available on our website at: http://hillcrestlabs.com/legal/third-partyattributions/
Copyright © 2017 Hillcrest Laboratories, Inc. All rights reserved.

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