Freescale Semiconductor ZT2 ZStar Triaxial Accelerometer User Manual DRM078

Freescale Semiconductor, Inc. ZStar Triaxial Accelerometer DRM078

manual

freescale.comWireless Sensing Triple Axis Reference design(ZSTAR) Designer Reference ManualZSTARRMRev. 0.98/2006
USA:This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interferenceCanada:This Class [*] digital apparatus complies with Canadian ICES-003.Cet appareil numériqué de la classe [*] est conformé à la norme NMB-003 du Canada.Europe:TBD Warning: Any changes or modifications to this device not expressly approved by the party responsible forcompliance could void the user's authority to operate the equipment.
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 3Wireless Sensing Triple Axis Reference designDesigner Reference Manualby: Pavel Lajšner and Radomír KozubFreescale Czech Systems LaboratoriesRožnov pod Radhoštěm, Czech RepublicTo provide the most up-to-date information, the revision of our documents on the World Wide Web will be the most current. Your printed copy may be an earlier revision. To verify you have the latest information available, refer to:http://www.freescale.comThe following revision history table summarizes changes contained in this document. For your convenience, the page number designators have been linked to the appropriate location.Revision HistoryDate RevisionLevel Description PageNumber(s)May,2006 0.02 First draft N/AJuly2006 0.9 Language correction, minor updates N/A
Revision HistoryWireless Sensing Triple Axis Reference design, Rev. 0.94Freescale Semiconductor
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 5Table of ContentsChapter 1 Introduction1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.2 MMA7260Q 3-axis Accelerometer Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Chapter 2 Wireless Sensing Triple Axis Reference design introduction2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.2 Featured products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.2.1 Triple Axis Accelerometer MMA7260Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.2.2 Microcontroller MC9S08QG8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.2.3 MC13191 2.4 GHz ISM Band Low Power Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.2.4 Microcontroller MCHC908JW32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Chapter 3 Sensor Board description3.1 Board overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153.2 A/D conversion of XYZ levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2.1 ADC module init: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2.2 ADC measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.3 Power management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.3.1 MC13191 power management features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.4 ZSTAR Sensor Board hardware overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.4.1 Analog connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.4.2 g-select connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.4.3 BDM (Background Debug Mode) connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.4.4 Sensor Board schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.4.5 Button connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.4.6 MC13191 to MC9S08QG8 microcontroller interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.4.7 MC13191 RF interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.4.8 Clocking options of MC9S08QG8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.4.9 LED indicators connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.4.10 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253.5 Bill of Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Chapter 4 USB stick board description4.1 Board overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.2 ZSTAR USB stick Board hardware overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.2.1 USB connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.2.2 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.2.2.1 Fixed voltage regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table of ContentsWireless Sensing Triple Axis Reference design, Rev. 0.96Freescale Semiconductor4.2.3 MC13191 to MCHC908JW32 microcontroller interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.2.4 Oscillator and clocking options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.2.5 LED indicators connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.2.6 Button connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324.2.7 MON08 interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324.2.8 Optional serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324.2.9 USB stick schematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334.3 Bill of Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Chapter 5 Software Design5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.2 SMAC (Simple Media Access Controller) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.2.1 SMAC Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.2.2 Modifications of SMAC for ZSTAR demo. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.2.2.1 MC9S08QG8 SMAC modifications (Sensor Board) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2.2.2 MCHC908JW32 SMAC modifications (USB stick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2.2.3 Generic SMAC modifications (USB stick + Sensor Board). . . . . . . . . . . . . . . . . . . . . . . . 375.3 ZSTAR RF protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385.3.1 Zpacket format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385.3.1.1 Network number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.3.1.2 RX strength. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.3.1.3 Zcommand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.3.1.4 Zdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.3.2 ZSTAR protocol Zcommand description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405.3.2.1 ZSTAR_BROADCAST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405.3.2.2 ZSTAR_CONNECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405.3.2.3 ZSTAR_DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405.3.2.4 ZSTAR_ACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.3.2.5 ZSTAR_CALIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.3.2.6 ZSTAR_STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.4 STAR protocol and ZSTAR extensions (over USB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425.4.1 Communication handshake ‘R’ (0x52) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425.4.1.1 Extended Communication handshake ‘r’ (0x72). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425.4.2 Accelerometer data transfer ‘V’ (0x56). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425.4.2.1 Extended Accelerometer data transfer ‘v’ (0x76) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435.4.3 Calibration data ‘K’ (0x4B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435.4.4 Calibration process ‘k’ (0x6B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445.4.4.1 Remaining STAR demo commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445.4.5 Additional ZSTAR commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445.4.5.1 g-select reading ‘G’ (0x47) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445.4.5.2 g-select setting ‘g’ (0x67) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455.4.5.3 Info ‘I’ (0x49). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455.4.5.4 Debug on ‘U’ (0x55) and Debug off ‘u’ (0x75) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455.4.6 Further debug and test commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465.4.6.1 Forced channel number selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465.4.6.2 Semiautomatic self-calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465.5 Bootloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 75.5.1 Bootloading procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485.5.2 Dualboot guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.5.2.1 Dualboot applications switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Chapter 6 Application Setup6.1 ZSTAR Installation Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.1.1 USB stick installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.1.2 AN2295 Bootloader Drivers installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Table of ContentsWireless Sensing Triple Axis Reference design, Rev. 0.98Freescale Semiconductor
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 9Chapter 1 Introduction1.1 IntroductionThis paper describes the design of a Wireless Sensing Triple Axis Reference design (ZSTAR), a demo for wireless demonstration of the 3-axis accelerometer MMA7260Q sensors from Freescale.The reference design will enable you to see how Freescale's accelerometers can add additional functionality to applications in various industries. The accelerometer measurements can be grouped into 6 sensing functions - Fall, Tilt, Motion, Positioning, Shock and Vibration - for multifunctional applications.The RD3152MMA7260Q development tool offers robust wireless communication using the powerful, easy-to-use 2.4GHz frequency MC13191 transceiver. Minor changes can be made with pin to pin compatibility allowing implementation of the MC13192 and MC13193 for ZigBeeTM wireless applications.Figure 1-1 ZSTAR Demo photo (CR2032 batteries for comparison)1.2 MMA7260Q 3-axis Accelerometer SensorThe MMA7260Q low cost capacitive micromachined accelerometer features signal conditioning, a 1-pole low pass filter and temperature compensation, and g-Select, which allows a selection from 4 sensitivities. Zero-g offset full scale span and filter cut-offs are factory set and require no external devices. This device includes a sleep mode making it ideal for handheld battery powered electronics.
IntroductionWireless Sensing Triple Axis Reference design, Rev. 0.910 Freescale Semiconductor
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 11Chapter 2 Wireless Sensing Triple Axis Reference design introduction2.1 IntroductionThe Wireless Sensing Triple Axis Reference design (ZSTAR) has been designed as a wireless complement to the previous STAR (Sensing Triple Axis Reference design) RD3112MMA7260Q demo. A 2.4GHz radio-frequency (RF) link based on the low-cost MC13191 family is used for connection from the sensor to PC, allowing the visualization of key accelerometer applications.Figure 2-1ZSTAR demo overviewThe demo consists of the two boards:• Sensor Board (or remote board) containing the MMA7260Q 3-axis accelerometer, S08 family MC9S08QG8 8-bit microcontroller and the 2.4GHz RF chip MC13191 for wireless communication.• USB stick, again with the MC13191 RF front-end, and the HC08 family MCHC908JW32 for the USB communication.Both sides communicate over the RF medium utilizing the freely available software stack SMAC from Freescale.
Wireless Sensing Triple Axis Reference design introductionWireless Sensing Triple Axis Reference design, Rev. 0.912 Freescale SemiconductorFigure 2-2ZSTAR Block diagram2.2 Featured productsThis demo consist of several Freescale products whose main features are listed below.2.2.1 Triple Axis Accelerometer MMA7260QThe ZSTAR board is a demonstration tool for the MMA7260Q, a 3-Axis Low-g accelerometer. The MMA7260Q has many unique features that make it an ideal solution for many consumer applications, such as freefall protection for laptops and MP3 players, tilt detection for e-compass compensation and mobile phone scrolling, motion detection for handheld games and game controllers, position sensing for g-mice, shock detection for warranty monitors, and vibration for out of balance detection.Features such as low power, low current, and a sleep mode with a quick turn on time, allow the battery life to be extended in end applications. The 3-axis sensing in a small QFN package requires only a 6mm x 6mm board space, with a profile of 1.45mm, allowing for easy integration into many small handheld electronics.There are several other derivatives of the MMA7260Q:•MMA7261Q with a selectable 2.5g to 10g range•MMA6270Q is an XY dual axis accelerometer•MMA6280Q is an XZ dual axis accelerometerAll members of this sensor family are footprint (QFN package) compatible which simplifies evaluation and design of the target application.2.2.2 Microcontroller MC9S08QG8The MC9S08QG8 is a highly integrated member of Freescale’s 8-bit family of microcontrollers based on the high-performance, low-power consumption HCS08 core. Integrating features normally found in larger, more expensive components, the MC9S08QG8 MCU includes a background debugging system and on-chip in-circuit emulation (ICE) with real-time bus capture, providing a single-wire debugging and S08QG8MC13191MMA7260QMC13191HC908JW32
Featured productsWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 13emulation interface. It also features a programmable 16-bit timer/pulse-width modulation (PWM) module (TPM), that is one of the most flexible and cost-effective of its kind.The compact, tightly integrated MC9S08QG8 delivers a versatile combination, from wealth of Freescale peripherals and the advanced features of the HCS08 core, including extended battery life with a maximum performance down to 1.8V, industry-leading Flash and innovative development support. The MC9S08QG8 is an excellent solution for power and size-sensitive applications, such as wireless communications and handheld devices, small appliances, Simple Media Access Controller (SMAC)-based applications and toys.• MC9S08QG8 Features– Up to 20 MHz operating frequencies at >2.1 volts and 16 MHz at <2.1 volts – 8 K Flash and 512 bytes RAM – Support for up to 32 interrupt/reset sources – 8-bit modulo timer module with 8-bit prescaler – Enhanced 8-channel, 10-bit analog-to-digital converter (ADC) – Analog comparator module – Three communication interfaces: SCI, SPI and IIC 2.2.3 MC13191 2.4 GHz ISM Band Low Power TransceiverThe MC13191 is a short range, low power, 2.4 GHz Industrial, Scientific, and Medical (ISM) band transceivers. The MC13191 contains a complete packet data modem which is compliant with the IEEE® 802.15.4 Standard PHY (Physical) layer. This allows the development of proprietary point-to-point and star networks based on the 802.15.4 packet structure and modulation format. For full 802.15.4 compliance, the MC13192 and Freescale 802.15.4 MAC software are required.When combined with an appropriate microcontroller (MCU), the MC13191 provides a cost-effective solution for short-range data links and networks. Interface with the MCU is accomplished using a four wire serial peripheral interface (SPI) connection and an interrupt request output, which allows the use of a variety of processors. The software and processor can be scaled to fit applications ranging from simple point-to-point to star networks.2.2.4 Microcontroller MCHC908JW32The MCHC908JW32 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCU’s). All MCU’s in the family use the enhanced M68HC08 central processor unit (CPU08) and are available in a variety of modules, memory sizes and types, and package types.• MCHC908JW32 Features– Maximum internal bus frequency: 8-MHz at 3.5-5V operating voltage – Oscillators:- 4-MHz crystal oscillator clock input with 32MHz internal phase-lock loop- Internal 88-kHz RC oscillator for timebase wakeup – 32,768 bytes user program FLASH memory with security feature – 1,024 bytes of on-chip RAM – 29 general-purpose input/output (I/O) ports:– 8 keyboard interrupt with internal pull-up- 3 pins with direct LED drive- 2 pins with 10mA current drive for PS/2 connection
Wireless Sensing Triple Axis Reference design introductionWireless Sensing Triple Axis Reference design, Rev. 0.914 Freescale Semiconductor– 16-bit, 2-channel timer interface module (TIM) with selectable input capture, output compare, PWM capability on each channel, and external clock input option – Timebase module– PS/2 clock generator module– Serial Peripheral Interface Module (SPI) – Universal Serial Bus (USB) 2.0 Full Speed functions: - 12 Mbps data rate - Endpoint 0 with an 8-byte transmit buffer and an 8-byte receive buffer - 64 bytes endpoint buffer to share amongst endpoints 1–4
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 15Chapter 3 Sensor Board description3.1 Board overviewThe Sensor Board utilizes a small footprint size dual-layer printed circuit board (PCB) containing all the necessary circuitry for MMA7260Q accelerometer sensing and transferring data over a radio frequency (RF). Figure 3-1Sensor Board overviewThe board is powered by a Lithium coin-sized CR2032 battery with provisions also made for the larger capacity CR2477 size. The block diagram of the board is as follows:Lithium battery on the opposite sideMC13191MC9S08QG8MMA7260QBattery SwitchLED indicatorsPCB antennasBDM interfaceButtons
Sensor Board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.916 Freescale SemiconductorFigure 3-2Sensor board block diagramFigure 3-3 shows in more detail, how different software and hardware modules co-operate with each other. The main task of the Sensor board is to:• periodically wake-up from power saving mode• measure all three XYZ acceleration values from the sensor• compose a data frame using simple ZSTAR RF protocol•use SMAC (Simple Media Access Controller) to send this data frame over the RF link• wait for an acknowledgment from the other end (here, the USB stick)• go to sleepThis basic loop repeats roughly 20 times per second providing nearly a real-time response from the sensor.MMA7260QaccelerometerX Y Z sleep g-selectMC9S08QG8MCUMC131912.4GHz RFreceive antennatransmit antennaSPIIRQCR2032 or CR2477Lithium battery
A/D conversion of XYZ levelsWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 17Figure 3-3ZSTAR Sensor board software overviewFor the Sensor board operation, several of the MC9S08QG8’s hardware modules are used: Analog to Digital Converter (ADC), Synchronous Peripheral Interface (SPI), External Interrupt Request module (IRQ) and General Purpose Input/Output (GPIO).3.2 A/D conversion of XYZ levelsThe 3-axis accelerometer sensor MMA7260Q provides three separate analog levels for the X, Y and Z axis. These outputs are ratiometric which means that the output offset voltage and sensitivity will scale linearly with applied supply voltage. This is a key feature when interfacing to a microcontroller with A/D converter reference levels tied to a power supply, because it provides system level cancellation of supply induced errors in the analog to digital conversion process.During the analog-to-digital conversion in the microcontroller, 8-bit resolution is used. MC9S08QG8 A/D channels 0, 1 and 2 are connected to X (channel 1), Y (channel 2) and Z (channel 0) outputs of the MMA7260Q. The microcontroller’s APCTL1 register enables these ADC channels for pin I/O control by the ADC module. The ADCCFG register controls the selected mode of operation, clock source, clock divide, and configuration for low power or long sample time.3.2.1 ADC module init:APCTL1 = 0b00000111; /* 0,1,2 channels are ADC */ADCCFG = 0b01100000; /* set prescale to 8, ADICLK=BUS, 8-bit, high speed */Actual ADC measurements are done in the main software loop. There is a macro (called POWSUM) that allows configuration of measurement to take several measurements of each channel during one loop. E.g. changing POWSUM to 3, 2^3 = 8, each channel will be measured 8 times, with POWSUM 7, each channel Sensor dataAnalog-to-Digital converter(ADC) moduleMC9S08QG8SMACZSTAR RF protocol handlersleepsoftwarecalibration datag-selectSerial Peripheral Interface (SPI) moduleIRQMC13191MMA7260QGPIO
Sensor Board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.918 Freescale Semiconductoris measured 128 times. By default, POWSUM is 0, for 1 measurement of each channel. Before result values are provided, the accumulated values are scaled back to the 8-bit range and inverted where necessary (may be required depending on the physical MMA7260Q device orientation relative to the Earth gravity).Raw (i.e. not calibrated) values are actually sent, the calibration and calculation of an exact g value is done internally in the PC software.3.2.2 ADC measurementThe following routine is used for accelerometer measurement:unsigned int xx = 0; unsigned int yy = 0;unsigned int zz = 0;unsigned char xxx, yyy, zzz;#define POWSUM 0for (i = 0; i < (1 << POWSUM); i++) {ADCSC1 = 0x01; //read X channelwhile(!ADCSC1_COCO);xx += ADCR;ADCSC1 = 0x02; //read Y channelwhile(!ADCSC1_COCO);yy += ADCR;ADCSC1 = 0x00; //read Z channelwhile(!ADCSC1_COCO);zz += ADCR;}xxx = ~(unsigned char)(xx >> POWSUM);yyy = ~(unsigned char)(yy >> POWSUM);zzz = (unsigned char)(zz >> POWSUM);3.3 Power managementA CR2032 (or CR2477) Lithium battery provides a fairly limited charge for such a realtime-like demo that demands frequent transmissions. Some sort of power management has to be implemented in order to keep the current consumption at a reasonable level. Typically, current consumptions of Sensor board components are as follows:• 2.4GHz transceiver MC13191 – in Hibernate mode, 2.3µA– in Doze mode, 35µA– in Idle mode, 500µA– in Transmit mode, 30mA– in Receive mode, 37mA
Power managementWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 19• 8-bit microcontroller MC9S08QG8 – in Stop mode, 750nA– in Wait mode, 1mA– in Run mode, 3.5mA• low-g triaxial sensor MMA7260Q– in Sleep mode, 3µA– in Normal mode, 500µAIt is obvious that in a battery operated application care must be taken to ensure the lowest possible current consumption, especially when the maximum current (provided by the battery) is somehow limited. A CR2032 Lithium battery cannot provide current in the range of 40mA for long periods of time. To alleviate high current surges, an additional large capacitor has been designed - see 3.4.10 Power supply. For transmission and reception using the MC13191, a specific scheme has been used to ensure the battery is not depleted or overloaded. Targeting a 20 samples per second (50ms period) transmission rate, the following scheme for one transmission/sleep cycle is used for the data transfer:Figure 3-4Transmission/sleep cycle detailsAs shown on the previous diagram, all parts of the Sensor board remain most of the time in Sleep/Doze/Stop modes, in which the total current consumption is below 10µA. During each loop, once the data has been acquired from sensor, transmission over the MC13191 transceiver is initiated. The current consumption of the transmitter is ~30mA at that time, but only for a short period of time (typically ~600µs).In order to keep the sensor board informed on the status of connection (for example, if the data-receiving side - USB stick - is out of range, disconnected, etc.), the reception has to be turned on after the data has been transmitted. This is not really required within each loop cycle, and in the actual implementation only on every 8th loop the receive window opens (receiver is enabled to receive the acknowledgment). More in the 5.3 ZSTAR RF protocol description.timeSleepwake-upNormalMMA7260Q:DozeMC13191:StopMC9S08QG8:StopSleepRun StopSensorstabilizes SensorbeingmeasuredTXWaitWaitRXoptionalreceivewindow NOT TO SCALEDozedatatransmitted
Sensor Board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.920 Freescale SemiconductorThe reception window is larger to fit any incoming receive data and the current consumption is also higher during reception, so this portion of current consumption would be one of the largest if the acknowledgment was received in every loop cycle.The “optional receive” feature allows huge power savings, still keeping the reception of acknowledgment data from the data-receiving side.Some further savings might be incorporated by utilizing the timer-triggered transceiver events that are described in the MC13191 Reference Manual.The MC13191, for example, latches a so-called time-stamp of each received frame. The data-receiving side may read this value and trigger the acknowledgment to be sent at exactly specified time after reception (also, a start of data frame transmission can be programmed as timer-triggered). The sensor board might then narrow its own receive window to perfectly match the expected time of the acknowledgment frame. For the simplicity of code, this has not been implemented in the current version of ZSTAR firmware.3.3.1 MC13191 power management featuresMC13191 provides several power saving modes. One of them is called Doze mode in which the MC13191 crystal oscillator remains active. An internal timer comparator is functional too, providing a power efficient and accurately timed way of waking-up the application after a specified time.This feature is fully utilized within the Sensor board. The microcontroller calculates the time period for which the application should be in power saving mode, then fills in the timer comparator registers in the MC13191, and the microcontroller goes into Stop mode (MC13191 into Doze mode).Once the timer reaches the pre-programmed time (a timer compare occurs), the MC13191’s IRQ signal is asserted which brings the microcontroller out of the Stop mode. There are various scaling possibilities that allow periods from a few µs up to 1073 seconds (~17 minutes) to be programmed, without intervention of the microcontroller.
ZSTAR Sensor Board hardware overviewWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 213.4 ZSTAR Sensor Board hardware overviewThis section describes the Sensor board in terms of the hardware design. The MC9S08QG8 microcontroller drives both the MMA7260Q sensor and the MC13191 RF transceiver.3.4.1 Analog connectionsThe MMA7260Q sensor is connected to AD0, AD1, and AD2 inputs to analog-to-digital converter via RC filters formed by R3, C3, R4, C2, R5, C1. These are recommended to minimize clock noise from the switched capacitor filter circuit inside the sensor. Once the software filtering (also described in 3.2 A/D conversion of XYZ levels) is employed, these RC filters may be completely omitted.3.4.2 g-select connectionsR1, R2, R6 and R7 components are made on the PCB. R1 and R2 are just footprints with no components assembled, while R6 and R7 are connected with copper trace allowing the user to disconnect (cut) these lines. By default, g-sel1 and g-sel2 MMA7260Q sensor input pins (used to select the acceleration range) are connected to pins PTB0 and PTB1 of the microcontroller. The range can be controlled by software.If user does not want to use this feature, the g-range can be selected by placing 0R resistors in the R1 and/or R2 positions. If no resistors are assembled, MMA7260Q internal pull-down resistors will automatically select the 1.5g range (both g-sel inputs low).Once R6 and R7 are cut, PTB0 and PTB1 (or their alternate SCI functionality of RxD1 and TxD1, or KBI or AD inputs) may be used. These signals are also routed to BDM connector, pins 3 and 5.3.4.3 BDM (Background Debug Mode) connectionsA J2 connector is a non-standard footprint primarily intended for in-factory programming and testing via “spring-needle” type of connections. The J2 connector carries all standard signals for Background Debug Mode communication so if required, one may solder wires and a standard 2x3 pins 2.54mm (100mil) pitch header for regular BDM re-programming. The pin numbering is shown on Figure 3-5.Figure 3-5BDM connector layout123456
Wireless Sensing Triple Axis Reference design, Rev. 0.922 Freescale SemiconductorSensor Board description3.4.4 Sensor Board schematicsFigure 3-6Sensor board schematicsG_SEL2/TxDG_SEL1/RxDVDDVDDVDDVDDVDDVDDAGND GNDGNDGND GNDGNDGNDGNDGNDGND GND GND GNDGNDGNDGNDVDDVDDGND GNDGNDGNDMOSISPICLKMOSIG_SEL1/RxDG_SEL2/TxDLED1LED2LED1 LED2SPICLKTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.0Low-cost 2.4GHz Triax BoardFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Monday, January 30, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00239\00239.DSNTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.0Low-cost 2.4GHz Triax BoardFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Monday, January 30, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00239\00239.DSNTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.0Low-cost 2.4GHz Triax BoardFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Monday, January 30, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00239\00239.DSN12Q116MHz NX2520SAQ116MHz NX2520SAR2INFR2INF1SSSSR3 10kR3 10kC1110nFC1110nFC1210nFC1210nFR1INFR1INFR5 10kR5 10kBATT1Battery/Renata CR2032BATT1Battery/Renata CR20321 23 465J2BDMJ2BDMRFIN- 1RFIN+ 2PAO+ 5PAO- 6GPIO48GPIO39GPIO210 GPIO111RST12RXTXEN13ATTN14CLKO15SPICLK16MOSI17MISO18CE19IRQ20VDDD 21VDDINT 22GPIO523GPIO624GPIO725CRYSTAL126CRYSTAL227VDDLO2 28VDDLO1 29VDDVCO 30VBATT 31VDDA 32EPGND36 EPGND37 EPGND38 EPGND39 EPGND40 EPGND41EPGND35EPGND34EPGND33U3 MC13191FCU3 MC13191FCC610nFC610nFC710nFC710nFD2LEDD2LEDL222nHL222nH1SPICLKSPICLKg-Sel11g-Sel22VDD 3VSS4SLEEP12 Z13Y14X15U1 MMA7260QU1 MMA7260QL35.6nHL35.6nHC1100nFC1100nFC5 10nFC5 10nFL122nHL122nHD1LEDD1LEDBATT2Battery/Renata CR2477BATT2Battery/Renata CR24771IRQIRQ1 342S1Alps SKRPS1Alps SKRPL44.7nHL44.7nH1MOSIMOSIR70RR70R1MISOMISO+C14470uF/4V+C14470uF/4VR90RR90RC1310nFC1310nFR60RR60RC96.8pFC96.8pFC3100nFC3100nF134 2S2Alps SKRPS2Alps SKRPR80RR80RPTB4/MISO1 8PTB3/KBI7/AD7/MOSI19PTA4/BKGD/MS/ACMP1O 2Vdd 3PTA0/KBI0/AD0/TPM1CH0/ACMP1+16PTA1/KBI1/AD1/ACMP1-15PTA2/KBI2/AD2/SDA114PTA5/RESET/IRQ/TCLK 1Vss 4PTB7/SCL1/EXTAL 5PTB6/SDA1/XTAL 6PTB5/TPM1CH1/SS1 7PTB1/KBI5/AD5/TxD111 PTB0/KBI4/AD4/RxD112 PTA3/KBI3/AD3/SCL113PTB2/KBI6/AD6/SPSCK110U2MC9S08QG8CDTEU2MC9S08QG8CDTEC86.8pFC86.8pFC2100nFC2100nFC1010nFC1010nFSW1Alps/SSSS811101SW1Alps/SSSS811101R4 10kR4 10kC4 100pFC4 100pF
ZSTAR Sensor Board hardware overviewWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 233.4.5 Button connectionsTwo buttons (S1 and S2) are connected directly to pins PTB6 and PTB7. Both have internal pull-up resistors, but are not part of the Keyboard interrupt module, therefore don’t allow a direct microcontroller wake-up from the Stop modes.3.4.6 MC13191 to MC9S08QG8 microcontroller interfaceIn order to fit all the necessary circuitry onto a 16-pin microcontroller, the full recommended MC13191 interface has had to be reduced. The full interface includes the following connections:• 4-wire Synchronous Peripheral Interface (SPI) connection (MISO, MOSI, SPICLK, CE)• Interrupt Request signal (IRQ)• Attention (ATTN) wake-up signal• Receive/Transmit Enable (RXTXEN) signal• External Reset (RST) signalSPI and IRQ are vital for the communication and configuration ofthe MC13191. SPI is connected to the MC9S08QG8 SPI module (pins PTB4/MISO1, PTB3/MOSI1, PTB2/SPSCK1, and GPIO pin PTB5 for CE). Interrupt Request (IRQ) is connected to the microcontroller IRQ pin sharing its alternate RESET function when BDM communication is active.Attention (ATTN) signal is intended to externally wake-up the MC13191 from Doze and Hibernate modes. Since this feature is not used and exit from the Doze mode is done using a timer compare event, The ATTN pin is not routed to the microcontroller and needs to be connected to Vdd.Receive/Transmit Enable (RXTXEN) signal is used to control transitions to/from receive and transmit modes. Since this can be accomplished just by software programming and/or timer compare events, this connection to the microcontroller may also be omitted, saving an additional pin. RXTXEN is connected to Vdd.External Reset (RST) signal places the transceiver in a complete reset condition (Off mode and power down). Alternative Software reset is also possible and since Off mode (the one with the lowest possible power consumption) is not required too, RST is connected to Vdd too.3.4.7 MC13191 RF interfaceThe RF interface (antennas) were designed with the cost and board size in mind. Among several designs, the PCB layout antennas were in the main consideration (cost). Of several PCB antenna designs available for the 2.4GHz band (F-antenna, dipole, loop), the loop antenna has been selected mainly because of the size required on the PCB.The MC13191 transceiver is designed with separated RF IN (receive) and PA OUT (transmit) paths. To avoid the need for an antenna switch, two separate antennas need to be used. Both ZSTAR boards (USB stick and Sensor Board) use the same antenna layout, there are two antennas on the PCB, just on the opposite sides of the PCB.The antenna is designed as a rectangle, 20x24mm (780x940mils), made of 1.25mm (50mils) wide trace of copper. The corners are rounded with a 3.8mm (150mils) radius.
Sensor Board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.924 Freescale SemiconductorFigure 3-7ZSTAR antenna layoutThe matching is provided by L3 (transmit antenna) and L4 (receive antenna) coils. L1 and L2 coils bias the transmitter output transistors to the VDDA level.The inductors used in this design are from TDK:L3 (5.6nH) MLG1608B5N6DTL4 (4.7nH) MLG1608B4N7STand L1, L2 (22nH) MLG1608B22NJT.3.4.8 Clocking options of MC9S08QG8Due to the availability of accurate timing provided by the MC13191 transceiver, an internal oscillator (ICG) in the MC9S08QG8 is used as the main clock source for the microcontroller. The protocol related timing is derived from MC13191 timers, the microcontroller itself is clocked from an internal oscillator, leaving the oscillator pins as GPIO. This is highly beneficial to the limited pin count microcontroller.3.4.9 LED indicators connectionsThe MC13191 allows extension to the number of general I/O pins by 7 additional GPIO connections. Two of these (GPIO1 and GPIO2) are used for LED indicators. R8 and R9 are their current limiting resistors, and in the actual design orange LED’s are used, with a threshold voltage around 2.0-2.5V.The remaining unused GPIO3-GPIO7 signals are connected to ground, improving the physical PCB layout of the MC13191.
ZSTAR Sensor Board hardware overviewWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 253.4.10 Power supplyThe Sensor board is powered by a Lithium coin-sized battery. The primary choice was the popular CR2032, with a PCB layout provision made for the CR2477 size. This bigger battery holds roughly 4 times more charge (~1000mAh), but it is not as popular as CR2032 size.A surface mounted SMTU series battery holder from RenataTM is placed on the underside of the PCB. The SMTU series holders provide (by mechanical construction) battery reverse protection, so no additional circuitry is required. Slide switch SW1 disconnects the battery from the application when not in use.A large tantalum capacitor (C14, 470µF/4V) improves the response of the power supply to current peaks caused by reception or transmission. Coin-sized Lithium CR2032 batteries are targetted at a maximum continuous discharge current in the range of 3mA. Such a large capacitor helps to supply enough current to the MC13191 during a receive/transmit without significant Vdd voltage drops.
Sensor Board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.926 Freescale Semiconductor3.5 Bill of MaterialsTable 3-1. Sensor board bill of materialsItem Quantity Reference Part Manufacturer Manufacturer order code11 BATT1 battery holder CR2032 Renata SMTU 2032-12 3 C1,C2,C3 100nF TDK C1608JB1H104K3 1 C4 100pF TDK C1608CH1H101J47 C5,C6,C7,C10,C11,C12,C13 10nF TDK C1608CH1E103J5 2 C8,C9 6.8pF TDK C1608CH1H070D6 1 L3 5.6nH TDK MLG1608B5N6DT7 1 L4 4.7nH TDK MLG1608B4N7ST82 D1,D2 Kingbright KP-1608SEC Kingbright KP-1608SEC 9 1 J2 BDM + serial N/A10 2 L1,L2 22nH TDK MLG1608B22NJT11 1 Q1 16MHz NX2520SA NDK NX2520SA 16MHz EXS00A-02940Specification n° EXS10B-0722812 2 R1,R2 N/A N/A13 3 R3,R4,R5 10k resistor 0603 package14 2 R6,R7 N/A N/A15 2 R8,R9 0R resistor 0603 package16 1 SW1 slide switch Alps/SSSS811101 Alps SSSS811101(or SKRPACE010 or SKRPABE010)17 2 S1,S2 switch SKRP Alps SKRPADE010(or SKRPACE010 or SKRPABE010)18 1 U1 MMA7260Q Freescale MMA7260Q (MMA7260QR2 for tape and reel)19 1 U2 MC9S08QG8CDTE Freescale MC9S08QG8CDTE20 1 U3 MC13191FC Freescale MC13191FC(MC13191FCR2 for tape and reel)21 1 C14 470uF/4V Vishay 594D477X9004C2T
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 27Chapter 4 USB stick board description4.1 Board overviewThe USB stick board utilizes the same small footprint as Sensor Board is also a dual-layer printed circuit board (PCB). It contains the minimalistic design of the MC13191 RF transceiver connected through an 8-bit MCHC908JW32 microcontroller to the USB. It’s main task is to receive data from the Sensor Board and transfer it to the PC over the USB link.Figure 4-1USB stick board overviewThe USB stick board is powered from the USB. The block diagram of the board is as follows:MC13191MCHC908JW32LED indicatorsPCB antennasUSB “A” type plugButton
USB stick board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.928 Freescale SemiconductorFigure 4-2USB stick board block diagramFigure 4-3 shows, in more detail, how different software and hardware modules co-operate with each other. There are two main tasks of the USB stick board:• receive the data from the MC13191 transceiver and store it in RAM buffer• handle the USB module communication, decode and provide the data from the RAM bufferThese two are somewhat independent and the only common point between them is the accelerometer and button data buffer in RAM. The RF software communicates with the Sensor Board and retrieves the latest accelerometer data. This is stored in RAM and can be independently read by the PC application via the USB link. The protocol employed on the PC side is just a subset of the simple STAR protocol used in the original RD3112MMA7260Q demo. The protocol is described in chapter 5.4 STAR protocol and ZSTAR extensions (over USB).MCHC908JW32MCUMC131912.4GHz RFreceive antennatransmit antennaSPIIRQATTNRSTRXTXENUSB+5V USB voltageregulators+5V USB
Board overviewWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 29Figure 4-3ZSTAR USB stick board software overviewFor the USB stick board operation, several MCHC908JW32 hardware modules are used: USB 2.0 Full-speed module (USB), Synchronous Peripheral Interface (SPI), Keyboard Interrupt module (KBI) and a General Purpose Input/Output (GPIO).SMAClow-level USBSensor & Button dataUSB connection to PCUSB protocolZSTAR RF protocol handlerMCHC908JW32USB 2.0 “virtual serial port” softwareSerial Peripheral Interface (SPI) module KBI GPIO Full Speed moduleMC13191protocol driveror mousehandlersimple STARprotocol handler
USB stick board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.930 Freescale Semiconductor4.2 ZSTAR USB stick Board hardware overviewThis section describes the USB stick board in terms of the hardware design. The MCHC908JW32 microcontroller drives the MC13191 RF transceiver and communicates over USB with PC.4.2.1 USB connectionsTwo USB communication lines are connected directly via R1 to PTE2/D+ and R2 to PTE3/D- microcontroller pins. There, the R1 and R2 resistors define the output impedance of both drivers (ZDRV as per chapter 7 of the USB 2.0 specifications).Terminating the D+ line with a 1.5kΩ pull-up resistor (required for Full-speed signalling) is internal in the MCHC908JW32.A USB “A” type SMT Plug is designed at the edge of the USB stick board allowing the stick to be connected directly into a USB hub without the need for a cable.4.2.2 Power supplyThe USB stick board is a Low-power Bus-powered Function (as defined in chapter 7.2.1.3 of USB 2.0 specifications). This means that a maximum of one unit load (100mA) may be drawn by the USB Stick board. Ferrite beads are included on the VBUS and GND USB connections to minimize EMI. The recommended type is a GLF1608T100M or similar from TDK.VBUS voltage is defined as a minimum 4.4V and a maximum 5.25V on a Low-power Bus-powered Function. The MC13191 RF transceiver requires a maximum power supply voltage of 3.4V and the MCHC908JW32 microcontroller could not guarantee an internal 3.3V regulator working at such a low power supply. Therefore, two separate voltage regulators need to be implemented, and in addition, the voltage levels have to be close enough to avoid the need for level shifters (for the MC13191 to MCHC908JW32 microcontroller interface).4.2.2.1 Fixed voltage regulatorsTwo voltage levels (3.3V for MC13191 and 3.6V for MCHC908JW32) were selected. For these levels, a low-cost, small footprint fixed regulator exists. The NCP502/A series regulators from ON SemiconductorTM were successfully implemented. The NCP502/A series voltage regulator is an 80mA CMOS fixed linear regulator designed primarily for handheld communication equipment and portable battery powered applications which require a low quiescent current.Each device contains a voltage reference unit, an error amplifier, a PMOS power transistor, resistors for setting the output voltage, current limit, and temperature limit protection circuits. The NCP502/A has been designed to be used with low cost ceramic capacitors. The device is housed in a micro-miniature SC70-5 surface mount package. Standard voltage versions are 1.5 V, 1.8 V, 2.5 V, 2.7 V, 2.8 V, 3.0 V, 3.3 V, 3.5 V, 3.6 V and 5.0 V. Other voltages are available in 100 mV steps.Typically, a low-cost 1µF ceramic capacitor is recommended for input and output decoupling. 0603-sized SMD TDK capacitor C1608X5R1A105K was used.
ZSTAR USB stick Board hardware overviewWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 31Enable Operation - Enable pin of 3.3V regulator (for MC13191) is connected to PTC3 pin of the microcontroller. This way, the microcontroller may completely turn off the RF part of the application to minimize power consumption in USB suspend modes.Alternatively, power down of the MC13191 RF transceiver may be done by forcing it into Off mode by pulling the RST pin low.4.2.3 MC13191 to MCHC908JW32 microcontroller interfaceOn the USB stick board the full recommended MC13191 interface has been used. This includes the following connections:• 4-wire Synchronous Peripheral Interface (SPI) connection (MISO, MOSI, SPICLK, CE)• Interrupt Request signal (IRQ)• Attention (ATTN) wake-up signal• Receive/Transmit Enable (RXTXEN) signal• External Reset (RST) signalThe SPI connection is connected to the MCHC908JW32 SPI module signals (MISO, MOSI, SPCLK, SS). The IRQ signal is routed to the PTA3/KBA3 Keyboard interrupt module pin instead of the MCHC908JW32 IRQ pin, which is left for the MON08 interface and the Button connection. The reason for re-routing this signal is that VTST (1.5xVDD, up to 8V) is applied to the microcontroller’s IRQ during programming, therefore some additional jumper configuration would be required to disconnect this voltage fromthe MC13191. Here, the IRQ‘s MON08 function is only shared with the button under the condition that the button is not pressed during programming.The remaining three signals (ATTN, RXTXEN and RST) are connected to GPIO signals of port D (PTD0, PTD2 and PTD1).4.2.4 Oscillator and clocking optionsThe MCHC908JW32 microcontroller requires a stable clock, mainly for the Full-speed USB module operations. USB specifications define an overall 2500ppm (0.25%) accuracy. Basically, any generic 4MHz crystal is sufficient for such accuracy. The main issue with 4MHz crystals are their physical size. Due to the nature of crystal resonating elements, the 4MHz crystals are simply far too big for the USB stick in the ZSTAR demo.Another option is a SAW resonator (e.g. CERALOCKTM series from Murata). These are usually sorted and selected by the manufacturer to fit the USB 2.0 Full-speed accuracy required. Today, only 6, 12, 24 and 48MHz versions are available from Murata. A 6MHz version (manufacturer order code CSTCR6M00G15) has been used in the USB stick design, although the 6MHz frequency is outside the MCHC908JW32 microcontroller specifications.Provision is also made on the PCB (Q3 component) for an Epson SG-310 series (or compatible) Crystal Oscillator (active output). Here, a 4MHz version oscillator is contained in a small 3.2x2.5mm package.4.2.5 LED indicators connectionsThe MCHC908JW32 microcontroller allows a direct drive of LED’s on its three pins. PTB0, PTB1 and PTB5 are high-current open-drain outputs, so the LED’s D1, D2 and D3 are connected to these high-current outputs.
USB stick board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.932 Freescale Semiconductor4.2.6 Button connectionOne button is implemented on the USB stick board. It is connected to the IRQ microcontroller pin that has internal pull-up and allows an easy software interrupt.4.2.7 MON08 interfaceFor MCHC908JW32 in-circuit programming, a MON08 interface is required. Several pins must be connected to specific voltage levels in order for the MCHC908JW32 to enter the Monitor mode. The details are described in the MCHC908JW32 datasheet, Chapter 7 Monitor ROM (MON).To minimize the number of MON08 connections, several pins are hardwired to specific voltage levels directly on the USB stick board. Namely, PTA1 to Vdd, PTA2 and PTC1 to GND. Pins PTA0, RST, IRQ and OSC1, together with the power supply lines, are routed to PCB pads MON08 connector (J3).There is no standard physical connector to be soldered onto the J3 footprint. The J3 connector pads are used during manufacturing for the initial in-circuit programming. Further re-programming of the USB stick maybe done using an AN2295 Bootloader as described in chapter 5.5.4.2.8 Optional serial interfaceFor the purpose of evaluating the USB functions of the MCHC908JW32 microcontroller, a few other pins were routed to an additional PCB pads connector (J2). The two TIM timer pins are connected to J2 allowing emulation of SCI, IIC or such like serial interfaces in software. A simple example of a USB to UART converter software is a part of the AN3153 Application note - Using the Full-Speed USB Module on the MCHC908JW32.
Wireless Sensing Triple Axis Reference design, Rev. 0.933 Freescale SemiconductorUSB stick board description4.2.9 USB stick schematicsFigure 4-4USB stick schematics5544332211DCBATxDRxDPTA0RxDOSC1MIRQMRESETMIRQMRESETMIRQOSC1PTA0GNDVDD36GNDVDD33GNDGNDGND GNDGNDGNDVDDGNDVDD36GNDVDDAGNDGNDGNDVDDGNDGNDVDD36GNDGNDVDD33GNDVDD36GNDGNDGNDGNDVDDVDDVDDGNDGNDVDDGNDGNDGNDVDD36GNDIRQVREG33ENVREG33ENIRQTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.1ZSTAR USB dongleFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Tuesday, August 08, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00240\00240.DSNTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.1ZSTAR USB dongleFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Tuesday, August 08, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00240\00240.DSNTitleSizeDesign Name:RevModify Date: Sheet ofSchematic Name:Copyright FreescalePOPI Status:Author:1.1ZSTAR USB dongleFreescale Semiconductor RCSC1. maje 1009756 61 Roznov p.R., Czech Republic, EuropeA411Tuesday, August 08, 2006SCHEMATIC1General Business InformationRadomir Kozub & Pavel Lajsner2005X:\ICONN\IC108 - LOW-COST 2.4GHZ AND XYZ ACCELEROMETER DEMO\HW\00240\00240.DSNC86.8pFC86.8pFC7100pFC7100pFL64.7nHL64.7nHR3 560R3 560ATTNATTN1C110nFC110nFU4NCP502SQ36T1GU4NCP502SQ36T1GVin1Vout 5GND2Enable3SPCLKSPCLK1L55.6nHL55.6nHR71MR71MC131uFC131uFS1Alps SKRPS1Alps SKRP1 342Q2Murata CSTCR6M00G53Q2Murata CSTCR6M00G5312L322nHL322nHR2 33RR2 33RU2MC68HC908JW32FCU2MC68HC908JW32FCPTA0/KBA01NC 2NC 3PTC1/TCLK1 4PTC3 5PTB56PTC0/T1CH0 7PTE7/SS 8PTE6/MISO 9PTE5/MOSI 10PTE4/SPCLK 11NC 12PTD0 13PTD1 14PTD2 15PTD3 16PTD4 17PTD5 18PTD6 19NC21PTD7 22NC23NC24OSC125OSC226PTB027PTB128VSS3329PTE2/PS2CLK/D+ 30PTE3/D- 31REG33V 32VSSPLL33CGMXFC34VDDPLL 35PTA7/KBA736RESET37IRQ38PTA6/KBA639 PTA5/KBA540PTC2/T1CH1 41VDD 42REG25V 43VSS44PTA4/KBA445 PTA3/KBA346 PTA2/KBA247 PTA1/KBA148NC 20EPGND100 EPGND101 EPGND102 EPGND103 EPGND104 EPGND105 EPGND106 EPGND107 EPGND108C4100pFC4100pFMOSIMOSI1D1LEDD1LEDC111uFC111uFC102n2C102n2FB1BEADFB1BEAD12J3uMON08J3uMON081 23 465D3LEDD3LEDRTXENRTXEN1L422nHL422nHOSC.Q3EPSON-SG310 4.0MHzOSC.Q3EPSON-SG310 4.0MHz32 41D2LEDD2LEDU1MC13191FCU1MC13191FCRFIN- 1RFIN+ 2PAO+ 5PAO- 6GPIO48GPIO39GPIO210 GPIO111RST12RXTXEN13ATTN14CLKO15SPICLK16MOSI17MISO18CE19IRQ20VDDD 21VDDINT 22GPIO523GPIO624GPIO725CRYSTAL126CRYSTAL227VDDLO2 28VDDLO1 29VDDVCO 30VBATT 31VDDA 32EPGND36 EPGND37 EPGND38 EPGND39 EPGND40 EPGND41EPGND35EPGND34EPGND33R1 33RR1 33RSSSS1J1USB-A-MALEJ1USB-A-MALE2134C310nFC310nFQ116MHz NX2520SAQ116MHz NX2520SA1234R5 560R5 560IRQIRQ1R61kR61kC121uFC121uFFB2BEADFB2BEAD12R4 560R4 560C610nFC610nFC210nFC210nFU3NCP502SQ33T1GU3NCP502SQ33T1GVin1Vout 5GND2Enable3J2SerialJ2Serial1 23 465RSTRST1C96.8pFC96.8pFMISOMISO1C510nFC510nF
USB stick board descriptionWireless Sensing Triple Axis Reference design, Rev. 0.934 Freescale Semiconductor4.3 Bill of MaterialsTable 4-1USB stick bIll of materialsItem Quantity Reference Part Manufacturer Manufacturer order code1 5 C1,C2,C3,C5,C6 10nF TDK C1608CH1E103J2 2 C4,C7 100pF TDK C1608CH1H101J3 2 C8,C9 6.8pF TDK C1608CH1H070D4 1 C10 2n2 TDK C1608CH1H222J5 3 C11,C12,C13 1uF TDK C1608JB1C105K6 3 D1,D2,D3 Kingbright KP-1608SEC Kingbright KP-1608SEC 7 2 FB1,FB2 Ferrite bead TDK GLF1608T100M8 1 J1 USB-A-MALE Molex 48037-100091 J2 Serial N/A10 2 L3,L4 22nH TDK MLG1608B22NJT11 1 L6 4.7nH TDK MLG1608B4N7ST12 1 L5 5.6nH TDK MLG1608B5N6DT13 1 Q1 16MHz NX2520SA NDK NX2520SA 16MHz EXS00A-02940Specification n° EXS10B-0722814 1 Q2 Murata CSTCR6M00G15 Murata CSTCR6M00G1515 2 R1,R2 33R resistor 0603 package16 3 R3,R4,R5 560R resistor 0603 package17 1 R6 1k resistor 0603 package18 1 R7 1M resistor 0603 package19 1 U1 MC13191FC Freescale MC13191FC20 1 U2 MCHC908JW32FC Freescale MCHC908JW32FC21 1 U3 NCP502SQ33T1G ON Semi NCP502SQ33T1G22 1 U4 NCP502SQ36T1G ON Semi NCP502SQ36T1G23 1 S1 switch SKRP Alps SKRPADE010 (or SKRPACE010 or SKRPABE010)
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 35Chapter 5 Software Design5.1 IntroductionThis section describes the design of the ZSTAR software blocks. The software description comprises these topics:•SMAC (Simple Media Access Controller) modifications description•‘Air’ ZSTAR RF protocol protocol description• Serial STAR protocol and ZSTAR extensions (over USB) protocol description• AN2295 Bootloader (over USB) implementation notes5.2 SMAC (Simple Media Access Controller)The SMAC is a simple ANSI C based code stack available as sample source code which can be used to develop proprietary RF transceiver applications using the MC13191.5.2.1 SMAC Features• Compact footprint:– 2K FLASH– 10 bytes (+ maximum packet length) RAM– As low as 16kHz bus clock• Can be used to demonstrate coin cell operation for a remote control• MC13191 compatible• Very-low power, proprietary, bi-directional RF communication link• ANSI C source code targeted at the HCS08 core and portable to almost any CPU core (including 4-bit)• Low priority IRQ• Sample application included, extremely easy to use• Liberally commented• Metrowerks CodeWarrior Experimental edition for support5.2.2 Modifications of SMAC for ZSTAR demoThe development of the ZSTAR software is based on the free SMAC stack available from Freescale. The SMAC version used was 4.1a. Two sorts of modifications were made since the original version did not support the HC08 family or the MC9S08QG8 derivative of the 9S08 family. All changes are made using conditional compile options, using ZSTARQG8 and ZSTARJW32 definitions.A fully detailed description of the SMAC is in the SMAC Reference Manual (SMACRM.pdf), available together with SMAC source code.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.936 Freescale Semiconductor5.2.2.1 MC9S08QG8 SMAC modifications (Sensor Board)Here the modifications of the SMAC are very minimal, since the core, peripherals and naming conventions are the same as in the MC9S08GB/GT code (originally in the SMAC 4.1a code).The main changes are listed below:drivers.c:•void MC13192Wake (void) function not implemented, ATTN pin not connected to the microcontroller.•void RTXENDeAssert(void) and void RTXENAssert(void) functions not implemented, RXTXEN pin not connected to the microcontroller.mcu_hw_config.c:• A set of functions void SetGPIO(unsigned char gpio); void ClearGPIO(unsigned char gpio);void ToggleGPIO(unsigned char gpio);added for the purpose of driving LED’s connected to the MC13191 GPIO pins.•void UseExternalClock(void) and void UseMcuClock(void) functions not implemented, no external clock available to the microcontroller.• RESET pin handling in void MC13192Restart(void) and void MC13192ContReset(void) functions omitted since the RESET pin is not connected to the microcontroller.• RESET, ATTN and RXTXEN pins handling in void GPIOInit(void) and void MCUInit(void) functions omitted since these pins are not connected to the microcontroller.• LED toggling added into void MCUInit(void) during the waiting for MC13191 to initialize.device_header.h:• Several SPI, TPM and SOPT definitions added at the top of the standard <mc9s08qg8.h> header file.created port_config_ZSTARQG8.h file with target specific defines (GPIO assignments, etc.)5.2.2.2 MCHC908JW32 SMAC modifications (USB stick)There are several modifications of SMAC required to 1. compile for the HC08 family member MCHC908JW322. reflect that the MC13191 connects to the microcontroller in a slightly different way (as described in chapter 4.2.3 MC13191 to MCHC908JW32 microcontroller interface) - namely, MC13191’s IRQ pin.The 9S08 to HC908 porting required slight changes in the following files:mcu_spi_config.c:•void SPIInit(void) function modified to initialize the HC908 SPI module.mcu_spi_config.h:•SPIWaitTransferDone(), SPIClearRecieveStatReg(), SPIClearRecieveDataReg(), SPISendChar(u8Char) and SPIRead() macros changed to work with the HC908 SPI module.
SMAC (Simple Media Access Controller)Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 37Further changes are relevant to the ZSTAR JW32 platform and specific connections:drivers.h:•CLEAR_IRQ_FLAG macro changed to reflect KBI module serving IRQ requests from MC13191.mcu_hw_config.c:•void UseExternalClock(void) and void UseMcuClock(void) functions no implemented, no external clock available to the microcontroller.• LED toggling added into void MCUInit(void) during waiting for MC13191 to initialize.•UINT8 IRQPinLow(void) function returns the state of the pin PTA3/KBI3 instead of the IRQ pin.mcu_hw_config.h:•IRQFLAG, IRQACK(), IRQInit() and IRQPinEnable() macros changed to reflect KBI module serving IRQ requests from the MC13191.device_header.h:• Several KBI definitions added at the top of the standard <mc68hc908jw32.h> header file.created port_config_ZSTARJW32.h file with target specific defines (GPIO assignments, etc.)5.2.2.3 Generic SMAC modifications (USB stick + Sensor Board)Several modifications of SMAC have been made in order to improve the behavior with some older MC13191 silicon versions. Namely a software time-out functions (using microcontroller’s TIM/TPM timer functions) have been added into UINT8 PDDataRequest(tTxPacket *psPacket)and UINT8 PLMEEnergyDetect (void) functions in simple_phy.c file. Both functions wait for the gu8RTxMode variable to change to IDLE_MODE. This variable should change in the void interrupt IRQIsr(void) function once the execution of a specified task (in MC13191) finishes. Under some rare circumstances, an IRQ event (and also an IRQIsr() interrupt) does not occur, so this software workaround has been implemented to avoid a software lock-up.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.938 Freescale Semiconductor5.3 ZSTAR RF protocolThe ZSTAR demo uses very simple protocol to transfer the accelerometer, button and calibration data between the Sensor Board and the USB stick over the RF medium. The protocol is built on top of SMAC (Simple Media Access Controller) drivers that are available for the MC13191 transceivers family. The protocol is bidirectional allowing the set up of independent connections amongst numerous pairs of ZSTAR demos.All data is transferred in so-called Zpackets. This protocol is primarily targeted at simple demo purposes, allowing a fast transfer of the accelerometer data in short packets with minimum overheads and with minimum battery loads (most of the receive windows eliminated, short transmit packets, etc.).5.3.1 Zpacket formatThe ZSTAR Zpacket is contained inside the MC13191 standard packet structure, which is consistent with the IEEE 802.15.4 Standard. The SMAC library transparently adds a 16 bit Packet control field (see chapter 7.2.1.1 of IEEE 802.15.4 Standard specifications) to differentiate packets from ZigBee and other standards.The Zpacket becomes a payload data for the SMAC standard packet and contains the following fields:•Network number•RX strength•Zcommand•ZdataFigure 5-1Zpacket formatPreamble SFD FLI Payload Data FCSMC13191 Packet Structure SFD (Start of Frame Delimiter)FLI (Frame Length Indicator)FCS (Frame Check Sequence)Network number RXstrength Zcommand ZdataZSTAR Zpacket StructurePacket control SMAC payloadSMAC Packet Structurefield
ZSTAR RF protocolWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 395.3.1.1 Network numberThe network number is randomly generated at the beginning of the connection between the USB stick and the Sensor Board. It is used to determine between various connections. Packets with different Network numbers are simply ignored.This field is 16 bits long.5.3.1.2 RX strengthThis field reports the strength of the last received packet on the other end of the connection. This value simply tells us how well the other side receives ‘our packets’. This can be used by transmission power management functions to change the transmission power if the other party receives packets with enough strength.The values reported are retrieved using the MLMELinkQuality() SMAC primitive.This field is 8 bits long.5.3.1.3 ZcommandThe ZSTAR demo protocol uses a few simple commands to establish and maintain the data flow between the Sensor Board and USB stick. The command is carried in Zcommand field and is 8 bits long. The commands are defined as listed in Table 5-1.5.3.1.4 ZdataThe Zdata field follows the Zcommand field and may be empty if the actual command doesn’t require any additional data. The data format is dependent on the Zcommand. A detailed description is in the next chapter.Table 5-1ZSTAR Zcommand ListZCommand ZCommand code Direction ZdataZSTAR_BROADCAST ‘B’ (0x42) USB stick to Sensor Board noneZSTAR_ACK ‘A’ {0x41) USB stick to Sensor Board noneZSTAR_CALIB ‘K’ (0x4B) USB stick to Sensor Board calibration data to Sensor BoardZSTAR_STATUS ‘S’ (0x53) USB stick to Sensor Board g-range selection data to Sensor BoardZSTAR_CONNECT ‘C’ (0x43) Sensor Board to USB stick calibration data from Sensor BoardZSTAR_DATA ‘D’ (0x44) Sensor Board to USB stickaccelerometer values,button levels,g-range selection
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.940 Freescale Semiconductor5.3.2 ZSTAR protocol Zcommand description5.3.2.1 ZSTAR_BROADCASTThis command is sent when the USB stick tries to establish connection with the Sensor Board. The USB stick first generates a new random network number which is then ‘broadcast’ to any Sensor Board that is not yet connected to a USB stick. The USB stick transmits this command on a free channel, while the Sensor Board searches all available channels. Once a Sensor Board receives this command, it responds with a ZSTAR_CONNECT.5.3.2.2 ZSTAR_CONNECTThis command is a reply to ZSTAR_BROADCAST, ZSTAR_CALIB or ZSTAR_STATUS commands sent by the USB stick. The Zdata field contains the calibration data stored in the Sensor Board, in the following format:Figure 5-2ZSTAR_CONNECT Zdata format5.3.2.3 ZSTAR_DATAOnce the connection is established, the Sensor Board starts to periodically transmit accelerometer, button and g-range status data towards the USB stick.The Zdata field contains 4 bytes; the actual X, Y and Z accelerometer values and a byte with status information. Figure 5-3ZSTAR_DATA Zdata formatEach transmission of a ZSTAR_DATA packet is acknowledged by a ZSTAR_ACK packet from the USB stick, although the Sensor Board does not always open the reception window to receive this acknowledgement, in order to save the battery charge.Xvalue (0g) Xvalue (1g) Yvalue (0g) Yvalue (1g) Zvalue (0g) Zvalue (1g)012 345Zdata bytes:Xvalue Yvalue Zvalue Status012 3msb lsbButton1Button2unusedg-range015-276bits:Zdata bytes:
ZSTAR RF protocolWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 415.3.2.4 ZSTAR_ACKThis command is sent as the data acknowledgement so the Sensor Board board knows that the connection is still alive. If the receive window is opened by the Sensor Board and the ZSTAR_ACK has not been received, the operation (periodic transmission of a ZSTAR_DATA packet) continues but the Sensor Board will try to receive an acknowledgement more frequently. If the acknowledgement is not received several times, the connection is dropped and the Sensor Board will try to re-establish the connection again. The USB stick will recognize this situation once several ZSTAR_DATA packets have not been received.5.3.2.5 ZSTAR_CALIBThis command carries the calibration data provided by the USB stick for the Sensor Board and is sent instead of a ZSTAR_ACK packet. The calibration data is intended to be stored in Flash memory of the Sensor Board. Since the Sensor Board does not receive after every ZSTAR_DATA packet, the USB stick keeps sending a ZSTAR_CALIB until the Sensor Board confirms reception using a new ZSTAR_CONNECT packet.5.3.2.6 ZSTAR_STATUSThis command carries the g-range data provided by the USB stick for the Sensor Board and is sent instead of a ZSTAR_ACK packet. The g-range data is intended to switch the g-range of accelerometer sensor. Since the Sensor Board does not receive after every ZSTAR_DATA packet, the USB stick keeps sending a ZSTAR_STATUS until the Sensor Board confirms reception using a new ZSTAR_CONNECT packet.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.942 Freescale Semiconductor5.4 STAR protocol and ZSTAR extensions (over USB)The ZSTAR demo uses a subset of the original STAR demo protocol commands. This way, most of the software originally developed for the RD3112 (STAR) is also usable with the ZSTAR.The STAR demo communicates over the RS232 serial line with a simple text-based protocol. The same protocol is used in ZSTAR for communication between the USB stick and a PC (over a virtual serial port). The PC application sees the same interface (serial port) and the same protocol as if a STAR demo was connected.5.4.1 Communication handshake ‘R’ (0x52)Initially, a handshake (commands needed to test/establish the connection between the PC and the ZSTAR demo) is conducted. This is accomplished by the PC sending an ‘R’ command, the ZSTAR demo responding with ‘N’. In this way, the PC application sees that the demo is ready for communication. Communication is reset, and any debug or system modes are disabled.Figure 5-4Communication handshake ‘R’ (0x52)5.4.1.1 Extended Communication handshake ‘r’ (0x72)To determine whether a ZSTAR or STAR demo is connected, Only the ZSTAR demo implements an Extended Handshake Communiation command. Once the PC sends the ‘r’ command, the ZSTAR demo responds with a ‘Z’.Figure 5-5Extended Communication handshake ‘r’ (0x72)5.4.2 Accelerometer data transfer ‘V’ (0x56)The PC sends the Values ‘V’ command, the demo responds with 6 bytes in the following sequence:'x', X-value, 'y', Y-value, 'z', Z-value, simply an ‘x’ character followed by the actual X-axis accelerometer binary value, then a ‘y’ followed by the actual Y-axis accelerometer binary value and a ‘z’ followed by the actual Z-axis accelerometer binary value. Since the ZSTAR demo caches the last (over the air) transmitted values, these values are immediately provided to the PC.PC to demodemo to PC‘R’‘N’PC to demodemo to PC‘r’‘Z’
STAR protocol and ZSTAR extensions (over USB)Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 43Figure 5-6Accelerometer data transfer ‘V’ (0x56)5.4.2.1 Extended Accelerometer data transfer ‘v’ (0x76)The ZSTAR demo has also two buttons designed on the Sensor Board. To acquire the actual state of these buttons, the original ‘V’ command has been extended to a ‘v’ command, that provides the same information, followed by a ‘b’ character and a binary byte containing the actual state. The least two significant bits are used, the others are reserved. If a button is pressed, the actual bit is set to ‘1’, and if depressed, the bit is ‘0’.Figure 5-7Extended Accelerometer data transfer ‘v’ (0x76)5.4.3 Calibration data ‘K’ (0x4B)The calibration data is the accelerometer values for specific g (acceleration) levels. The values for 0g and 1g (Earth gravity) are provided for each axis. The values are stored in the Flash memory of the Sensor Board and are transferred to the USB stick once the air connection is established (as described in chapter 5.3.2.2 ZSTAR_CONNECT). These values are stored in the USB stick for retrieval by the PC using the ‘K’ command.The PC sends the Calibration data ‘K’ command, the demo responds with 9 bytes in the following sequence:'X', Xval0, Xval1, 'Y', Yval0, Yval1, Z', Zval0, Zval1, simply an ‘X’ character followed by the 0g and 1g X-axis calibration accelerometer binary values, and the same for Y- and Z-axis.PC to demodemo to PCX-axis value‘x’ Y-axis value‘y’ Z-axis value‘z’‘V’PC to demodemo to PCX-axis value‘x’‘v’Y-axis value‘y’ Z-axis value‘z’ buttons‘b’
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.944 Freescale SemiconductorFigure 5-8Calibration data ‘K’ (0x4B)5.4.4 Calibration process ‘k’ (0x6B)The calibration process is initiated by a ‘k’ command from the PC, followed by 6 bytes of calibration data. These are to be stored in the Flash memory of the Sensor Board being used. More in chapter 5.3.2.5 ZSTAR_CALIB.The calibration data is just 6 bytes in the following sequence:Xval0, Xval1, Yval0, Yval1, Zval0, Zval1 - 0g and 1g calibration accelerometer binary values for X-, Y- and Z-axis. No response from the demo is provided. Verification of the calibration data stored can be done using the Calibration data ‘K’ (0x4B) command.Figure 5-9Calibration process ‘k’ (0x6B)5.4.4.1 Remaining STAR demo commandsThe remaining STAR commands, such as 'F', 'G', 'H', '0', '1', '2', '3' and 'E' are not implemented in the ZSTAR demo.5.4.5 Additional ZSTAR commands5.4.5.1 g-select reading ‘G’ (0x47)The ZSTAR demo allows dynamic selection of the g-range for the accelerometer sensor (see details in chapter 3.4.2 g-select connections), thus additional commands are implemented to read and change the g-range.When the PC issues a ‘G’ command, the ZSTAR demo responds with the g-range actually selected. A ‘0’, ‘1’, ‘2’ or ‘3’ character is returned where ‘0’ is for the 1.5g range, ‘1’ for 2.0g , ‘2’ for 4.0g and ‘3’ for the 6.0g range. If a different sensor (e.g. MMA7261Q) is implemented on the Sensor Board, the g-ranges are 2.5g, 3.3g, 6.7g and 10g respectively.PC to demodemo to PCx(0g)‘X’ ‘Y’ ‘Z’‘K’x(1g) y(0g) y(1g) z(0g) z(1g)PC to demodemo to PCx(0g)‘k’ x(1g) y(0g) y(1g) z(0g) z(1g)
STAR protocol and ZSTAR extensions (over USB)Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 45Figure 5-10g-select reading ‘G’ (0x47)5.4.5.2 g-select setting ‘g’ (0x67)To select the g-range of the sensor on the ZSTAR Sensor Board, a ‘g’ command is issued. It needs to be followed by the required g-range (‘0’, ‘1’, ‘2’ or ‘3’). The USB stick board then communicates this selection to the Sensor Board over the air (see more in 5.3.2.6 ZSTAR_STATUS).No response from the demo is provided. To verify which g-range has been selected, the g-select reading ‘G’ (0x47) command can be used.Figure 5-11g-select setting ‘g’ (0x67)5.4.5.3 Info ‘I’ (0x49)The Info command ‘I’ has only been added to determine which version, compile date, and author of the USB stick software has been implemented. The demo returns a plain text information, and this command is usually issued over terminal (e.g. HyperTerminal) software.Figure 5-12Info ‘I’ (0x49)5.4.5.4 Debug on ‘U’ (0x55) and Debug off ‘u’ (0x75)Various debug information can be observed after issuing a ‘U’ command, usually in terminal (e.g. HyperTerminal) software. Mainly, information on the air protocol is displayed in text, information on the detected channel energy during the surveying for a free channel is shown, channel numbers, and, once the connection is established, the network number. The received level of packets from the Sensor Board PC to demodemo to PC‘G’g-select valuePC to demodemo to PC‘g’ g-select valuePC to demodemo to PC‘I’info text, version, date, etc.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.946 Freescale Semiconductorand the reported USB stick packet level are shown, as well as command names, etc. This can be useful in determining the communication range between the USB stick and the Sensor Board.The debug information is no longer displayed after issuing a ‘u’ command or Communication handshake ‘R’ (0x52).Figure 5-13Debug on ‘U’ (0x55) and Debug off ‘u’ (0x75)5.4.6 Further debug and test commands5.4.6.1 Forced channel number selectionIn order to allow effective testing and debugging, few additional commands have been added. If, before a connection between the USB stick and Sensor Board is established, any hexadecimal number command (‘0’ through ‘9’ or ‘A’ through ‘F’) is sent, the connection will be established on this specific channel number (0 to 15). Any new channel can be selected, sending the new channel number command. The selection becomes effective during the new connection is being established.The return to the automatic mode (where a random channel with the minimum energy is selected) can be forced only by a complete software reset (ie. removing the USB stick from the USB slot).5.4.6.2 Semiautomatic self-calibrationFor the purpose of easier semiautomatic calibration of the ZSTAR demo, additional Calibration command ‘Q’ (0x51) has been added. This command is usually issued over terminal (e.g. HyperTerminal) software.A user is required to place the Sensor Board into 3 specific positions, in which the Earth gravity will induce a maximum acceleration in each of X, Y, and Z axes. Before issuing the first ‘Q’ command, the Sensor Board must be placed flat, ie. with Z-axis aiming toward the Earth core. For the second issue of ‘Q’ calibration command, the board’s X-axis has to aim toward the Earth core. The board should ‘stay’ on its right edge. Next, the Y-axis is calibrated, with the board ‘staying’ on its top edge. Finally, after issuing the fourth ‘Q’ command, the calibration data are sent to the Sensor Board, actually using ZSTAR_CALIB command. The text help is provided during the self-calibration process.PC to demodemo to PC‘U’various debug information‘u’no debug info mainly on air protocol
BootloaderWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 475.5 BootloaderThere’s bootloader software implemented in MCHC908JW32 microcontroller. The bootloader is based on AN2295 Application note - Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs and AN2295SW accompanied software. The original AN2295 bootloader targets serial connections between the PC and applications, and since the MCHC908JW32 implements a virtual serial port application, the USB version of the AN2295 bootloader has been created to allow reprogramming of Flash memory in the USB stick.The USB virtual serial port software is fully described in AN3153 Application note - Using the Full-Speed USB Module on the MCHC908JW32; the MCHC908JW32 bootloader implements the same virtual serial port but under a different PID (the PC sees that serial port as a different application from ZSTAR).The bootloader drivers installation guide can be found in chapter 6.1.2 AN2295 Bootloader Drivers installation.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.948 Freescale Semiconductor5.5.1 Bootloading procedure1. Find on the installation CD the folder with binaries:2. Start (double-click) the CMD.EXE shortcut, a command line window should appear:
BootloaderWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 493. Now type: hc08sprg [bootloader com port number] [binary (S file) that you want to bootload], just like this:hc08sprg.exe com8 accelerometer_v2_ZSTARJW32-new-DUALBOOT.S194. Press ENTER and initial bootloader communication will start:If this screen does not appear, remove the USB stick and start from the beginning.
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.950 Freescale Semiconductor5. Just confirm with Y, and the binary will be loaded onto the USB stick:The bootloader disappears (in Device Manager) and the newly loaded software starts to execute.Using this procedure the software in the USB stick can be changed anytime.
BootloaderWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 515.5.2 Dualboot guidelinesNOTE: The USB stick already comes from factory with two dualboot-aware applications pre-programmed.USB stick and AN2295 Bootloader software provide a way of having two different software (devices) in one USB stick. In order to do this, two dualboot-aware versions of the software needs to be consecutively bootloaded onto the USB stick:Follow the sequence of instructions in the 5.5.1 Bootloading procedure for two dualboot versions of software:1. First bootload accelerometer_v2_ZSTARJW32-new-DUALBOOT.S19.After bootloading, ZSTAR Triaxial Demo (COM1) should appear in Device Manager.2. Next, remove the USB stick again, press the button, re-insert the stick and bootload HID_ZSTARJW32-DUALBOOT.S19 software in.After bootloading, a new device (ZSTAR Triaxial Mouse) should appear:The ‘tilt’ mouse will install automatically and also appear in the Device Manager:
Software DesignWireless Sensing Triple Axis Reference design, Rev. 0.952 Freescale Semiconductor5.5.2.1 Dualboot applications switchingHaving both dualboot-aware applications programmed in the USB stick, they can be switched just by quickly pressing the button (having the USB stick inserted into the USB slot). The applications will appear and disappear accordingly.The ‘tilt’ mouse application in order to work must have sensor board calibrated correctly (e.g. using RD3152MMA7260Q_SW.exe or 5.4.6.2 Semiautomatic self-calibration procedure).
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 53Chapter 6 Application Setup6.1 ZSTAR Installation Procedure6.1.1 USB stick installationFirst of the all, we have to install the USB stick to your PC. Please follow the next steps.1. Plug the USB stick into a USB slot.The ‘Found New Hardware’ announcement should appear:
Application SetupWireless Sensing Triple Axis Reference design, Rev. 0.954 Freescale Semiconductor2. Then the installation wizard starts for new hardware. Choose “Install from a list or special location“
ZSTAR Installation ProcedureWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 553. Point to the Installation CD as the driver path:
Application SetupWireless Sensing Triple Axis Reference design, Rev. 0.956 Freescale Semiconductor4. Installation should continue:
ZSTAR Installation ProcedureWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 575. If you are using Windows XP SP2, you will be asked to stop or continue installation because the drivers are not certified by Microsoft. Select the “Continue Anyway” button6. Installation should succesfully finish.
Application SetupWireless Sensing Triple Axis Reference design, Rev. 0.958 Freescale Semiconductor7. Check whether a new serial port (ZSTAR Triaxial Demo) has appeared in your Device Manager (My Computer, right click, Manage, Device Manager):8. If required, the ZSTAR Triaxial Demo COM port maybe renumbered using the standard procedure in Windows operating system:Right click for Properties, Port Settings tab, Advanced button and change the COM port number accordingly.
ZSTAR Installation ProcedureWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 599. Launch the RD3152 software “RD3152MMA7260QSW.exe" and select the COM port number which you may have assigned in Device Manager.Figure 6-1If no error message appears, the COM port is opened correctly and software communicates with the USB stick.10. Now lets go and check data from the ZSTAR Sensor Board.Raw data, 2D/3D screen, or Scope work should be used for this purpose. While moving (turning, shaking) with a ZSTAR Sensor Board, data from the separate axis should change accordingly.The RD3152MMA7260QSW calibration screen can be used for sensor calibration (calibration data is stored in the Sensor Board).
Application SetupWireless Sensing Triple Axis Reference design, Rev. 0.960 Freescale Semiconductor6.1.2 AN2295 Bootloader Drivers installationThis procedure assumes that ZSTAR Demo drivers are already installed. The drivers are alse common for the bootloader (= are already present in Windows folders). If not, the procedure will be identical to the ZSTAR drivers installation.1. Press the Button on the USB stick and insert it into a USB connector (keeping the button pressed when inserted).The following window appears:
ZSTAR Installation ProcedureWireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 612. The PC searches for an appropriate driver (as the ZSTAR Demo, in some instances a folder with drivers (zstar.inf and usbser.sys) needs to be selected), then the following window should appear:3. Just click Yes, and the bootloader port will be installed (as seen in the Device manager):4. Right click My computer on the Desktop > Properties, Hardware tab, Device Manager button.
Application SetupWireless Sensing Triple Axis Reference design, Rev. 0.962 Freescale Semiconductor5. A similar setup should be observed:6. Note down the COM port number (here, COM8); this is the port number of the BootloaderOnce the software in the USB stick needs to be updated, the Bootloader can be invoked anytime, just by pressing the button while inserting the USB stick into the USB slot.
Wireless Sensing Triple Axis Reference design, Rev. 0.9Freescale Semiconductor 63Appendix AReferencesThe following documents can be found on the Freescale web site: http://www.freescale.com. 1. AN2295 Application note - Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs2. AN3153 Application note - Using the Full-Speed USB Module on the MCHC908JW323. MC9S08QG8 Datasheet4. MCHC908JW32 Datasheet5. MMA7260Q Datasheet6. MC13191 Datasheet
Wireless Sensing Triple Axis Reference design, Rev. 0.964 Freescale Semiconductor
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