EnOcean STM300U TRANSCEIVER MODULE User Manual 1

WO98/36395, DE 100 25 561, DE 101 50 128,

WO 2004/051591, DE 103 01 678 A1, DE 10309334,

WO 04/109236, WO 05/096482, WO 02/095707,

US 6,747,573, US 7,019,241

REVISION HISTORY

The following major modifications and improvements have been made to the first version of

this document:

© EnOcean GmbH

All Rights Reserved

This information describes the type of component and shall not be considered as assured characteris-

tics. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications

are subject to change without notice. For the latest product specifications, refer to the EnOcean web-

site: http://www.enocean.com.

As far as patents or other rights of third parties are concerned, liability is only assumed for modules,

not for the described applications, processes and circuits.

government regulations are to be observed.

Packing: Please use the recycling operators known to you.

TABLE OF CONTENT

The extremely power saving RF transmitter

STM 300/C/U (pads on bottom side of PCB!)

ing to the naming of the EO3000I chip to simplify usage of the DOLPHIN API.

The table in section 3.3 shows the translation of hardware pins to a naming that fits the

functionality of the built-in firmware. When writing own firmware based on the DOLPHIN

API please refer to the Dolphin Core Description and use this manual only for information

The encoding input pins have to be left open or connected to GND in correspondence with

the following connection schemes. These settings are checked at every wake-up.

Via CP_0 and CP_1 an internal counter is set which is decreased at every wake-up signal.

Once the counter reaches zero the redundant retransmission signal is sent.

Via the programming interface the configuration area can be modified. This provides a lot

more configuration options. Values set via programming interface override hardware set-

tings! These settings are read after RESET or power-on reset only and not at every wake-

The interface is shown in the figure below:

EnOcean provides EOPX (EnOcean Programmer, a command line program) and Dolphin

Studio (Windows application for chip configuration, programming, and testing) and the

Telegram content seen at programming interface of STM 300x or at DOLPHIN API:

In case a manufacturer code is programmed into the module the module transmits – in-

stead of transmitting a normal telegram – a dedicated teach-in telegram if

Assumptions:

(e.g. ECS 300 solar cell)

These values are calculated values, the accuracy is about +/-20%!

STM 300 is designed for use with an external energy harvester and energy storage.

In order to support a fast start-up and long term operation with no energy supply available

short term storage alone, for faster recharging. As long as the voltage on long term storage

remains below VON, the charge switcher will continuously switch the energy source be-

tween short term and long term storage, trying to ensure continuous device operation. That

is because of the higher resistance and capacitance of long term storage, which would lead

to much too long charging (i.e. non-operative time). In addition short term storage cannot

be charged over this threshold until the voltage on long term storage exceeds VON. Charge

switcher is the PMOS transistor Q1, driven from the STM 300 charge control output CCO

over T1A. To start with, as long as the STM 300 VDD voltage is below the VON threshold,

only the small storage (C1) is filled over D3. Once the threshold is reached, the CCO control

signal goes High, T1B and Q2 are turned on and the long term storage (C2) will be filled

which limits the maximum charging voltage to 3.3 V to avoid damaging long term energy

storage. In case a different voltage limit is required, this device has to be replaced by a

suitable voltage variant. As soon as the voltage on D2 anode or the voltage detector input

exceeds the selected threshold, the voltage detector delivers a High level on its output con-

nected to the T1A emitter. The T1A base is consequently lower polarized than its emitter

and the transistor is turned off. That means Q1 is turned off too — the energy source is

switched off and long term storage is protected.

The selected voltage detector must have a very low quiescent current in the operating

range, and an appropriate threshold voltage, corresponding to the selected long term ener-

gy storage voltage (e.g. threshold nominally 3.2 V for a 3.3 V capacitor). If the selected

threshold is too low, e.g. 3.0 V, a relatively high amount of energy corresponding to a use-

degradation of their capacity and lifetime, an undervoltage protection block is added.

Undervoltage protection is also implemented through Q2. In normal operation, when VDD

reaches the VON threshold, the STM 300 charge control CCO goes high, T1B rapidly dis-

charges C3 to GND and Q2 turns on long term storage. The C3 charge recovers very slowly

for a longer time does C3 have time to recover and finally to turn off Q2 and thus the long

term storage path (over D4) from the STM 300, avoiding deep discharge.

For more details and alternative circuits please refer to application note AN208.

STM 300 provides an output signal at SCO which is suited to control the supply of the sen-

sor circuitry. This helps saving energy as the sensor circuitry is only powered as long as

necessary. In the default configuration SCO provides a HIGH signal 2 ms (delay time) be-

fore the analog inputs are read. Via the programming interface (see 3.8.2) it is possible to

also usable in “Deep Sleep Mode” or “Flywheel Sleep Mode” (via API only). Due to current

minimization there is no internal pull-up or pull-down at the WAKE pins.

logic levels of WAKE0 and / or WAKE1 is changed, STM 300 starts up.

The figure above shows two examples how the WAKE inputs may be used. When the LRN

button is pressed WAKE1 is pulled to GND and a teach-in telegram is transmitted.

sition of the switch.

Several antenna types have been investigated by EnOcean. Please refer to our application