User Manual
USER MANUAL V1.05
© 2013 EnOcean | www.enocean.com STM 330 / STM 331 / STM 330C / STM 332U / STM 333U User Manual V1.10 | Page 5/33
STM 330 / STM 331 / STM 330C / STM 332U / STM 333U
2 GENERAL DESCRIPTION
2.1 Basic functionality
The extremely power saving RF transmitter module
STM 33x of EnOcean is optimized for realization of
wireless and maintenance free temperature sensors, or
room operating panels including set point dial and oc-
cupancy button. It requires only a minimum number of
external components and provides an integrated and
calibrated temperature sensor.
Power supply is provided by a small solar cell, an ex-
ternal energy harvester, or an external 3 V backup
battery. An energy storage is installed in order to
bridge periods with no supply from the energy har-
vester. The module provides a user configurable cyclic
wake up.
After wake up, the internal microcontroller reads the status of the temperature sensor and
optional set point dial. A radio telegram will be transmitted in case of a significant change
of measured temperature or set point values or if the external occupancy button is pressed.
In case of no relevant input change, a redundant retransmission signal is sent after a user
configurable number of wake-ups to announce all current values.
In addition to the cyclic wake-up, a wake up can be triggered externally using the input for
the occupancy button or the internal LRN button.
The firmware can be configured to use different EEPs according to the availability set point
dial and occupancy button.
Features with built-in firmware
Pre-installed solar cell
On-board energy storage and charging circuit
On-board LRN button
On-board TX indicator LED
Calibrated internal temperature sensor
Input for external occupancy button and set point dial
Configurable wake-up and transmission cycle
Wake-up via Wake pins or LRN button
Support for humidity sensor module HSM 100
Features accessible via API
Using the Dolphin API library it is possible to write custom firmware for the module.
The API provides:
Integrated 16 MHz 8051 CPU with 32 kB FLASH and 2 kB SRAM
Integrated temperature sensor
Various power down and sleep modes down to typ. 0.2 µA current consumption
Up to 13 configurable I/Os
10 bit ADC, 8 bit DAC