Temperature Sensor with EFM Processor and Dual RS232 Interfaces

  • 1495


This module contains a TMP102 Temperature Sensor. The TMP102 is accurate to 0.5°C/0.9°F over a range of -25°C to +85°C (-13°F to 185°F). Some of the other components on the board may not be able to handle that wide of range. Other components, especially the microcontroller, produce heat and can change the temperature at the TMP102 by several degrees.

The pre-programmed firmware keeps the microcontroller in a low power standby mode and turns on periodically to take a measurement. Doing this with a low enough duty cycle reduces the impact of the microcontroller heating the sensor and causing inaccuracies.

The module also contains an EFM32ZG108 Gecko low power microcontroller and two RS232 serial ports allowing it to be daisy chained in a network. Pre-Programmed for use in an openHAB Home Automation system or can be Re-Programmed for other uses. 


  • TMP102 Temperature Sensor
    • 12-bit Resolution
    • Readings to 0.0625°C resolution
    • Very low power
    • -40°C to +125°C Temperature Range
    • Programmable Alert Output
  • +3.6V to +6V Input Voltage
  • Power management designed for very low standby power
  • Small Size: PCB is 20mm x 20mm (0.79" x 0.79")
  • EFM32ZG108 Gecko Microcontroller
    • ARM Cortex-M0+
    • Low Power Operation
    • 32KB Flash Memory
    • 4KB RAM
  • MAX3232 Dual RS232 Line Driver/Receiver
  • Two 4 Pin DF11 Right Angle Male Connectors each with Power and RS232
  • 6 Pin DF11 Right Angle Male Connector for Programming and Debug
  • Pre-Programmed with openHAB Item Firmware for Plug-and-Play
  • Pre-Programmed Firmware is Designed for Low Power Operation
  • May be Programmed with the Arduino IDE


  • Thermostat Controls
  • Battery Management
  • Thermal Protection circuits
  • Environmental Monitoring
  • Home automation


TMP102 RS232x2 Schematic
TMP102 RS232x2 Eagle Files
TMP102 Data Sheet
EFM32ZG108 Data Sheet
EFM32ZG Reference Manual

Arduino IDE Examples:





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