Miniature low cost electrochemical sensor module for measurement of gas concentration

This paper describes miniature low cost sensor module for measurement of gas concentration. The aim of this paper is to explain how to make a miniature module with low power consumption and low cost, which can be used for many types of electrochemical gas sensors without major hardware changes. Device is based on AVR ATmega8 microcontroller. As signal processing circuit a specialized integrated circuit LMP91000 configurable via I2C interface is used. All parameters are saved in EEPROM memory. For communication with master device RS-485 interface is used. In application, after power up, sensor device reads parameters from memory and configure the circuit for signal processing, than the sensor is ready to sends data upon master device request. Master device can change any parameter at any time. The designed sensor module costs less than 10 Euros and consumption less than 4 mA, which is in the idle mode is reduced to about 1mA.