Concept and realization of a modular and versatile platform for metal oxide semiconductor gas sensors

Abstract

Abstract To meet the requirements for high quality data capturing of metal oxide semiconductor (MOS) gas sensors, a platform is presented that can handle a large variety of sensors. Besides manufacturer modes, the platform is able to run sensors in temperature cycled operation (TCO). A system concept is presented that provides hardware modules to adapt to different MOS types like analog/digital or thin film/thick film. For analog sensors, an analog frontend with two different power variants handles the different power demands of thick film and thin film sensors. The concept and realization of the analog frontend is shown. For digital sensors, a generalized design with digital signal input sections was developed to receive data via I2C, SPI, or UART. A single microcontroller model constitutes the core of each board variant and it is flashed with a unified firmware which manages the module specific tasks. For continuity and usability, a graphical user interface (GUI) is presented that allows the user to modify measurement parameters and monitor the measurement. GUI and firmware are tuned to one another and exchange data and information to perform user commands. The validation of the accuracy of the analog temperature control is discussed and the successful usage of the system in various applications like indoor air quality (IAQ) is shown.