关键词: STM32；氧化锆；传感器；加热电路；信号调节电路

Abstract: This paper designed an oxygen content measurement module based on STM32F030C8T6, and a ZrO₂ sensor was used as the oxygen content sensing device. Firstly, the basic principle of the sensor is analyzed, and a heating circuit and a constant current source circuit necessary for the sensor are designed based on the sensor principle. Because the output signal of sensor is an mV level Nernst voltage signal, a signal conditioning circuit is designed to simplify the measurement of ZrO₂ sensor. The experiment proves that after the module is calibrated with standard gas, the accuracy of measuring the oxygen content can reach 1%. Through Modbus interface, multiple modules can communicate with the master device, which can be easily applied in industrial control measurement.

Key words: STM32; ZrO₂; sensor; heating circuit; signal conditioning circuit