Design and Implementation of a High-Sensitivity Exhaled Breath Analyzer

In this study, a portable exhaled gas analyzer based on STM32 was developed, featuring modular hardware architecture and advanced control strategies. The signal of the gas sensor was collected in real time through the built-in analog-to-digital converter (ADC), and the working temperature of the sensor was maintained with heating circuit. At the software level, the control protocol is designed based on the state machine architecture, and the human-computer interface is realized through the serial display screen. The system processes the data by moving average filtering algorithm, and realizes the accurate calculation and dynamic display of gas concentration. An event-driven mechanism based on state machine is indicatively proposed to coordinate tasks such as data acquisition, protocol analysis, and interface refresh in an orderly manner to achieve efficient and orderly operation of the system.