Design of acquisition system for acquiring current output signal based on STM32

Current signals are commonly used as output signals of sensors. For sensors with output signals ranging from 4 to 20mA, a data acquisition system based on STM32F103 microcontroller of ARM Cortex-M3 kernel is proposed in this paper. The experimental results show that the acquisition system can realize the functions of data acquisition, data storage and data display by using the task management mechanism of μC/OS-II operating system, managing the data of SD card with FatFs file system and writing the interface in QT. In addition, the acquisition precision can reach less than 1%. This paper mainly analyzes three aspects of the acquisition system: 1. Hardware, including microcontroller, signal conversion module, data storage module and serial communication module; 2. Software, including ADC acquisition function, data storage function, upper computer display interface and μC/OS-II real-time system; 3. Experiment and result, including precision experiment and application example.