High-Precision Micro Capacitance Signal Measurement System-Based on Pcap01

Aiming at the problem of weak capacitance signal detection, a high-precision micro capacitance detection system based on Pcap01 chip is designed. The system uses STM32F103 single chip microcomputer as the main control chip. The system hardware is mainly composed of Pcap01 module, STM32 minimum system module, system power supply module and isolation module. The system software mainly includes the C program of the lower computer to realize the collection of micro capacitance data, the communication between Pcap01 and STM32, and the display of measurement data on the upper computer interface. By fitting the relationship between the measured capacitance and the chip output value with the least square algorithm, the error caused by parasitic capacitance of adjacent pins of the chip can be greatly reduced. The experimental results show that the system has the advantages of good linearity and high precision.