In the process of data acquisition, the main task is to sample the current and voltage parameters of the sampling resistor, and perform analog-to-digital conversion by ADC0832. In the system, the P3.5 and P3.6 ports of MCU are connected with the parallel ports of D1 and D0 and CKL port of ADC0832 module respectively. Output signal of sampling resistor is sent to analog input channel CHO of ADC0832 through O/I port for single channel conversion, and chip select enable terminal CS of ADC0832 is generated by P3.7 pin of MCU. The parallel port of D1 and D0 is controlled by P3.5 port of MCU to select the channel.