本程序使用C8051F020单片机自带的模数转换器，进行模数转，输出模拟电压。-C8051F020 single chip uses the built-in ADC, the analog-to-digital switch, the output analog voltage.

模拟电压采样，单片机校正后输出数字电压，通过DAC芯片输出校正后的电压(Analog voltage sampling, MCU output digital voltage correction, through the DAC chip output corrected voltage)