简易电压表是利用模拟量转换成数字量经单片机处理并反映在显示器上，它可以分析5V的电压，并能用该电压表可测出该电路的电流和电阻值。(The simple voltmeter is converted into digital quantity by analog quantity. It is processed by MCU and reflected on the display. It can analyze the voltage of 5V, and can use this voltm