登录验证，实例设计的电压测量功能模块仅为持有密码的使用者提供。电压测量，单片机控制A\D转换器对被测电压信号进行采样及处理，处理的过程及结果显示在LCD上。-Login authentication, the instance of the voltage measuring modules designed only to provide a password to the user. Voltage measurement, microcontroller A \ D converter s