说明：  百分表是通过齿轮或杠杆将一般的直线位移（直线运动）转换成指针的旋转运动。现通过串口读取数显百分表实时数据，将数据传输到单片机，单片机根据实时数据驱动步进电机传动丝杆。实时监控最大最小值
(Dial indicator or via a gear lever which is generally linear displacement (linear motion) is converted into rotational movement of the pointer. Now dial indicator reads real-time data through the serial port to transfer data to the microcontroller, the microcontroller drive a stepper motor drive screw according to real-time data. Real-time monitoring of maximum and minimum)