拧动AD旁边的电位器，会在数码管的前三位显示0-255之间的数值。这就是把模拟信号转换成数字信号，即模数转换。-Screw moving next Potentiometers AD will be in the digital control of the top three shows values between 0-255. This is the analog signals into digital signals, that is, analog-digital conversion.