键控流水灯实验，MCU是PIC18F452,实验板式APP001。按下第一个按键实现流水灯正流转，按下第二个按键直接开始流水灯逆流转，再次按下第二个按键流水灯停止。-Keying light water experiments, MCU is the PIC18F452, experimental plate APP001. Press the button to achieve the first flow of water is light, press the button directl