用单片机控制一个普通灯泡的亮度，一路开关控制普通灯泡电源的通断，另外两路开关分别控制普通灯泡亮度的增加和减小。-MCU control the brightness of an ordinary light bulb, all the way to switch on and off to control the power of ordinary light bulbs, and other two-way switch control the ordinary bulb brightness