采用51单片机外部中断接收同步信号，输出按照选定通道在收到同步信号后输出，并延时一段时间然后终止输出，等待下一下同步信号下降沿来临。另外还有一路PWM占空比可调输出。- Uses 51 monolithic integrated circuit external interrupt receive synchronized signal, outputs according to designated the channel after receiving the synchronized si