proteus仿真P0.0口按键控制/P2.0-P2.3输出方波/可驱动步进电机，也可以做为按键控制PWM输出，延时方波，不用定时器和中断(P0.0 port button control /P2.0-P2.3 output square wave / drive stepper motor, can also be used as keys to control PWM output, delay square wave, without timers and interrupts)