ARM7开发的PWM输出反馈控制电机，采用了PID控制算法，此例中用了LED输出亮度代表电机转速-ARM7 Development PWM output feedback control motor PID control algorithm, in this case using the LED output brightness on behalf of the motor speed

可调PWM波,能够根据根据参数调整PWM的输出(需要改进)-Adjustable PWM wave, according to the PWM output parameter adjustment (improvement)

无人机四面壁障系统，使用超声波模块实现pwm信号输入输出-Unmanned aerial vehicle barrie