通过定时间定时一秒钟，并测出当前电机的转速，送显示并调整PWM的占控比来调整电机最后控制电机在设定稳定的转速，并通过串行7279显示。-By timing a given time seconds, and measure the current speed of the motor, to send display and adjust the PWM of the total control than the last control motor to adjust the motor speed setting stable, and display through the serial 7279