利用加強式PWM模組輸出半橋式PWM輸出，并設定適當的空乏時間，同時開啟自動關閉的功能，當RB0觸發時蜂鳴器與LED5（P1B），是否運作正常-Type PWM module output to strengthen the use of half-bridge PWM output, and set the appropriate depletion time and automatically turns off the feature turned on, the buzzer is tr