✨ feat:增加背光默认等级

Firmware/Source/Application/BackLight.c

@@ -409,6 +409,6 @@ void BackLight_Process(void)
     }
     else
     {
-        ;
+        TimerM_PWM_set_duty(TIMERM_COUNTER1, TIMERM_CHB, BACK_LIGHT_Val_4);
     }
 }