说明：   PWM 控制 LED 灯渐亮渐灭程序 适用 ME300B 开发系统 晶振为11.0592M 利用定时器控制产生占空比可变的 PWM 波 按K1，PWM值增加，则占空比减小,LED 灯渐暗。 按K2，PWM值减小，则占空比增加,LED 灯渐亮。 当PWM值增加到最大值或减小到最小值时，蜂鸣器将报警。
(PWM control of LED lights gradually becoming bright ME300B out procedures applicable to the development of systems for 11.0592M crystal timer to control the use of variable duty cycle generated by the PWM wave K1, PWM value to increase, then decrease the duty cycle, LED lights dimming. By K2, PWM values decrease, then increase the duty cycle, LED lights become bright. When the PWM value to increase or decrease the minimum value, the buzzer will alarm.)