ARM9开发的13个例子源程序，用C语言写的，在mini2440编译通过，包括按钮，LED灯控制，PWM蜂鸣器报警等源代码。,ARM9 development of 13 examples of source code, written using C language, compiled in mini2440 through, including buttons, LED light control, PWM buzzer alarm, such as source code.

PWM控制LED灯渐亮渐灭实验,利用定时器控制产生占空比可变的 PWM 波-PWM control of LED lights getting brighter gradually eliminate experiments, the use of a timer to control the wave of variable duty cycle PWM