单片机源程序如下:
- #include "led.h"
- #include "delay.h"
- #include "key.h"
- #include "sys.h"
- #include "usart.h"
- #include "timer.h"
-
- int main(void)
- {
- u16 led0pwmval=0;
- u8 dir=1;
- delay_init(); //延时函数初始化
- NVIC_Configuration(); //设置NVIC中断分组2:2位抢占优先级,2位响应优先级
- uart_init(9600); //串口初始化为9600
- LED_Init(); //LED端口初始化
- TIM3_PWM_Init(899,0); //不分频。PWM频率=72000/900=80Khz
- while(1)
- {
- delay_ms(10);
- if(dir)led0pwmval++;
- else led0pwmval--;
- if(led0pwmval>300)dir=0;
- if(led0pwmval==0)dir=1;
-
- TIM_SetCompare2(TIM3,led0pwmval);
- }
- }
复制代码
所有资料51hei提供下载:
实验15 PWM输出-LED-直流电机.rar
(292.85 KB, 下载次数: 14)
|