PWM 控制LED

extern void delay_ms(u16 nms);
u16 led0pwmval=0;

 

 int main(void)
 {  
 
 //u8 dir=1; 
 delay_init();       //ÑÓʱº¯Êý³õʼ»¯  
 NVIC_Configuration();   //ÉèÖÃNVICÖжϷÖ×é2:2λÇÀÕ¼ÓÅÏȼ¶£¬2λÏìÓ¦ÓÅÏȼ¶
 uart_init(9600);  //´®¿Ú³õʼ»¯Îª9600
  LED_Init();        //LED¶Ë¿Ú³õʼ»¯
  TIM3_PWM_Init(7199,100);  //²»·ÖƵ¡£PWMƵÂÊ=72000000/900=80Khz
    while(1)
 {
//    delay_ms(10); 
//   if(dir)led0pwmval++;
//   else led0pwmval--;

//    if(led0pwmval>300)dir=0;
//   if(led0pwmval==0)dir=1;  
//if(key1==1)
 // if (GPIO_ReadInputDataBit(GPIOC,GPIO_Pin_0)==0)
  if(!(GPIOC->IDR & GPIO_Pin_0))
{ delay_ms(10);
   //if(key1==0)
 //if (GPIO_ReadInputDataBit(GPIOC,GPIO_Pin_0)==0)
 if(!(GPIOC->IDR & GPIO_Pin_0))
    led0pwmval++;
 }
//if(key2==1)
if (GPIO_ReadInputDataBit(GPIOC,GPIO_Pin_1)==0)
{
 delay_ms(10);
 //if(key2==0)
  if (GPIO_ReadInputDataBit(GPIOC,GPIO_Pin_1)==0)
   led0pwmval--;
}
if(led0pwmval>7199)
 led0pwmval=0;
if(led0pwmval<0)
 led0pwmval=0;
  TIM_SetCompare2(TIM3,led0pwmval);  

 } 
 }

void TIM3_Int_Init(u16 arr,u16 psc)
{
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 NVIC_InitTypeDef NVIC_InitStructure;

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //ʱÖÓʹÄÜ

 TIM_TimeBaseStructure.TIM_Period = arr; //ÉèÖÃÔÚÏÂÒ»¸ö¸üÐÂʼþ×°Èë»î¶¯µÄ×Ô¶¯ÖØ×°ÔؼĴæÆ÷ÖÜÆÚµÄÖµ  ¼ÆÊýµ½5000Ϊ500ms
 TIM_TimeBaseStructure.TIM_Prescaler =psc; //ÉèÖÃÓÃÀ´×÷ΪTIMxʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵ  10KhzµÄ¼ÆÊýƵÂÊ 
 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //ÉèÖÃʱÖÓ·Ö¸î:TDTS = Tck_tim
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIMÏòÉϼÆÊýģʽ
 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //¸ù¾ÝTIM_TimeBaseInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯TIMxµÄʱ¼ä»ùÊýµ¥Î»
 
 TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //ʹÄÜÖ¸¶¨µÄTIM3ÖжÏ,ÔÊÐí¸üÐÂÖжÏ

 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM3ÖжÏ
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  //ÏÈÕ¼ÓÅÏȼ¶0¼¶
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //´ÓÓÅÏȼ¶3¼¶
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQͨµÀ±»Ê¹ÄÜ
 NVIC_Init(&NVIC_InitStructure);  //¸ù¾ÝNVIC_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèNVIC¼Ä´æÆ÷

 TIM_Cmd(TIM3, ENABLE);  //ʹÄÜTIMxÍâÉè
       
}
//¶¨Ê±Æ÷3ÖжϷþÎñ³ÌÐò
void TIM3_IRQHandler(void)   //TIM3ÖжÏ
{
 if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //¼ì²éÖ¸¶¨µÄTIMÖжϷ¢ÉúÓë·ñ:TIM ÖжÏÔ´
  {
  TIM_ClearITPendingBit(TIM3, TIM_IT_Update  );  //Çå³ýTIMxµÄÖжϴý´¦Àíλ:TIM ÖжÏÔ´
  LED1=!LED1;
  }
}

 

//TIM3 PWM²¿·Ö³õʼ»¯
//PWMÊä³ö³õʼ»¯
//arr£º×Ô¶¯ÖØ×°Öµ
//psc£ºÊ±ÖÓÔ¤·ÖƵÊý
void TIM3_PWM_Init(u16 arr,u16 psc)
{ 
 GPIO_InitTypeDef GPIO_InitStructure;
 TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 TIM_OCInitTypeDef  TIM_OCInitStructure;
 

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //ʹÄܶ¨Ê±Æ÷3ʱÖÓ
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB  | RCC_APB2Periph_AFIO, ENABLE);  //ʹÄÜGPIOÍâÉèºÍAFIO¸´Óù¦ÄÜÄ£¿éʱÖÓ
 
 GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //Timer3²¿·ÖÖØÓ³Éä  TIM3_CH2->PB5   
 
   //ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM3 CH2µÄPWMÂö³å²¨ÐΠGPIOB.5
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //TIM_CH2
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //¸´ÓÃÍÆÍìÊä³ö
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_Init(GPIOB, &GPIO_InitStructure);//³õʼ»¯GPIO
 
   //³õʼ»¯TIM3
 TIM_TimeBaseStructure.TIM_Period = arr; //ÉèÖÃÔÚÏÂÒ»¸ö¸üÐÂʼþ×°Èë»î¶¯µÄ×Ô¶¯ÖØ×°ÔؼĴæÆ÷ÖÜÆÚµÄÖµ
 TIM_TimeBaseStructure.TIM_Prescaler =psc; //ÉèÖÃÓÃÀ´×÷ΪTIMxʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵ
 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //ÉèÖÃʱÖÓ·Ö¸î:TDTS = Tck_tim
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIMÏòÉϼÆÊýģʽ
 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //¸ù¾ÝTIM_TimeBaseInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯TIMxµÄʱ¼ä»ùÊýµ¥Î»
 
 //³õʼ»¯TIM3 Channel2 PWMģʽ 
 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ2
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
 //TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
 TIM_OC2Init(TIM3, &TIM_OCInitStructure);  //¸ù¾ÝTÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIM3 OC2

 TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);  //ʹÄÜTIM3ÔÚCCR2ÉϵÄԤװÔؼĴæÆ÷
 
 TIM_Cmd(TIM3, ENABLE);  //ʹÄÜTIM3