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- 2018-5-16
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我把stm32f1的TIM3 ch4通道完全重映射到pc9(LED0)上输出pwm波实现呼吸灯,但是实际效果只是灯一直亮,没有呼吸的效果,说明了并没有输出pwm波到led上,找问题找了很久没解决于是来贴吧寻求帮助。代码如下:
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);//¿aÆô¶¨ê±Æ÷3ê±Öó
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO,ENABLE);//¿aÆôio¿úê±Öóoí¸′óÃ1|Äüê±Öó
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3,ENABLE);//¶¨ê±Æ÷íêè«ó3éäTIM3 CH4 -->PC9
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//íÆíì¸′óÃêä3ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC,&GPIO_InitStructure);//3õê¼»ˉPC9
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//ÏòéϼÆêy
TIM_TimeBaseStructure.TIM_Period = arr;//éèÖÃÔ¤×°ÔØÖμ
TIM_TimeBaseStructure.TIM_Prescaler = psc;//éèÖÃÔ¤·ÖÆμÏμêy
TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);//3õê¼»ˉ¶¨ê±Æ÷
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//êä3öÄ£ê½ÎaPWM1
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;//êä3ö¼«DÔμí
TIM_OCInitStructure.TIM_OutputState = TIM_OutputNState_Enable;//êä3öê1Äü
TIM_OC4Init(TIM3,&TIM_OCInitStructure);//3õê¼»ˉ¶¨ê±Æ÷3í¨μà4
TIM_OC4PreloadConfig(TIM3,TIM_OCPreload_Enable);//ê1Äü¼Ä′æÆ÷Ô¤×°ÔØ
TIM_Cmd(TIM3,ENABLE);//ê1Äü¶¨ê±Æ÷
}
int main(void)
{
u8 key,dir=1;
u16 led0pwmval=0;
delay_init();
key_init();
led_init();
TIM3_PWM_Init(899,0);
while(1)
{
delay_ms(10);
if(dir)led0pwmval++;
else led0pwmval--;
if(led0pwmval>300)dir=0;
if(led0pwmval==0)dir=1;
TIM_SetCompare4(TIM3,led0pwmval);
}
}
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最佳答案
查看完整内容[请看2#楼]
可能是以下两种情况:
1.输出PWM的频率太高导致看不出等闪烁。
2.TIM_OCInitStructure.TIM_OutputState = TIM_OutputNState_Enable;
这句代码开启的TIM_OutputNState_Enable;不知道啥意思,换成TIM_OutputState_Enable;试试吧。
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