刚学stm32f103的板子，就是按照原子的程序改了个IO口，但是好像PA7的没有PWM输出，我也是用TIM3_CH2来控制PA7的灯，毫无反应，灯都不亮，求大神指教void TIM3_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler =psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE );
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_Cmd(TIM3, ENABLE);
}void TIM3_IRQHandler(void) //TIM3ÖжÏ
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update );
}
}
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);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
//ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM3 CH2µÄPWMÂö³å²¨ÐÎ GPIOB.5
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure)
//³õʼ»¯TIM3
TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler =psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
//³õʼ»¯TIM3 Channel2 PWMģʽ
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_Cmd(TIM3, ENABLE);
}
主程序是这样的
int main(void)
{
u16 led0pwmval=0;
u8 dir=1;
delay_init();
JTAG_Set(JTAG_SWD_DISABLE); //¹Ø±ÕJTAG); //¹Ø±ÕJTAG
NVIC_Configuration();
uart_init(9600);
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_SetCompare2(TIM3,led0pwmval);
}
}
才学stm32,求帮忙，弄了好两天了，非常感谢
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