STM32F103的PWM设置

只看该作者 · 2012-6-6 11:02

我用TIM3输出一个PWM，从PB5输出，但是在示波器上量不到PWM波形，如果从PA3输出，可以量到PWM，请问在PWM时，怎么设置才能让PWM从期望的IO口输出。代码如下：
void pwm_configuration(void)
{
  u16 temp=0x22;
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

  TIM_DeInit(TIM2);
  TIM_TimeBaseStructure.TIM_Period = temp;    TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;       TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = temp / 2;
  TIM_OC4Init(TIM2, &TIM_OCInitStructure);
  TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Enable);
  TIM_ARRPreloadConfig(TIM2, ENABLE);

  TIM_Cmd(TIM2, ENABLE); /* TIM2 enable counter */
}
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

/*GPIOA Configuration: PA.3 =>  pwm output(AF_PP)  */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
}
设置PA3可以正常输出PWM，把IO改为PB5不能正常输出，请教这个输出端口要在哪里设置。

只看该作者 · 2012-6-6 11:36

你使用的TIM2定时器，仔细看看datasheet,
输出引脚的映射 PA3为TIM2_CH4,当然能输出
PB5为TIM3_CH2.

只看该作者 · 2012-6-6 12:04

这个输出引脚的映射可以更改吗

只看该作者 · 2015-12-16 20:03

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) //TIM3ÖÐ¶Ï
{
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);

//ÉèÖÃ¸ÃÒý½ÅÎª¸´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)

//³õÊ¼»¯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);

//³õÊ¼»¯TIM3 Channel2 PWMÄ£Ê½
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

只看该作者 · 2016-3-12 11:11

我也正在秋这个问题，楼主解决了吗

STM32F103的PWM设置

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