请问STM32f103使用的是官方库V3.5，使用TIM3产生PWM时，通道4的B1口只能输出方波是怎么回事呀？其他通道都正常呢

樱洛川 · 发表于 2016-3-12 21:39:49

以下是我的程序：首先配置I/O口：

static void TIM3_GPIO_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

/* */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

  /* GPIOA and GPIOB clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

  /*GPIOA Configuration: TIM3 channel 1 and 2 as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;       //复用推挽模式
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /*GPIOB Configuration: TIM3 channel 3 and 4 as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_0 | GPIO_Pin_1;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
}

然后配置定时器：
static void TIM3_Mode_Config(void)
{
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

/* 定义占空比变量 */
u16 pwmaf = 800;
u16 pwmab = 0;
u16 pwmbf = 800;
u16 pwmbb = 0;

  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 999;    //
  TIM_TimeBaseStructure.TIM_Prescaler = 7;       //输出10KHzＰＷＭ
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ; //
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  /* PWM1 Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;       //
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 999;    //设置通道１的占空比，Ａ６口
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  //
  TIM_OC1Init(TIM3, &TIM_OCInitStructure);    //
  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 0;    //设置通道２占空比为０，Ａ７口
  TIM_OC2Init(TIM3, &TIM_OCInitStructure);    //
  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel3 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 800; //设置通道3输出占空比，B0口
  TIM_OC3Init(TIM3, &TIM_OCInitStructure);    //
  TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel4 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 0; //设置通道4输出占空比，B1口
  TIM_OC4Init(TIM3, &TIM_OCInitStructure); //
  TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM3, ENABLE);    //

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);                //
}

A6、A7、B0输出占空比正常，但B1口输出始终为标准方波
请问是因为我哪里配置错了吗？谢谢

樱洛川 · 发表于 2016-3-13 11:08:28

今天再调试的时候发生了这样的现象，我同时开启TIM3和TIM4时，TIM3的通道4输出的占空比为TIM4通道4的给定值，同时TIM4通道4对应的PB9脚没有PWM输出。当关闭TIM4时，TIM3输出PWM恢复正常。也就是说，在两个TIM同时开启的情况下，TIM3的通道4受TIM4的通道4决定。但TIM4通道4对应的PB9脚始终没有PWM输出，请问这是怎么回事呀？感觉好奇怪