STM32F407的A-B编码器.doc

前几天调了一天编码器，一点反应都没有，放弃了。今天忽然想起没有加上拉电阻，加了两个就ok了。
顺便说一下，f407的编码器接口的配置和f103一模一样，唯一的不同就是f407的tim2和tim5是32位的，而103好像都是16位的。使用32位编码器的话，
在好多时候都可以不使用tim中断。直接读取cnt的值就可以了。

void ENC_Init(void)
{
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;  
  TIM_ICInitTypeDef TIM_ICInitStructure;  
  GPIO_InitTypeDef GPIO_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);

  //GPIO_StructInit(&GPIO_InitStructure);
  /* Configure PC.06,07 as encoder input */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOC, &GPIO_InitStructure);

  GPIO_PinAFConfig(GPIOC,GPIO_PinSource6,GPIO_AF_TIM3);
     GPIO_PinAFConfig(GPIOC,GPIO_PinSource7,GPIO_AF_TIM3);

  /* Enable the TIM3 Update Interrupt */
//  NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
//  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
//  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
//  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
//  NVIC_Init(&NVIC_InitStructure);

  /* Timer configuration in Encoder mode */ 
  //TIM_DeInit(TIM3);
  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);

  TIM_TimeBaseStructure.TIM_Prescaler = 0x0; // No prescaling 
  TIM_TimeBaseStructure.TIM_Period = 60000; 
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;   
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI1, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
  TIM_ICStructInit(&TIM_ICInitStructure);
  TIM_ICInitStructure.TIM_ICFilter = 0;
  TIM_ICInit(TIM3, &TIM_ICInitStructure);

  // Clear all pending interrupts
  TIM_ClearFlag(TIM3, TIM_FLAG_Update);
  TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
  //Reset counter
  //TIM2->CNT = 100;

  // ENC_Clear_Speed_Buffer();

  TIM_Cmd(TIM3, ENABLE); 
}