STM32F7xx —— Timer

作用：输出PWM，测量脉冲长度，定时等。

一、基础定时器配置

// 基本定时器

#define TIMER_CHANNEL             TIM3

#define TIMER_PREEMPT_PRIO        TIM_PRIORITY

#define TIMER_RCC_FUNC            __HAL_RCC_TIM3_CLK_ENABLE

#define TIMER_IRQ                 TIM3_IRQn

#define TIMER_IRQ_FUNC            TIM3_IRQHandler

#define TIMER_DIV                 (10800 - 1)

#define TIMER_PERIOD              (100 - 1)

static TIM_HandleTypeDef timer_handler;     // 定时器操作句柄

// Period：自动重装值。 Prescaler：时钟预分频数

// 定时器溢出时间计算方法:Tout=((Period+1)*(Prescaler+1))/Ft us.

// Ft=定时器工作频率,单位:Mhz

void TimerInit(void)

{

  timer_handler.Instance = TIMER_CHANNEL;

  timer_handler.Init.Prescaler = TIMER_DIV;

  timer_handler.Init.CounterMode = TIM_COUNTERMODE_UP;

  timer_handler.Init.Period = TIMER_PERIOD;

  timer_handler.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

  HAL_TIM_Base_Init(&timer_handler);

  HAL_TIM_Base_Start_IT(&timer_handler);

}

// 定时器底层驱动 开启时钟 设置中断优先级

// 此函数会被 HAL_TIM_Base_Init()函数调用

void HAL_TIM_Base_MspInit(TIM_HandleTypeDef *timer)

{

  TIMER_RCC_FUNC();

  HAL_NVIC_SetPriority(TIMER_IRQ, TIM_PRIORITY, 1);

  HAL_NVIC_EnableIRQ(TIMER_IRQ);

}

void TIMER_IRQ_FUNC(void)

{

  HAL_TIM_IRQHandler(&timer_handler);

}

// 中断服务函数调用

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *timer)

{

  if(timer == (&timer_handler))

  {

     // do something

  }

}

二、带回调定时器

使用回调函数，以链表的方式管理所有的定时器。检测时间到，执行回调函数。TimerRun定时运行，TimerCreate创建一个定时器，TimerStart开启定时器。这里只是写了一个比较简单的定时器，操作系统里面也有类似的定时接口。

#define TIMER_CHANNEL             TIM3

#define TIMER_PREEMPT_PRIO        TIM_PRIORITY

#define TIMER_RCC_FUNC            __HAL_RCC_TIM3_CLK_ENABLE

#define TIMER_IRQ                 TIM3_IRQn

#define TIMER_IRQ_FUNC            TIM3_IRQHandler

#define TIMER_DIV                 (10800 - 1)

#define TIMER_PERIOD              (100 - 1)

static struct

{

  timer_t *next;

} timer_run;

static volatile uint32_t timer_ticks;

static uint32_t timer_ticks_run;

static TIM_HandleTypeDef timer_handler;     // 定时器操作句柄

// Period：自动重装值。 Prescaler：时钟预分频数

// 定时器溢出时间计算方法:Tout=((Period+1)*(Prescaler+1))/Ft us.

// Ft=定时器工作频率,单位:Mhz

void TimerInit(void)

{

  timer_run.next = NULL;

  timer_handler.Instance = TIMER_CHANNEL;

  timer_handler.Init.Prescaler = TIMER_DIV;

  timer_handler.Init.CounterMode = TIM_COUNTERMODE_UP;

  timer_handler.Init.Period = TIMER_PERIOD;

  timer_handler.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

  HAL_TIM_Base_Init(&timer_handler);

  HAL_TIM_Base_Start_IT(&timer_handler);

}

// 定时器底层驱动 开启时钟 设置中断优先级

// 此函数会被 HAL_TIM_Base_Init()函数调用

void HAL_TIM_Base_MspInit(TIM_HandleTypeDef *timer)

{

  TIMER_RCC_FUNC();

  HAL_NVIC_SetPriority(TIMER_IRQ, TIM_PRIORITY, 1);

  HAL_NVIC_EnableIRQ(TIMER_IRQ);

}

void TIMER_IRQ_FUNC(void)

{

  HAL_TIM_IRQHandler(&timer_handler);

}

// 中断服务函数调用

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *timer)

{

  if(timer == (&timer_handler))

  {

    ++timer_ticks;

  }

}

//======================================================================================================

void TimerRun(void)

{

  timer_t *timer;

  timer_t *timer_done;

  timer_done = NULL;

  while(timer_ticks_run != timer_ticks)

  {

    timer = timer_run.next;

    if(timer)

    {

      if(timer->ticks)

      {

        ++timer_ticks_run;

        timer->ticks--;

      }

      // 将后续超时的定时器都移除

      while(timer && (0 == timer->ticks))

      {

        timer_run.next = timer->next;

        timer->next = timer_done;

        timer_done = timer;

        timer = timer_run.next;

      }

    }

    else

    {

      ++timer_ticks_run;

    }

  }

  while(timer_done)

  {

    timer = timer_done;

    timer_done = timer->next;

    timer->next = NULL;

    timer->handler(timer->param);

  }

}

void TimerCreate(timer_t *timer, timer_cb_t handler, void *param)

{

  timer->handler = handler;

  timer->param = param;

}

void TimerStart(timer_t *timer, uint32_t timeout)

{

  timer_t *p;

  uint32_t ticks = (timeout + 9) / 10;

  TimerCancel(timer);

  p = (timer_t *)&timer_run;

  while(p->next)

  {

    if(ticks <= p->next->ticks)

    {

      p->next->ticks -= ticks;

      break;

    }

    else

    {

      ticks -= p->next->ticks;  // ticks 有可能为 0

    }

    p = p->next;

  }

  timer->ticks = ticks;

  timer->next = p->next;

  p->next = timer;

}

void TimerCancel(timer_t *timer)

{

  timer_t *p;

  if(NULL == timer)

  {

    return;

  }

  p = (timer_t *)&timer_run;

  while(p->next)

  {

    if(p->next == timer)

    {

      if(timer->next)

      {

        timer->next->ticks += timer->ticks;

      }

      p->next = timer->next;

      timer->next = NULL;

      break;

    }

    p = p->next;

  }

}

static timer_t timer;

static void handler(void *param)

{

  TimerStart(&timer, 1000);

  printf("TimerStartrn"); 

}

  TimerCreate(&timer, handler, NULL);

  TimerStart(&timer, 1000);

  TimerRun(); // 放在10ms任务中运行