HW timers with FreeRTOS

[serefatakan]

Hi,

I am struggling with HW timers when using FreeRTOS. Using H743ZI Nucleo Board and writing on FreeRTOS application examples.

I have changed ThreadCreation application a little bit: created another task that initializes LEDs and a timer, and creates other 2 tasks.

In the modified application, I have tried to setup a timer to get interrupts in every 4 us that only blinks an LED. None of LEDs were blinking and when debugging paused, system goes Default_Handler.

If I comment out timer part, FreeRTOS and tasks works fine; if osKernelStart() line is commented out, timer and interrupt works fine. But I need both so any help will be magnificent.

Here is some part of code:

int main(void)
{
  /* Enable the CPU Cache */
  CPU_CACHE_Enable();
 
 
  HAL_Init();
 
  /* Configure the system clock to 400 MHz */
  SystemClock_Config();
 
  /* Init thread definition */
  osThreadDef(INIT, Init_Thread, osPriorityNormal, 0, configMINIMAL_STACK_SIZE);
  
  /* Start thread 1 */
  InitThreadHandle = osThreadCreate(osThread(INIT), NULL);
 
  /* Start scheduler */
  osKernelStart();
 
  /* We should never get here as control is now taken by the scheduler */
  for (;;);
 
}

And initialization thread (Other threads are same as example):

static void Init_Thread(void const *argument)
{
	TIM_HandleTypeDef    TimHandle;
	uint8_t asdf;
 
	/* Initialize LEDs */
	BSP_LED_Init(LED1);
	BSP_LED_Init(LED2);
 
	__HAL_RCC_TIM3_CLK_ENABLE();
 
	TimHandle.Instance = TIM3;
 
	TimHandle.Init.Period            = 560;
	TimHandle.Init.Prescaler         = 1;
	TimHandle.Init.ClockDivision     = 0;
	TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
	TimHandle.Init.RepetitionCounter = 0;
	TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
 
	/* TIM13 interrupt Init */
	HAL_NVIC_SetPriority(TIM3_IRQn, 0, 0);
	HAL_NVIC_EnableIRQ(TIM3_IRQn);
 
	asdf = HAL_TIM_Base_Init(&TimHandle);
	configASSERT(!asdf);
 
	/*##-2- Start the TIM Base generation in interrupt mode ####################*/
	/* Start Channel1 */
	asdf = HAL_TIM_Base_Start_IT(&TimHandle);
	configASSERT(!asdf);
 
	/* Thread 1 definition */
	osThreadDef(LED1, LED_Thread1, osPriorityNormal, 0, configMINIMAL_STACK_SIZE);
 
	/*  Thread 2 definition */
	osThreadDef(LED2, LED_Thread2, osPriorityNormal, 0, configMINIMAL_STACK_SIZE);
 
	/* Start thread 1 */
	LEDThread1Handle = osThreadCreate(osThread(LED1), NULL);
 
	/* Start thread 2 */
	LEDThread2Handle = osThreadCreate(osThread(LED2), NULL);
 
	for(;;) osThreadTerminate(NULL);
}

And the IRQHandler:

static void TIM3_IRQHandler(void)
{
	BSP_LED_Toggle(LED3);
}

[Tesla DeLorean]

Unless your IRQ Handler clears the source it is going to be re-entering indefinitely.

[serefatakan]

Hi Clive, thank you for reply.

What do you mean by clearing sources? Is the problem about timer initialization? Can you show me an example?

[Chris1 · Accepted solution]

Minimally, since you have enabled the TIM Update event:

static void TIM3_IRQHandler(void)
{
    __HAL_TIM_CLEAR_IT(&TimHandle, TIM_IT_UPDATE);   
                       // clear TIM interrupt pending bit
    BSP_LED_Toggle(LED3);
}

[serefatakan]

Thank you both, my inattention.