CubeF1 ADC with DMA, DMA1_Channel1_IRQHandler interrupt is blocked by while() loop?

[calltherain]

Posted on January 30, 2015 at 05:05

Attached is the project files, CubeMX file is also in the package.

I just added some simple code in these 2 places. everything else is generated by CubeMX. main.c, int main(void)

/* USER CODE BEGIN 3 */
/* Infinite loop */
while (1) {
DMATC = 0;
HAL_ADC_Start_DMA(&hadc1, (uint32_t *) adcValues, 5);
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_SET); //for debug
while(DMATC == 0)
{
;
}
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_RESET); //for debug
}
/* USER CODE END 3 */

stm32f1xx_it.c

void DMA1_Channel1_IRQHandler(void)
{
/* USER CODE BEGIN DMA1_Channel1_IRQn 0 */
/* USER CODE END DMA1_Channel1_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_adc1);
/* USER CODE BEGIN DMA1_Channel1_IRQn 1 */
if ( HAL_DMA_GetState( &hdma_adc1 ) == HAL_DMA_STATE_READY )
DMATC = 1;
/* USER CODE END DMA1_Channel1_IRQn 1 */
}

With the above

while(DMATC == 0)

loop in main.c the interrupt handler is never invoked, if I remove the while() loop in main.c then the interrupt is invoked. What am I doing wrong? Maybe I missed some configuration ? Thanks

[calltherain]

Posted on February 01, 2015 at 11:32

I tried not using while(1) to wait the ADC DMA completes, instead, I used a 1Kh timer to start the ADC:

/**
* @brief This function handles TIM1 update interrupt.
*/
void TIM1_UP_IRQHandler(void)
{
/* USER CODE BEGIN TIM1_UP_IRQn 0 */
/* USER CODE END TIM1_UP_IRQn 0 */
HAL_TIM_IRQHandler(&htim1);
/* USER CODE BEGIN TIM1_UP_IRQn 1 */
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_15, GPIO_PIN_SET); //for debug

HAL_ADC_Start_DMA( &hadc1, (uint32_t *)adcValues, 2);

HAL_GPIO_WritePin(GPIOB, GPIO_PIN_15, GPIO_PIN_RESET); //for debug
/* USER CODE END TIM1_UP_IRQn 1 */
}

And I added my own implementation for void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{

HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_SET); //for debug

HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_RESET); //for debug

}

by using a scope I can see that sometimes there is no pulse for PB14, so it seems that the DMA sometimes failed for some reason?

[childresss]

Posted on February 02, 2015 at 04:50

is DMATC a constant? Being upper case, by convention, it's a #defined constant or an unchanging const I/O register or some such.

If DMATC is declared as global variable, is it declared as volatile since the ISR alters it?

[calltherain]

Posted on February 02, 2015 at 16:34

DMATC is a global var declared in main.c,

/* USER CODE BEGIN PV */
__IO uint8_t DMATC;

in stm32f1xx_it.c, it is referenced :

extern __IO uint8_t DMATC;

now I'm using HAL_ADC_PollForConversion to wait the conversion completes because I can specify a timeout value:

HAL_StatusTypeDef HAL_ADC_PollForConversion ( ADC_HandleTypeDef * hadc, uint32_t Timeout )

and seems that it works okay. But I can't figure out why while(1) doesn't work as expected.