How to configure STM32 timer to trigger interrupt on every increment/decrement?

Question

I try to interface a rotary encoder with STM32F7. A timer (TIM1) should count a value between 0-100 and trigger an interrupt every time the value is incremented or decremented.

The counting works but I only can configure an interrupt on every update event. (if counter overflows/underflows)

How can I configure such a timer?

static void MX_TIM1_Init(void)
{

  TIM_Encoder_InitTypeDef sConfig;
  TIM_MasterConfigTypeDef sMasterConfig;

  htim1.Instance = TIM1;
  htim1.Init.Prescaler = 0;
  htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim1.Init.Period = 99;
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim1.Init.RepetitionCounter = 0;
  htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  sConfig.EncoderMode = TIM_ENCODERMODE_TI1;
  sConfig.IC1Polarity = TIM_ICPOLARITY_RISING;
  sConfig.IC1Selection = TIM_ICSELECTION_DIRECTTI;
  sConfig.IC1Prescaler = TIM_ICPSC_DIV1;
  sConfig.IC1Filter = 0;
  sConfig.IC2Polarity = TIM_ICPOLARITY_RISING;
  sConfig.IC2Selection = TIM_ICSELECTION_DIRECTTI;
  sConfig.IC2Prescaler = TIM_ICPSC_DIV1;
  sConfig.IC2Filter = 0;
  if (HAL_TIM_Encoder_Init(&htim1, &sConfig) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }

}

Egoruch Egoruch · Accepted Answer · 2020-12-01T14:05:57

You can use Edge Detector Trigger TI1F_ED Example for STM32F030F4P6:

/* Trigger Edge Detector */
/* 100: TI1 Edge Detector (TI1F_ED) */
TIM3->SMCR &= ~(TIM_SMCR_TS_0 | TIM_SMCR_TS_1);
TIM3->SMCR |= TIM_SMCR_TS_2;
/* 1: Trigger interrupt enabled. */
TIM3->DIER |= TIM_DIER_TIE;
NVIC_EnableIRQ(TIM3_IRQn);

void TIM3_IRQHandler(void){
    if(TIM3->SR & TIM_SR_TIF){
        
    /* Here code */
    
        /* Interrupt enabled */
        TIM3->SR &= ~TIM_SR_TIF;
    }
}

More infromation: https://www.youtube.com/watch?v=1CPk9UD4440 https://cxemka.com/71-podklyuchenie-enkodera-dupa-k-stm32-cmsis-i-hal.html

How to configure STM32 timer to trigger interrupt on every increment/decrement?

3 Answers