Peeyush Pashine

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8 years ago.

For ST Nucleo F103RB, does it always use external trigger for ADC?

For ST Nucleo F103RB, does it always use external trigger for ADC? Is any timer configured for this? I see a part of code is not present to convert external trigger to regular software channal in F103RB compared to F401RE

In stm321xx_hal_adc.c HAL_ADC_start() it is:

 if (ADC_IS_SOFTWARE_START_REGULAR(hadc)      &&
        ADC_NONMULTIMODE_OR_MULTIMODEMASTER(hadc)  )
    {
      /* Start ADC conversion on regular group with SW start */
      SET_BIT(hadc->Instance->CR2, (ADC_CR2_SWSTART | ADC_CR2_EXTTRIG));
    }
    else
    {
      /* Start ADC conversion on regular group with external trigger */
      SET_BIT(hadc->Instance->CR2, ADC_CR2_EXTTRIG);
    }


while in F410RE stm32f4xx_hal_adc.c it is:

 /* Check if Multimode enabled */
  if(HAL_IS_BIT_CLR(ADC->CCR, ADC_CCR_MULTI))
  {
    /* if no external trigger present enable software conversion of regular channels */
    if((hadc->Instance->CR2 & ADC_CR2_EXTEN) == RESET) 
    {
      /* Enable the selected ADC software conversion for regular group */
      hadc->Instance->CR2 |= (uint32_t)ADC_CR2_SWSTART;
    }
  }
  else
  {
    /* if instance of handle correspond to ADC1 and  no external trigger present enable software conversion of regular channels */
    if((hadc->Instance == ADC1) && ((hadc->Instance->CR2 & ADC_CR2_EXTEN) == RESET))
    {
      /* Enable the selected ADC software conversion for regular group */
        hadc->Instance->CR2 |= (uint32_t)ADC_CR2_SWSTART;
    }

For me my ADC works on all the ST Nucleo boards except STM32 F103RB, I believe in other boards it is due to the software start of ADC conversion, while for F103RB it is external trigger.

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