ADC

[meena]

the code generated for my channels if i initialize this channels and

 hadc1.Instance = ADC1;
  hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
  hadc1.Init.Resolution = ADC_RESOLUTION_12B;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.ScanConvMode = ADC_SCAN_SEQ_FIXED;
  hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  hadc1.Init.LowPowerAutoWait = DISABLE;
  hadc1.Init.LowPowerAutoPowerOff = DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.NbrOfConversion = 1;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc1.Init.DMAContinuousRequests = DISABLE;
  hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  hadc1.Init.SamplingTimeCommon1 = ADC_SAMPLETIME_39CYCLES_5;
  hadc1.Init.OversamplingMode = DISABLE;
  hadc1.Init.TriggerFrequencyMode = ADC_TRIGGER_FREQ_HIGH;
  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_2;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_5;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_9;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_15;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_16;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN ADC1_Init 2 */

  /* USER CODE END ADC1_Init 2 */

}

i am getting same value for all the adc value

[Pierre_Paris]

Hello @meena,

Thank you for your question!

Here some remark :

• Do you know there are example code existing ? You can get software here (you can go under the root STM32Cube_FW_G0_V1.6.0\Projects\NUCLEOG071RB\Examples\ADC\ADC_MultiChannelSingleConversion).
• Are you sure for NbrOfConversion = 1 ? You declared 6 regular channels right ?
• For the overrun case, my advise is to use ADC_OVR_DATA_OVERWRITTEN.
• Do you want to use the DMA feature with the ADC ? 
• I don't see any calibration before to start the ADC. You need to.

Best Regards,

Pierre

[meena]

Thanks for the reply.This is what like I configured The no.of conversion made to 6 also getting same values 

void ADC_Vbat(void)
	{
	ADC_ChannelConfTypeDef sConfig = {0};

	sConfig.Channel = ADC_CHANNEL_16;
	 sConfig.Rank = ADC_REGULAR_RANK_1;
	sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
	  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
	  {
	    Error_Handler();
	  }
	  HAL_ADC_Start(&hadc1);
	  	  	  		HAL_ADC_PollForConversion(&hadc1, 1000);
	  	  	  		Vbat = HAL_ADC_GetValue(&hadc1);
	  	  	  		//Vbat = (Vbat * 3.3)/ 4095;
	  	  	  		HAL_ADC_Stop(&hadc1);



	}
void ADC_BattIsense(void)
	{
	ADC_ChannelConfTypeDef sConfig = {0};
	 sConfig.Channel = ADC_CHANNEL_3;
	  sConfig.Rank = ADC_REGULAR_RANK_2;
	  sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
	  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
	  {
	    Error_Handler();
	  }
	  HAL_ADC_Start(&hadc1);
	 	  	  	  		HAL_ADC_PollForConversion(&hadc1, 1000);
	 	  	  	  		BattI = HAL_ADC_GetValue(&hadc1);
	 	  	  	  		HAL_ADC_Stop(&hadc1);


	}
void ADC_ledIsense(void)
	{
	ADC_ChannelConfTypeDef sConfig = {0};
		 sConfig.Channel = ADC_CHANNEL_2;
		 sConfig.Rank = ADC_REGULAR_RANK_3;
			sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
		  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
		  {
		    Error_Handler();
		  }
		  HAL_ADC_Start(&hadc1);
		 	  	  	  		HAL_ADC_PollForConversion(&hadc1, 1000);
		 	  	  	  		LedI = HAL_ADC_GetValue(&hadc1);
		 	  	  	  		HAL_ADC_Stop(&hadc1);
	}
void ADC_Temp(void)
{
	ADC_ChannelConfTypeDef sConfig = {0};
	sConfig.Channel = ADC_CHANNEL_0;
	  sConfig.Rank = ADC_REGULAR_RANK_4;
	  sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
	  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
	  {
	    Error_Handler();
	  }
	  HAL_ADC_Start(&hadc1);
	  		 	  	  	  		HAL_ADC_PollForConversion(&hadc1, 1000);
	  		 	  	  	  		Temp = HAL_ADC_GetValue(&hadc1);
	  		 	  	  	  		HAL_ADC_Stop(&hadc1);
}
void Open_Circuit(void)
{
	ADC_ChannelConfTypeDef sConfig = {0};
	 sConfig.Channel = ADC_CHANNEL_9;
	  sConfig.Rank = ADC_REGULAR_RANK_5;
	  sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_2;
	  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
	  {
	    Error_Handler();
	  }
	  HAL_ADC_Start(&hadc1);
	 	  		 	  	  	  		HAL_ADC_PollForConversion(&hadc1, 1000);
	 	  		 	  	  	  		Opv = HAL_ADC_GetValue(&hadc1);
	 	  		 	  	  	  		HAL_ADC_Stop(&hadc1);
}

[Pierre_Paris · Accepted solution]

Hello @meena,

Here some additional information :

• HAL_ADC_ConfigChannel() configure a channel to be assigned to ADC group regular. That means you are configuring the channel every time you want to start conversions, that's a waste of time. You should configure once and if you want to update parameters on the fly without resetting the ADC, please use ADC_ChannelConfTypeDef().
• You want to use the polling mode, you respected well the four points below :
  • Activate ADC peripheral and start conversions using function HAL_ADC_Start()
  • Wait for ADC conversion completion using function HAL_PollForConversion()
  • Retrieve conversion results using function HAL_ADC_GetValue()
  • Stop conversion and disable the ADC peripheral using function HAL_ADC_Stop()
• But in the polling mode, you are polling the EOC (End Of Conversion) single flag configured with EOCSelection. You should set this parameter to ADC_EOC_SEQ_CONV and poll this flag to indicate the end of sequence conversions. If I understood your application, the best option for you is starting once the ADC, polling the right flag and then stop the ADC. 
• "ScanConvMode = ADC_SCAN_SEQ_FIXED" set to not fully configurable : number of ranks in the scan sequence is defined by number of channels set in the sequence, rank of each channel is fixed by channel HW number (channel 0 fixed on rank 0...). But you are affecting each rank to a channel as in the fully configurable mode (eg: channel 9 to rank 5). You may have to change that.

Best Regards,

Pierre

[hongmei]

Hello,

I use 4 channels of ADC1 in my program. But, when I see the result by HAL_ADC_GetValue() function,

the results of channel0~channel3 of ADC1 are all same.

Could you tell me the reason of this phenomenon?

Thank you!