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Not getting proper results for ADC in STM32H747i-DISCO board

Pavankumar1_
Associate II

I am STM32H747i-DISCO discovery board and i configured ADC1 with 2 channels and ADC3 with 5 channels both in interrupt mode and configuration for both as below

static void MX_ADC1_Init(void)
{

/* USER CODE BEGIN ADC1_Init 0 */

/* USER CODE END ADC1_Init 0 */

ADC_MultiModeTypeDef multimode = {0};
ADC_ChannelConfTypeDef sConfig = {0};

/* USER CODE BEGIN ADC1_Init 1 */

/* USER CODE END ADC1_Init 1 */

/** Common config
*/
hadc1.Instance = ADC1;
hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV2;
hadc1.Init.Resolution = ADC_RESOLUTION_16B;
hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
hadc1.Init.EOCSelection = ADC_EOC_SEQ_CONV;
hadc1.Init.LowPowerAutoWait = DISABLE;
hadc1.Init.ContinuousConvMode = ENABLE;
hadc1.Init.NbrOfConversion = 2;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc1.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DR;
hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
hadc1.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;
hadc1.Init.OversamplingMode = DISABLE;
if (HAL_ADC_Init(&hadc1) != HAL_OK)
{
Error_Handler();
}

/** Configure the ADC multi-mode
*/
multimode.Mode = ADC_MODE_INDEPENDENT;
if (HAL_ADCEx_MultiModeConfigChannel(&hadc1, &multimode) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_13;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;
sConfig.OffsetSignedSaturation = DISABLE;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_18;
sConfig.Rank = ADC_REGULAR_RANK_2;
sConfig.SamplingTime = ADC_SAMPLETIME_8CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC1_Init 2 */

/* USER CODE END ADC1_Init 2 */

}

 

 

 

static void MX_ADC3_Init(void)
{

/* USER CODE BEGIN ADC3_Init 0 */

/* USER CODE END ADC3_Init 0 */

ADC_ChannelConfTypeDef sConfig = {0};

/* USER CODE BEGIN ADC3_Init 1 */

/* USER CODE END ADC3_Init 1 */

/** Common config
*/
hadc3.Instance = ADC3;
hadc3.Init.Resolution = ADC_RESOLUTION_16B;
hadc3.Init.ScanConvMode = ADC_SCAN_ENABLE;
hadc3.Init.EOCSelection = ADC_EOC_SEQ_CONV;
hadc3.Init.LowPowerAutoWait = DISABLE;
hadc3.Init.ContinuousConvMode = ENABLE;
hadc3.Init.NbrOfConversion = 5;
hadc3.Init.DiscontinuousConvMode = DISABLE;
hadc3.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc3.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc3.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DR;
hadc3.Init.Overrun = ADC_OVR_DATA_PRESERVED;
hadc3.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;
hadc3.Init.OversamplingMode = DISABLE;
if (HAL_ADC_Init(&hadc3) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_6;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;
sConfig.OffsetSignedSaturation = DISABLE;
if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_12;
sConfig.Rank = ADC_REGULAR_RANK_2;
if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_0;
sConfig.Rank = ADC_REGULAR_RANK_3;
if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_1;
sConfig.Rank = ADC_REGULAR_RANK_4;
if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_15;
sConfig.Rank = ADC_REGULAR_RANK_5;
if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC3_Init 2 */

/* USER CODE END ADC3_Init 2 */

}

 

and i call the HAL_ADC_Start_IT function outside the while loop and call back as mention below

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
{
if(hadc == &hadc1)
{
adc1_conversion_flag=1;
}
if(hadc == &hadc3)
{
adc3_conversion_flag=1;
}
}

 

 

and inside while loop based on the flag in the call back i include the code as shown below

 

if(adc1_conversion_flag)
{
for(uint16_t i=0;i < 2; i++)
{
adc1_conversion_value[i]=HAL_ADC_GetValue(&hadc1);
}
adc1_conversion_flag=0;
}

if(adc3_conversion_flag)
{
for(uint16_t i=0;i < 5; i++)
{
adc3_conversion_value[i]=HAL_ADC_GetValue(&hadc3);
}
adc3_conversion_flag=0;
}

 but the output is not proper if i change the voltage value in one channel it will affect all the other channels

what is the solution for this please someone suggest.

1 ACCEPTED SOLUTION

Accepted Solutions
TDK
Guru

Use DMA to convert multiple channels in a sequence.

If you feel a post has answered your question, please click "Accept as Solution".

View solution in original post

5 REPLIES 5
TDK
Guru

Use DMA to convert multiple channels in a sequence.

If you feel a post has answered your question, please click "Accept as Solution".
MM..1
Chief

ADC_SAMPLETIME_1CYCLE_5 maybe is very short.

I used DMA its working fine but with interrupt why it is not working?

How you declare adc1_conversion_flag?

Probably you aren't reading the values fast enough.

If you feel a post has answered your question, please click "Accept as Solution".