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Associate II
November 22, 2023
Solved

Not getting proper results for ADC in STM32H747i-DISCO board

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.

This topic has been closed for replies.
TDK
TDKBest answer
November 22, 2023

Use DMA to convert multiple channels in a sequence.

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

5 replies

TDK
TDKBest answer
November 22, 2023

Use DMA to convert multiple channels in a sequence.

"If you feel a post has answered your question, please click ""Accept as Solution""."
Associate II
November 23, 2023

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

MM..1
Super User
November 23, 2023

How you declare adc1_conversion_flag?

MM..1
Super User
November 22, 2023

ADC_SAMPLETIME_1CYCLE_5 maybe is very short.