Results of ADC1 garbage as soon as ADC2 starts

[alimynn]

Hi

I have the following problem on my STM32F103C8T for which I have no clue how to continue. I am running the ADC1 with DMA in continuous conversion mode scanning 6 input signals. Everything works fine. Next step was activating ADC2 triggered by TIM1 for synchronous sampling with PWM to capture an additional signal. Now, ADC2 works fine while the raw data of ADC1 is garbage meaning any random huge numbers. For me it looks like a memory problem but the configurations seems working as long as ADC2 is not started. Both ADCs are running in independent mode. Can it be that DMA of ADC1 is influenced by ADC2 as it has no separate DMA?

Main function

 

int main(void)
{
 HAL_Init();
 SystemClock_Config();
 RCC->APB2ENR |= RCC_APB2ENR_AFIOEN; // Enable A.F. clock
 AFIO->MAPR |= AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // JTAG is disabled, SWD is enabled
 MX_GPIO_Init();
 MX_DMA_Init();
 MX_I2C1_Init();
 MX_USART1_UART_Init();
 MX_USART3_UART_Init();
 MX_ADC1_Init();
 MX_TIM2_Init();
 MX_TIM1_Init();
 MX_TIM4_Init();
 MX_TIM3_Init();
 MX_ADC2_Init();

 HAL_TIM_Base_Start(&htim1);
 HAL_TIM_OC_Start(&htim1, TIM_CHANNEL_3);

 HAL_TIM_Base_Start_IT(&htim2);
 HAL_TIM_Base_Start_IT(&htim3);

 HAL_ADCEx_Calibration_Start(&hadc1);
 HAL_ADCEx_Calibration_Start(&hadc2);
 HAL_ADC_Start_DMA(&hadc1, adc_data, ADC_NUM_CHANNELS);
 HAL_ADC_Start(&hadc2);

 while (1)
 {
 /* USER CODE END WHILE */

 /* USER CODE BEGIN 3 */
 }
 /* USER CODE END 3 */
}

 

ADC1 init

 

static void MX_ADC1_Init(void)
{

 /* USER CODE BEGIN ADC1_Init 0 */

 /* USER CODE END ADC1_Init 0 */

 ADC_ChannelConfTypeDef sConfig = {0};

 /* USER CODE BEGIN ADC1_Init 1 */

 /* USER CODE END ADC1_Init 1 */

 /** Common config
 */
 hadc1.Instance = ADC1;
 hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
 hadc1.Init.ContinuousConvMode = ENABLE;
 hadc1.Init.DiscontinuousConvMode = DISABLE;
 hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
 hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
 hadc1.Init.NbrOfConversion = 6;
 if (HAL_ADC_Init(&hadc1) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_1;
 sConfig.Rank = ADC_REGULAR_RANK_1;
 sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_3;
 sConfig.Rank = ADC_REGULAR_RANK_2;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_4;
 sConfig.Rank = ADC_REGULAR_RANK_3;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_5;
 sConfig.Rank = ADC_REGULAR_RANK_4;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_6;
 sConfig.Rank = ADC_REGULAR_RANK_5;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_7;
 sConfig.Rank = ADC_REGULAR_RANK_6;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN ADC1_Init 2 */

 /* USER CODE END ADC1_Init 2 */

}

 

ADC2 init 

 

static void MX_ADC2_Init(void)
{

 /* USER CODE BEGIN ADC2_Init 0 */

 /* USER CODE END ADC2_Init 0 */

 ADC_ChannelConfTypeDef sConfig = {0};

 /* USER CODE BEGIN ADC2_Init 1 */

 /* USER CODE END ADC2_Init 1 */

 /** Common config
 */
 hadc2.Instance = ADC2;
 hadc2.Init.ScanConvMode = ADC_SCAN_DISABLE;
 hadc2.Init.ContinuousConvMode = DISABLE;
 hadc2.Init.DiscontinuousConvMode = DISABLE;
 hadc2.Init.ExternalTrigConv = ADC_EXTERNALTRIGCONV_T1_CC3;
 hadc2.Init.DataAlign = ADC_DATAALIGN_RIGHT;
 hadc2.Init.NbrOfConversion = 1;
 if (HAL_ADC_Init(&hadc2) != HAL_OK)
 {
 Error_Handler();
 }

 /** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_0;
 sConfig.Rank = ADC_REGULAR_RANK_1;
 sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
 if (HAL_ADC_ConfigChannel(&hadc2, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN ADC2_Init 2 */

 /* USER CODE END ADC2_Init 2 */

}

 

 TIM1 init

 

static void MX_TIM1_Init(void)
{

 /* USER CODE BEGIN TIM1_Init 0 */

 /* USER CODE END TIM1_Init 0 */

 TIM_ClockConfigTypeDef sClockSourceConfig = {0};
 TIM_MasterConfigTypeDef sMasterConfig = {0};
 TIM_OC_InitTypeDef sConfigOC = {0};
 TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};

 /* USER CODE BEGIN TIM1_Init 1 */

 /* USER CODE END TIM1_Init 1 */
 htim1.Instance = TIM1;
 htim1.Init.Prescaler = 1;
 htim1.Init.CounterMode = TIM_COUNTERMODE_CENTERALIGNED1;
 htim1.Init.Period = 500;
 htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim1.Init.RepetitionCounter = 0;
 htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
 if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
 {
 Error_Handler();
 }
 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
 if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_TIM_OC_Init(&htim1) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
 if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sConfigOC.OCMode = TIM_OCMODE_PWM1;
 sConfigOC.Pulse = 100;
 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
 sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
 sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
 sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
 sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
 if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
 {
 Error_Handler();
 }
 sConfigOC.OCMode = TIM_OCMODE_TOGGLE;
 sConfigOC.Pulse = 0;
 if (HAL_TIM_OC_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
 {
 Error_Handler();
 }
 sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
 sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
 sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
 sBreakDeadTimeConfig.DeadTime = 0;
 sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
 sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
 sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
 if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN TIM1_Init 2 */

 /* USER CODE END TIM1_Init 2 */
 HAL_TIM_MspPostInit(&htim1);

}

 

 ADC2 value reading

 

void adc_convert_samples()
{
	adc_data2 		 = HAL_ADC_GetValue(&hadc2);
}

 

 Thank you for any suggestions.

[Laurids_PETERSEN]

This post has been removed due to it containing AI-generated content.

[alimynn]

Thank you for your suggestions. The DMA is configured as follows.

static void MX_DMA_Init(void)
{

 /* DMA controller clock enable */
 __HAL_RCC_DMA1_CLK_ENABLE();

 /* DMA interrupt init */
 /* DMA1_Channel1_IRQn interrupt configuration */
 HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);

}

I will try your proposal to check the DMA interrupt flags.

[TDK]

At a guess, slow down ADC1 conversions by increasing sampling time. Could be swamping the system with interrupts or otherwise causing issues.

How exactly are you viewing the ADC1 data to determine it's garbage? Your program doesn't do anything with the data from what you've shown.

[alimynn]

I was not showing the part where the data is used. I will explain in the following.

An array of the data is defined in main.c (ADC_NUM_CHANNELS is defined as 6)

uint32_t adc_data[ADC_NUM_CHANNELS];

This pointer is handed over to another file responsible for the ADC conversion using

initialize_adc(&hadc1, &f_adc, adc_data);

In the ADC.c file:

 

uint32_t* data;
uint32_t data2;
ADC_HandleTypeDef* hadc;
extern ADC_HandleTypeDef hadc2;
ADCFrame* adc;

void initialize_adc(ADC_HandleTypeDef* adc_handle, ADCFrame* adc_frame, uint32_t* data_array)
{
	hadc = adc_handle;
	adc = adc_frame;
	data = data_array;
}

void adc_print_samples()
{
 data2 		= HAL_ADC_GetValue(&hadc2);
	printf("\n\r");
	printf("%lu\r\n", data2);
	for(int i=0; i < ADC_NUM_CHANNELS; i++)
	{
		printf("%lu\r\n", data[i]);
	}
}

When I call the function adc_print_samples(), I see that data2 has a value around 2000 while all values inside data are somewhere around 1500000.

[TDK]

You're using a buffer of uint32_t. Typically ADC data is stored as a uint16_t. That's a likely issue.

 

[Piranha]

In Dual ADC mode the ADC1_DR register contains the data from both ADC1 and ADC2...