I am trying to read ADC values on the Nucleo-F722ZE board.
- I have 3V from a power supply connected to pin PA3 on the Nucleo. Verified that the pin on the processor reads 3V.
- Grounds from the power supply and the Nucleo are connected.
- I checked the voltages on AVDD/VREF, they are correct at ~3.3V
However, when I read the ADC value, it shows up as ~600. 3V should give me ~3700. I have tried varying power supply voltage so that the voltage at the pin is 1V to 3V, however the values from the ADC remain constant at ~630.
I have tried the other two pins initialized in my code, PC0 and PC3, and they behave the same way.
I have a suspicion that the ADC is not configured properly. Is there something wrong with my code?
ADC_HandleTypeDef hadc1;
DMA_HandleTypeDef hdma_adc1;
/* ADC1 init function */
void MX_ADC1_Init(void)
{
ADC_ChannelConfTypeDef sConfig;
hadc1.Instance = ADC1;
hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
hadc1.Init.Resolution = ADC_RESOLUTION_12B;
hadc1.Init.ScanConvMode = ENABLE;
hadc1.Init.ContinuousConvMode = ENABLE;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc1.Init.NbrOfConversion = 5;
hadc1.Init.DMAContinuousRequests = ENABLE;
hadc1.Init.EOCSelection = ADC_EOC_SEQ_CONV;
if (HAL_ADC_Init(&hadc1) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
*/
sConfig.Channel = ADC_CHANNEL_0;
sConfig.Rank = 1;
sConfig.SamplingTime = ADC_SAMPLETIME_56CYCLES;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
*/
sConfig.Channel = ADC_CHANNEL_1;
sConfig.Rank = 2;
sConfig.SamplingTime = ADC_SAMPLETIME_56CYCLES;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
*/
sConfig.Channel = ADC_CHANNEL_2;
sConfig.Rank = 3;
sConfig.SamplingTime = ADC_SAMPLETIME_56CYCLES;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
*/
sConfig.Channel = ADC_CHANNEL_VREFINT;
sConfig.Rank = 4;
sConfig.SamplingTime = ADC_SAMPLETIME_56CYCLES;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
*/
sConfig.Channel = ADC_CHANNEL_TEMPSENSOR;
sConfig.Rank = 5;
sConfig.SamplingTime = ADC_SAMPLETIME_56CYCLES;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{
GPIO_InitTypeDef GPIO_InitStruct;
if(adcHandle->Instance==ADC1)
{
/* USER CODE BEGIN ADC1_MspInit 0 */
/* USER CODE END ADC1_MspInit 0 */
/* ADC1 clock enable */
__HAL_RCC_ADC1_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_3;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_0||GPIO_PIN_3;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/* ADC1 DMA Init */
/* ADC1 Init */
hdma_adc1.Instance = DMA2_Stream0;
hdma_adc1.Init.Channel = DMA_CHANNEL_0;
hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;
hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
hdma_adc1.Init.Mode = DMA_CIRCULAR;
hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
hdma_adc1.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
__HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc1);
/* ADC1 interrupt Init */
HAL_NVIC_SetPriority(ADC_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(ADC_IRQn);
/* USER CODE BEGIN ADC1_MspInit 1 */
/* USER CODE END ADC1_MspInit 1 */
}
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
/**Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
/**Initializes the CPU, AHB and APB busses clocks
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = 16;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Initializes the CPU, AHB and APB busses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART3;
PeriphClkInitStruct.Usart3ClockSelection = RCC_USART3CLKSOURCE_PCLK1;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
/**Configure the Systick interrupt time
*/
HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
/**Configure the Systick
*/
HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
/* SysTick_IRQn interrupt configuration */
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}
int main(void)
{
uint32_t ADC_Raw[5] = {0};
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_DMA_Init();
MX_ADC1_Init();
MX_TIM1_Init();
MX_USART3_UART_Init();
MX_TIM3_Init();
MX_NVIC_Init();
sprintf(buffer, "Nucleo Phase Shift\n");
print((char *)buffer);
HAL_ADC_Start_DMA(&hadc1, (uint32_t *)&ADC_Raw, sizeof(ADC_Raw));
HAL_Delay(250);
while (1)
{
}
}
Best Answer
I have not checked if all fields in local structs are initialized. It's good practice to explicitly initialize all local structs, e.g.
Are the values from the internal channels, VREFINT and temperature, plausible? When yes, then ADC and DMA work, and GPIO setup is probably wrong.
Are the GPIO and DMA clocks enabled? Can't find
__HAL_RCC_GPIOA_CLK_ENABLE()
,__HAL_RCC_GPIOC_CLK_ENABLE()
, or__HAL_RCC_DMA2_CLK_ENABLE()
in your code.This expression is wrong
there should be a single vertical bar
|
, meaning bitwise OR, instead of a double one||
, which is a logical OR.Make sure that other peripherals that you are using, e.g.
TIM1
, don't take DMA2 Stream0 away from the ADC.UPDATE:
ADC channel numbers are all wrong.
PA3
isADC_CHANNEL_3
PC0
isADC_CHANNEL_10
PC3
isADC_CHANNEL_13
You can get the channel numbers from the last column of Table 10 in the datasheet, or by just clicking on the pin in CubeMX.