Solved
How to measure VBAT using ADC correctly in STM32L476 MCU
Hi everyone!
I'm having trouble in measuring the VBAT through ADC. I'm using 3.3V on aNUCLEO_476 board to connect to VBAT and when I measure VBAT through ADC,I cannot obtain the value of the VBAT
Here's my code:
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_DIV1;
hadc1.Init.Resolution = ADC_RESOLUTION_12B;
hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
hadc1.Init.LowPowerAutoWait = DISABLE;
hadc1.Init.ContinuousConvMode = ENABLE;
hadc1.Init.NbrOfConversion = 7;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc1.Init.DMAContinuousRequests = ENABLE;
hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
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_VREFINT;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_247CYCLES_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_3;
sConfig.Rank = ADC_REGULAR_RANK_2;
sConfig.SamplingTime = ADC_SAMPLETIME_92CYCLES_5;
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_7;
sConfig.Rank = ADC_REGULAR_RANK_5;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_13;
sConfig.Rank = ADC_REGULAR_RANK_6;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_VBAT;
sConfig.Rank = ADC_REGULAR_RANK_7;
sConfig.SamplingTime = ADC_SAMPLETIME_247CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC1_Init 2 */
/* USER CODE END ADC1_Init 2 */
}
/* USER CODE BEGIN PV */
uint16_t adc_data_buffer[7]; /* ADC常规转换数据 */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
void PeriphCommonClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
//NVIC_Redirect();
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* Configure the peripherals common clocks */
PeriphCommonClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_ADC1_Init();
MX_I2C2_Init();
MX_I2C3_Init();
MX_UART5_Init();
MX_TIM2_Init();
/* USER CODE BEGIN 2 */
other_Init();
// ADC Calibration
HAL_ADCEx_Calibration_Start(&hadc1, ADC_SINGLE_ENDED);
HAL_ADC_Start_DMA(&hadc1, (uint32_t *)adc_data_buffer, 7);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
ProcessADCValues(adc_data_buffer, 7);
main_Task();
}
/* USER CODE END 3 */
}
void ProcessADCValues(volatile uint16_t *adcData, uint8_t length)
{
for (uint8_t i = 0; i < length; i++)
{
// 处理每个通道的数据
switch (i)
{
case 0:
VREF_voltage = get_VREF(adcData[0]); //
break;
case 1:
ILIM_MonitorI = get_MP5087_ILIM(adcData[1]); // ADC channel 3, ilim_monitor
break;
case 2:
ILIM_MonitorI2 = get_MP5087_ILIM(adcData[2]); // ADC channel 4, ilim_monitor1
break;
case 3:
Tosa_temp1 = get_NBC103_Temp(adcData[3]); // ADC channel 5, TOSA_TEMP1
break;
case 4:
Moudle_temp = get_TH05_Temp(adcData[4]); // ADC channel 7, module_temp
break;
case 5:
Tosa_temp2 = get_NBC103_Temp(adcData[5]); // ADC channel 13, TOSA_TEMP2
break;
case 6:
Vbat_voltage = get_Vbat(adcData[6], VREF_voltage);
break;
default:
break;
}
}
}#define VREFINT_ADDR ((uint16_t *)0x1FFF75AA)
float get_VREF(uint16_t adc_value)
{
uint16_t vrefint_cal = *VREFINT_ADDR;
float vref_actual = (3.0f * vrefint_cal) / adc_value;
return vref_actual;
}
float get_Vbat(uint16_t adc_value, float vref_voltage)
{
float vbat = (adc_value * vref_voltage) / 4095.0f;
return vbat;
}Can anyone please tell me where I'm doing it wrong?