NTC-Temperature Sensor
I used STM32F072C8T6.
ADC - IN0, IN1 set.
An application that measures temperature with an NTC temperature sensor.
- PullUp resistance 10K was connected to Vdd (3.29V) and PA0, PA1..
- When the HAL_ADC_Start_DMA function is executed, the voltage of ADC - PA0, PA1 is measured by 3.7 (V).
- If the HAL_ADC_Start_DMA function is not run (normal GPIO call setup), 3.29(V) is measured normally.
- How can it be higher than the input voltage of 3.29(V)?
- Normal ADC not available.
static void MX_ADC_Init(void)
{
/** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
*/
hadc.Instance = ADC1;
hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;
hadc.Init.Resolution = ADC_RESOLUTION_12B;
hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
hadc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
hadc.Init.LowPowerAutoWait = DISABLE;
hadc.Init.LowPowerAutoPowerOff = DISABLE;
hadc.Init.ContinuousConvMode = ENABLE;
hadc.Init.DiscontinuousConvMode = DISABLE;
hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc.Init.DMAContinuousRequests = ENABLE;
hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED;
if (HAL_ADC_Init(&hadc) != HAL_OK)
{
Error_Handler();
}
/** Configure for the selected ADC regular channel to be converted.
*/
sConfig.Channel = ADC_CHANNEL_0;
sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
sConfig.SamplingTime = ADC_SAMPLETIME_41CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}
/** Configure for the selected ADC regular channel to be converted.
*/
sConfig.Channel = ADC_CHANNEL_1;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC_Init 2 */
/* USER CODE END ADC_Init 2 */
}
void HW_AdcInit()
{
while(HAL_ADCEx_Calibration_Start(&hadc) != HAL_OK);
HAL_ADC_Start_DMA(&hadc, (uint32_t *)adcValue, 2);
}
I want to know the solution.
Thanks.