Internal Temperature Sensor Reading of STM32 only updating after Reset

Question

We are reading Internal Temperature Sensor reading of STM32-F410RB - NUCLEO 64 Board.

Problem:

Getting the reading of Temperature sensor every 1 second as programmed, but the same readings are got. Only when Reset is done, the Temperature Reading get updated

Current Setup

1. Windows 10 64bit
2. STM32 Nucleo 64 - F410RB
3. Using CubeMX IDE
4. PuTTy for Serial Monitoring

STM32 CUBE MX IDE Configurations Done

1. System Core - Serial Wire
2. Analog - ADC1 - Enabled Temperature Sensor Channel
   Parameter Settings - ADC Setting - Scan Conversion & Continues Conversion Enabled Rank - Sample Time - 480 Cycles
3. USART2 - 9600 Baud Rate

CODE Snippet of Main

int main(void)
{
  
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_USART2_UART_Init();
  MX_ADC1_Init();
  HAL_ADC_Start(&hadc1);

  while (1)
  {
      uint16_t readValue;
      float tCelsius;
      readValue = HAL_ADC_GetValue(&hadc1);
      tCelsius = ((float)readValue) * 3300.0 / 4095.0; // To mV
      tCelsius = (tCelsius - 500.0) / 10.0; // To degrees C
      UART_SEND_TXT(&huart2, "Temperature = ", 0);
      UART_SEND_FLT(&huart2, tCelsius, 1);
      HAL_Delay(1000);
  }
}

Please kindly help. Thanks in Advance.

Answer 1

There is only one HAL_ADC_Start outside the loop. Therefore conversion starts only once.

Inside the loop you just repeatedly receive the last result of the conversion by HAL_ADC_GetValue.

You need to start regular group conversion by calling HAL_ADC_Start each time, then wait conversion to end by HAL_ADC_PollForConversion and, at last, get the result by HAL_ADC_GetValue