If Battery Voltages is Less than the Threshold Values then Circuit should stop

Other Hardware 3rd Party Boards
10

The variance in voltage readings from moment to moment is a normal thing that many people use some sort of filtering to smooth out.

A moving average filter works fairly well, GitHub - sebnil/Moving-Avarage-Filter--Arduino-Library-: A moving average, also called rolling average, rolling mean or running average, is a type of finite impulse response filter (FIR) used to analyze a set of datum points by creating a series of averages of different subsets of the full data set.

Me, I use a SimpleKalman Filter to do the job like so, GitHub - denyssene/SimpleKalmanFilter: A basic implementation of Kalman Filter for single variable models.

void fReadBattery( void * parameter )
{
  float adcValue = 0.0f;
  const float r1 = 50500.0f; // R1 in ohm, 50K
  const float r2 = 10000.0f; // R2 in ohm, 10k potentiometer
  float Vbatt = 0.0f;
  int printCount = 0;
  float vRefScale = (3.3f / 4096.0f) * ((r1 + r2) / r2);
  uint64_t TimePastKalman  = esp_timer_get_time(); // used by the Kalman filter UpdateProcessNoise, time since last kalman calculation
  SimpleKalmanFilter KF_ADC_b( 1.0f, 1.0f, .01f );
  TickType_t xLastWakeTime = xTaskGetTickCount();
  const TickType_t xFrequency = 1000; //delay for mS
  for (;;)
  {
    adc1_get_raw(ADC1_CHANNEL_0); //read and discard
    adcValue = float( adc1_get_raw(ADC1_CHANNEL_0) ); //take a raw ADC reading
    KF_ADC_b.setProcessNoise( (esp_timer_get_time() - TimePastKalman) / 1000000.0f ); //get time, in microsecods, since last readings
    adcValue = KF_ADC_b.updateEstimate( adcValue ); // apply simple Kalman filter
    Vbatt = adcValue * vRefScale;
    xSemaphoreTake( sema_CalculatedVoltage, portMAX_DELAY );
    CalculatedVoltage = Vbatt;
    xSemaphoreGive( sema_CalculatedVoltage );
    /*
      printCount++;
      if ( printCount == 3 )
      {
      log_i( "Vbatt %f", Vbatt );
      printCount = 0;
      }
    */
    TimePastKalman = esp_timer_get_time(); // time of update complete
    xLastWakeTime = xTaskGetTickCount();
    vTaskDelayUntil( &xLastWakeTime, xFrequency );
    //log_i( "fReadBattery %d",  uxTaskGetStackHighWaterMark( NULL ) );
  }
  vTaskDelete( NULL );
}
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