Averaging an analog value.

Projects General Guidance
5

I use the Simple Kalman Filter library GitHub - denyssene/SimpleKalmanFilter: A basic implementation of Kalman Filter for single variable models., which may be of interest to you.

An example of use:

void TrackSun( void * pvParameters )
{
  int Altitude = 1500;
  int Azimuth = 1500;
  int maxAltitudeRange = 2144;
  int minAltitudeRange = 900;
  int maxAzimuthRange = 2144;
  int minAzimuthRange = 900;
  SimpleKalmanFilter kfAltitude0( 10.0, 10.0, .01 ); // kalman filter Altitude 0
  SimpleKalmanFilter kfAltitude1( 10.0, 10.0, .01 ); // kalman filter Altitude 1
  SimpleKalmanFilter kfAzimuth0( 5.0, 10.0, .01 ); // kalman filter Azimuth 0
  SimpleKalmanFilter kfAzimuth1( 5.0, 10.0, .01 ); // kalman filter Azimuth 1
  float filteredAltitude_0 = 0.0f;
  float filteredAltitude_1 = 0.0f;
  float filteredAzimuth_0 = 0.0f;
  float filteredAzimuth_1 = 0.0f;
  int64_t AzimuthEndTime = esp_timer_get_time();
  int64_t AzimuthStartTime = esp_timer_get_time(); //gets time in uSeconds like Arduino Micros,
  int64_t AltitudeEndTime = esp_timer_get_time();
  int64_t AltitudeStartTime = esp_timer_get_time();

  while (1)
  {
    //Altitude
    AltitudeEndTime = esp_timer_get_time() - AltitudeStartTime; // produce elasped time for the simpleKalmanFilter
    kfAltitude0.setProcessNoise( (float)AltitudeEndTime / 1000000.0f ); //convert time of process to uS, update SimpleKalmanFilter q
    kfAltitude1.setProcessNoise( (float)AltitudeEndTime / 1000000.0f ); //convert time of process to uS, update SimpleKalmanFilter q
    filteredAltitude_0 = kfAltitude0.updateEstimate( (float)adc1_get_raw(ADC1_CHANNEL_3) );
    filteredAltitude_1 = kfAltitude1.updateEstimate( (float)adc1_get_raw(ADC1_CHANNEL_0) );
    if ( filteredAltitude_0 > filteredAltitude_1 )
    {
      Altitude -= 1;
      if ( Altitude < minAltitudeRange )
      {
        Altitude = 1500;
      }
      fMoveAltitude( Altitude );
      vTaskDelay( 12 );
      AltitudeStartTime = esp_timer_get_time();
    }
    if ( filteredAltitude_0 < filteredAltitude_1 )
    {
      Altitude += 1;
      if ( Altitude >= maxAltitudeRange )
      {
        Altitude = 1500;
      }
      fMoveAltitude( Altitude );
      vTaskDelay( 12 );
      AltitudeStartTime = esp_timer_get_time();
    }
    //// AZIMUTH
    AzimuthEndTime = esp_timer_get_time() - AzimuthStartTime; // produce elasped time for the simpleKalmanFilter
    kfAzimuth0.setProcessNoise( (float)AzimuthEndTime / 1000000.0f ); //convert time of process to uS, update SimpleKalmanFilter q
    kfAzimuth1.setProcessNoise( (float)AzimuthEndTime / 1000000.0f ); //convert time of process to uS, update SimpleKalmanFilter q
    filteredAzimuth_0 = kfAzimuth0.updateEstimate( (float)adc1_get_raw(ADC1_CHANNEL_5) );
    filteredAzimuth_1 = kfAzimuth1.updateEstimate( (float)adc1_get_raw(ADC1_CHANNEL_6) );
    if ( filteredAzimuth_0 > filteredAzimuth_1 )
    {
      Azimuth += 1;
      if ( Azimuth >= maxAzimuthRange )
      {
        Azimuth = 900;
      }
      fMoveAzimuth( Azimuth );
      vTaskDelay( 12 );
      AzimuthStartTime = esp_timer_get_time();
    }
    if ( filteredAzimuth_0 < filteredAzimuth_1 )
    {
      Azimuth -= 1;
      if ( (Azimuth >= maxAzimuthRange) || (Azimuth <= minAzimuthRange) )
      {
        Azimuth = 900;
      }
      fMoveAzimuth( Azimuth );
      vTaskDelay( 12 );
      AzimuthStartTime = esp_timer_get_time();
    }
    // Serial.println();
    vTaskDelay( 30 );
    //
  } // while(1)
} //void TrackSun()

Instead of using a static time, I use a dynamic time, which works much better.