/// <inheritdoc/>
public override ISensorSample TakeReading(WeatherObservation observation)
{
this.LogTakeReadingStart();
var sensorResult = new SensorSample(this.SensorName);
var result = this.sensor.Read();
if (result.Humidity.HasValue && result.Pressure.HasValue && result.Temperature.HasValue)
{
var pressure = result.Pressure.Value;
var temperature = new Temperature(result.Temperature.Value.DegreesCelsius + this.calibrationOffset, UnitsNet.Units.TemperatureUnit.DegreeCelsius);
var rawTemperature = result.Temperature.Value;
var humidity = result.Humidity.Value;
var actualAltitude = new Length(this.altitudeInMeters, UnitsNet.Units.LengthUnit.Meter);
var calculatedAltitude = WeatherHelper.CalculateAltitude(pressure, WeatherHelper.MeanSeaLevel, rawTemperature);
double absHumidity = WeatherHelper.CalculateAbsoluteHumidity(temperature, humidity).GramsPerCubicMeter;
double dewPoint = WeatherHelper.CalculateDewPoint(temperature, humidity).DegreesCelsius;
double heatIndex = WeatherHelper.CalculateHeatIndex(temperature, humidity).DegreesCelsius;
double vapourPressure = WeatherHelper.CalculateActualVaporPressure(temperature, humidity).Hectopascals;
double barometricPressure = WeatherHelper.CalculateBarometricPressure(pressure, temperature, actualAltitude, humidity).Hectopascals;
double vapourPressureOverIce = WeatherHelper.CalculateSaturatedVaporPressureOverIce(temperature).Hectopascals;
double vapourPressureOverWater = WeatherHelper.CalculateSaturatedVaporPressureOverWater(temperature).Hectopascals;
double seaLevelPressure = WeatherHelper.CalculateSeaLevelPressure(pressure, actualAltitude, temperature).Hectopascals;
sensorResult.AddFinalObservation(temperature.DegreesCelsius, "TEMPERATURE", ObservationUnits.DegreesCelcius);
sensorResult.AddFinalObservation(pressure.Hectopascals, "PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(barometricPressure, "BAROMETRIC PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(seaLevelPressure, "SEA LEVEL PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(vapourPressureOverIce, "OVER ICE PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(vapourPressureOverWater, "OVER WATER PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(humidity.Percent, "RELATIVE HUMIDITY", ObservationUnits.Percentage);
sensorResult.AddFinalObservation(absHumidity, "ABSOLUTE HUMIDITY", ObservationUnits.GramsPerCubicMeter);
sensorResult.AddFinalObservation(vapourPressure, "VAPOUR PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(calculatedAltitude.Meters, "CALCULATED ALTITUDE", ObservationUnits.Meters);
sensorResult.AddFinalObservation(actualAltitude.Meters, "ACTUAL ALTITUDE", ObservationUnits.Meters);
sensorResult.AddFinalObservation(heatIndex, "HEAT INDEX", ObservationUnits.DegreesCelcius);
sensorResult.AddFinalObservation(dewPoint, "DEW POINT", ObservationUnits.DegreesCelcius);
observation.Temperature1 = temperature.DegreesCelsius;
observation.Pressure = pressure.Hectopascals;
observation.BarometricPressure = barometricPressure;
observation.SealevelPressure = seaLevelPressure;
observation.OverIcePressure = vapourPressureOverIce;
observation.OverWaterPressure = vapourPressureOverWater;
observation.RelativeHumidity = humidity.Percent;
observation.AbsoluteHumidity = absHumidity;
observation.ActualAltitude = actualAltitude.Meters;
observation.CalculatedAltitude = calculatedAltitude.Meters;
observation.HeatIndex = heatIndex;
observation.DewPoint = dewPoint;
}
this.LogTakeReadingComplete();
return(sensorResult);
}
public void SaturatedVaporPressureOverIce(double expected, double celsius)
{
var saturatedVaporPressure = WeatherHelper.CalculateSaturatedVaporPressureOverIce(Temperature.FromDegreesCelsius(celsius));
Assert.Equal(expected, saturatedVaporPressure.Pascals, 1);
}
/// <inheritdoc/>
public override void Initialize()
{
this.LogStartInitialization();
this.i2cDevice = this.Controller.GetI2CConnection(this.DeviceId);
this.sensor = new Bme280(this.i2cDevice)
{
TemperatureSampling = Sampling.LowPower,
PressureSampling = Sampling.UltraHighResolution,
HumiditySampling = Sampling.Standard,
};
var readResult = this.sensor.ReadStatus();
this.LogMessage($"BME280 status {readResult}");
var result = this.sensor.Read();
if (result.Humidity.HasValue && result.Pressure.HasValue && result.Temperature.HasValue)
{
var pressure = result.Pressure.Value;
var temperature = new Temperature(result.Temperature.Value.DegreesCelsius - this.calibrationOffset, UnitsNet.Units.TemperatureUnit.DegreeCelsius);
var humidity = result.Humidity.Value;
var actualAltitude = new Length(this.altitudeInMeters, UnitsNet.Units.LengthUnit.Meter);
var calculatedAltitude = WeatherHelper.CalculateAltitude(pressure, WeatherHelper.MeanSeaLevel, temperature);
double absHumidity = WeatherHelper.CalculateAbsoluteHumidity(temperature, humidity).GramsPerCubicMeter;
double dewPoint = WeatherHelper.CalculateDewPoint(temperature, humidity).DegreesCelsius;
double heatIndex = WeatherHelper.CalculateHeatIndex(temperature, humidity).DegreesCelsius;
double vapourPressure = WeatherHelper.CalculateActualVaporPressure(temperature, humidity).Hectopascals;
double barometricPressure = WeatherHelper.CalculateBarometricPressure(pressure, temperature, actualAltitude, humidity).Hectopascals;
double vapourPressureOverIce = WeatherHelper.CalculateSaturatedVaporPressureOverIce(temperature).Hectopascals;
double vapourPressureOverWater = WeatherHelper.CalculateSaturatedVaporPressureOverWater(temperature).Hectopascals;
double seaLevelPressure = WeatherHelper.CalculateSeaLevelPressure(pressure, actualAltitude, temperature).Hectopascals;
this.LogMessage($"Temperature: {temperature.DegreesCelsius:0.#}\u00B0C");
this.LogMessage($"Pressure: {pressure.Hectopascals:0.##}hPa");
this.LogMessage($"Barometric Pressure: {barometricPressure:0.##}hPa");
this.LogMessage($"Sea level Pressure: {seaLevelPressure:0.##}hPa");
this.LogMessage($"Over ice Pressure: {vapourPressureOverIce:0.##}hPa");
this.LogMessage($"Over water Pressure: {vapourPressureOverWater:0.##}hPa");
this.LogMessage($"Relative humidity: {humidity.Percent:0.#}%");
this.LogMessage($"Absolute humidity: {absHumidity:0.#}g/m3");
this.LogMessage($"Vapour pressure: {vapourPressure:0.#}hPa");
this.LogMessage($"Calculate altitude: {calculatedAltitude.Meters:0.##}m");
this.LogMessage($"Actual altitude: {actualAltitude.Meters:0.##}m");
this.LogMessage($"Heat index: {heatIndex:0.#}\u00B0C");
this.LogMessage($"Dew point: {dewPoint:0.#}\u00B0C");
Thread.Sleep(1000);
// set sane defaults
this.sensor.TemperatureSampling = Sampling.UltraLowPower;
this.sensor.PressureSampling = Sampling.UltraLowPower;
this.sensor.HumiditySampling = Sampling.UltraLowPower;
this.sensor.FilterMode = Bmx280FilteringMode.Off;
this.sensor.SetPowerMode(Iot.Device.Bmxx80.PowerMode.Bmx280PowerMode.Forced);
this.IsInitialized = true;
this.LogStartSuccess();
}
this.LogError("Couldn't read from BME280");
}
/// <inheritdoc/>
public override ISensorSample TakeReading(WeatherObservation observation)
{
this.LogTakeReadingStart();
var sensorResult = new SensorSample(this.SensorName);
// Initialize for reading
this.Device.Write(new byte[] { REGCONTROLHUM, OVERSAMPLEHUM });
var control = GetControlCode();
this.Device.Write(new byte[] { REGCONTROL, (byte)control });
// Read calibaration data
var cal1 = this.ReadBytes(0x88, 24);
var cal2 = this.ReadBytes(0xA1, 1);
var cal3 = this.ReadBytes(0xE1, 7);
sensorResult.AddDiagnostic("Calibration data (1/2/3)");
sensorResult.AddDiagnostic(ByteOperations.PrintByteArray(cal1));
sensorResult.AddDiagnostic(ByteOperations.PrintByteArray(cal2));
sensorResult.AddDiagnostic(ByteOperations.PrintByteArray(cal3));
var calibrationData = ExtractcalibrationData(cal1, cal2, cal3);
// Pause per spec
var wait_time = GetWaitTime();
Thread.Sleep((int)wait_time / 1000);
// Read raw data
var data = this.ReadBytes(REGDATA, 8);
sensorResult.AddDiagnostic("Raw data");
sensorResult.AddDiagnostic(ByteOperations.PrintByteArray(data));
var rawTemp = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
double rawTemperature = CalculateTemperature(sensorResult, calibrationData, rawTemp, out double tFine);
// Refine pressure and adjust for temperature
var rawPressure = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
double pressureValue = CalculatePressure(sensorResult, calibrationData, rawPressure, tFine);
// Refine humidity
var rawHumidity = (data[6] << 8) | data[7];
double humidityValue = CalculateHumidity(sensorResult, calibrationData, rawHumidity, tFine);
sensorResult.AddFinalObservation(rawTemperature + this.calibrationOffset, "TEMPERATURE", ObservationUnits.DegreesCelcius);
sensorResult.AddFinalObservation(pressureValue, "PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(humidityValue, "HUMIDITY", ObservationUnits.Percentage);
var pressure = new Pressure(pressureValue, UnitsNet.Units.PressureUnit.Hectopascal);
var humidity = new RelativeHumidity(humidityValue, UnitsNet.Units.RelativeHumidityUnit.Percent);
var temperature = new Temperature(rawTemperature, UnitsNet.Units.TemperatureUnit.DegreeCelsius);
var actualAltitude = new Length(this.altitudeInMeters, UnitsNet.Units.LengthUnit.Meter);
var altitudeCalculated = WeatherHelper.CalculateAltitude(pressure);
double absHumidity = WeatherHelper.CalculateAbsoluteHumidity(temperature, humidity).GramsPerCubicMeter;
double dewPoint = WeatherHelper.CalculateDewPoint(temperature, humidity).DegreesCelsius;
double heatIndex = WeatherHelper.CalculateHeatIndex(temperature, humidity).DegreesCelsius;
double vapourPressure = WeatherHelper.CalculateActualVaporPressure(temperature, humidity).Hectopascals;
double barometricPressure = WeatherHelper.CalculateBarometricPressure(pressure, temperature, actualAltitude, humidity).Hectopascals;
double vapourPressureOverIce = WeatherHelper.CalculateSaturatedVaporPressureOverIce(temperature).Hectopascals;
double vapourPressureOverWater = WeatherHelper.CalculateSaturatedVaporPressureOverWater(temperature).Hectopascals;
double seaLevelPressure = WeatherHelper.CalculateSeaLevelPressure(pressure, actualAltitude, temperature).Hectopascals;
sensorResult.AddFinalObservation(temperature.DegreesCelsius + this.calibrationOffset, "TEMPERATURE", ObservationUnits.DegreesCelcius);
sensorResult.AddFinalObservation(pressure.Hectopascals, "PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(barometricPressure, "BAROMETRIC PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(seaLevelPressure, "SEA LEVEL PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(vapourPressureOverIce, "OVER ICE PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(vapourPressureOverWater, "OVER WATER PRESSURE", ObservationUnits.HectoPascal);
sensorResult.AddFinalObservation(humidity.Percent, "RELATIVE HUMIDITY", ObservationUnits.Percentage);
sensorResult.AddFinalObservation(absHumidity, "ABSOLUTE HUMIDITY", ObservationUnits.GramsPerCubicMeter);
sensorResult.AddFinalObservation(vapourPressure, "VAPOUR PRESSURE", ObservationUnits.Percentage);
sensorResult.AddFinalObservation(altitudeCalculated.Meters, "CALCULATED ALTITUDE", ObservationUnits.Meters);
sensorResult.AddFinalObservation(actualAltitude.Meters, "ACTUAL ALTITUDE", ObservationUnits.Meters);
sensorResult.AddFinalObservation(heatIndex, "HEAT INDEX", ObservationUnits.DegreesCelcius);
sensorResult.AddFinalObservation(dewPoint, "DEW POINT", ObservationUnits.DegreesCelcius);
observation.Temperature1 = temperature.DegreesCelsius + this.calibrationOffset;
observation.Pressure = pressure.Hectopascals;
observation.BarometricPressure = barometricPressure;
observation.SealevelPressure = seaLevelPressure;
observation.OverIcePressure = vapourPressureOverIce;
observation.OverWaterPressure = vapourPressureOverWater;
observation.RelativeHumidity = humidity.Percent;
observation.AbsoluteHumidity = absHumidity;
observation.ActualAltitude = actualAltitude.Meters;
observation.CalculatedAltitude = altitudeCalculated.Meters;
observation.HeatIndex = heatIndex;
observation.DewPoint = dewPoint;
this.LogTakeReadingComplete();
return(sensorResult);
}