/// <summary>
/// Entry point for example program
/// </summary>
/// <param name="args">Command line arguments</param>
public static void Main(string[] args)
{
Console.WriteLine("Hello Bmp280!");
// bus id on the raspberry pi 3
const int busId = 1;
// set this to the current sea level pressure in the area for correct altitude readings
var defaultSeaLevelPressure = Pressure.MeanSeaLevel;
var i2cSettings = new I2cConnectionSettings(busId, Bmp280.DefaultI2cAddress);
var i2cDevice = I2cDevice.Create(i2cSettings);
var i2CBmp280 = new Bmp280(i2cDevice);
using (i2CBmp280)
{
while (true)
{
// set higher sampling
i2CBmp280.TemperatureSampling = Sampling.LowPower;
i2CBmp280.PressureSampling = Sampling.UltraHighResolution;
// set mode forced so device sleeps after read
i2CBmp280.SetPowerMode(Bmx280PowerMode.Forced);
// wait for measurement to be performed
var measurementTime = i2CBmp280.GetMeasurementDuration();
Thread.Sleep(measurementTime);
// read values
i2CBmp280.TryReadTemperature(out var tempValue);
Console.WriteLine($"Temperature: {tempValue.Celsius} \u00B0C");
i2CBmp280.TryReadPressure(out var preValue);
Console.WriteLine($"Pressure: {preValue.Hectopascal} hPa");
i2CBmp280.TryReadAltitude(defaultSeaLevelPressure, out var altValue);
Console.WriteLine($"Altitude: {altValue} m");
Thread.Sleep(1000);
// change sampling rate
i2CBmp280.TemperatureSampling = Sampling.UltraHighResolution;
i2CBmp280.PressureSampling = Sampling.UltraLowPower;
i2CBmp280.FilterMode = Bmx280FilteringMode.X4;
// set mode forced and read again
i2CBmp280.SetPowerMode(Bmx280PowerMode.Forced);
// wait for measurement to be performed
measurementTime = i2CBmp280.GetMeasurementDuration();
Thread.Sleep(measurementTime);
// read values
i2CBmp280.TryReadTemperature(out tempValue);
Console.WriteLine($"Temperature {tempValue.Celsius} \u00B0C");
i2CBmp280.TryReadPressure(out preValue);
Console.WriteLine($"Pressure {preValue.Hectopascal} hPa");
i2CBmp280.TryReadAltitude(defaultSeaLevelPressure, out altValue);
Console.WriteLine($"Altitude: {altValue} m");
Thread.Sleep(5000);
}
}
}
/// <summary>
/// Entry point for example program
/// </summary>
/// <param name="args">Command line arguments</param>
public static void StartBmp(string[] args)
{
Console.WriteLine("Hello Bmp280!");
Length stationHeight = Length.FromMeters(640); // Elevation of the sensor
// bus id on the raspberry pi 3 and 4
const int busId = 1;
// set this to the current sea level pressure in the area for correct altitude readings
var defaultSeaLevelPressure = WeatherHelper.MeanSeaLevel;
var i2cSettings = new I2cConnectionSettings(busId, Bmp280.DefaultI2cAddress);
var i2cDevice = I2cDevice.Create(i2cSettings);
var i2CBmp280 = new Bmp280(i2cDevice);
using (i2CBmp280)
{
while (true)
{
// set higher sampling
i2CBmp280.TemperatureSampling = Sampling.LowPower;
i2CBmp280.PressureSampling = Sampling.UltraHighResolution;
// set mode forced so device sleeps after read
i2CBmp280.SetPowerMode(Bmx280PowerMode.Forced);
// wait for measurement to be performed
var measurementTime = i2CBmp280.GetMeasurementDuration();
Thread.Sleep(measurementTime);
// read values
i2CBmp280.TryReadTemperature(out var tempValue);
Console.WriteLine($"Temperature: {tempValue.DegreesCelsius} \u00B0C");
i2CBmp280.TryReadPressure(out var preValue);
Console.WriteLine($"Pressure: {preValue.Hectopascals} hPa");
// Note that if you already have the pressure value and the temperature, you could also calculate altitude by using
// double altValue = WeatherHelper.CalculateAltitude(preValue, defaultSeaLevelPressure, tempValue) which would be more performant.
i2CBmp280.TryReadAltitude(out var altValue);
Console.WriteLine($"Calculated Altitude: {altValue} m");
Thread.Sleep(1000);
// change sampling rate
i2CBmp280.TemperatureSampling = Sampling.UltraHighResolution;
i2CBmp280.PressureSampling = Sampling.UltraLowPower;
i2CBmp280.FilterMode = Bmx280FilteringMode.X4;
// set mode forced and read again
i2CBmp280.SetPowerMode(Bmx280PowerMode.Forced);
// wait for measurement to be performed
measurementTime = i2CBmp280.GetMeasurementDuration();
Thread.Sleep(measurementTime);
// read values
i2CBmp280.TryReadTemperature(out tempValue);
Console.WriteLine($"Temperature: {tempValue.DegreesCelsius} \u00B0C");
i2CBmp280.TryReadPressure(out preValue);
Console.WriteLine($"Pressure: {preValue.Hectopascals} hPa");
// This time use altitude calculation
altValue = WeatherHelper.CalculateAltitude(preValue, defaultSeaLevelPressure, tempValue);
Console.WriteLine($"Calculated Altitude: {altValue} m");
// Calculate the barometric (corrected) pressure for the local position.
// Change the stationHeight value above to get a correct reading, but do not be tempted to insert
// the value obtained from the formula above. Since that estimates the altitude based on pressure,
// using that altitude to correct the pressure won't work.
var correctedPressure = WeatherHelper.CalculateBarometricPressure(preValue, tempValue, stationHeight);
Console.WriteLine($"Pressure corrected for altitude {stationHeight.Meters} m (with average humidity): {correctedPressure.Hectopascals} hPa");
Thread.Sleep(5000);
}
}
}
