Meadow.Foundation.Sensors.Atmospheric.Bme688

Bme688
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Bme688? sensor;

public override Task Initialize()
{
    Resolver.Log.Info("Initializing...");

    //CreateSpiSensor();
    CreateI2CSensor();

    //uncomment to enable on sensor heater for gas readings
    //EnableGasHeater();

    var consumer = Bme688.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: Temp changed by threshold; new temp: {result.New.Temperature?.Celsius:N2}C, old: {result.Old?.Temperature?.Celsius:N2}C");
        },
        filter: result =>
        {
            if (result.Old?.Temperature is { } oldTemp &&
                result.Old?.Humidity is { } oldHumidity &&
                result.New.Temperature is { } newTemp &&
                result.New.Humidity is { } newHumidity)
            {
                return ((newTemp - oldTemp).Abs().Celsius > 0.5 &&
                        (newHumidity - oldHumidity).Percent > 0.05);
            }
            return false;
        }
    );

    sensor?.Subscribe(consumer);

    if (sensor != null)
    {
        sensor.Updated += (sender, result) =>
        {
            Resolver.Log.Info($"  Temperature: {result.New.Temperature?.Celsius:N2}C");
            Resolver.Log.Info($"  Relative Humidity: {result.New.Humidity:N2}%");
            Resolver.Log.Info($"  Pressure: {result.New.Pressure?.Millibar:N2}mbar ({result.New.Pressure?.Pascal:N2}Pa)");
            if (sensor.GasConversionIsEnabled)
            {
                Resolver.Log.Info($"  Gas Resistance: {result.New.GasResistance:N0}Ohms");
            }
        };
    }

    sensor?.StartUpdating(TimeSpan.FromSeconds(2));

    ReadConditions().Wait();

    return base.Initialize();
}

void EnableGasHeater()
{
    if (sensor != null)
    {
        sensor.GasConversionIsEnabled = true;
        sensor.HeaterIsEnabled = true;
        sensor.ConfigureHeatingProfile(Bme688.HeaterProfileType.Profile1, new Temperature(300), TimeSpan.FromMilliseconds(100), new Temperature(22));
        sensor.HeaterProfile = Bme688.HeaterProfileType.Profile1;
    }
}

void CreateSpiSensor()
{
    Resolver.Log.Info("Create BME688 sensor with SPI...");

    var spiBus = Device.CreateSpiBus();
    sensor = new Bme688(spiBus, Device.CreateDigitalOutputPort(Device.Pins.D01));
}

void CreateI2CSensor()
{
    Resolver.Log.Info("Create BME688 sensor with I2C...");

    var i2c = Device.CreateI2cBus();
    sensor = new Bme688(i2c, (byte)Bme688.Addresses.Address_0x76);
}

async Task ReadConditions()
{
    if (sensor == null) { return; }

    var (Temperature, Humidity, Pressure, Resistance) = await sensor.Read();

    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {Temperature?.Celsius:N2}C");
    Resolver.Log.Info($"  Pressure: {Pressure?.Hectopascal:N2}hPa");
    Resolver.Log.Info($"  Relative Humidity: {Humidity?.Percent:N2}%");
    Resolver.Log.Info($"  Gas Resistance: {Resistance?.Ohms:N0}Ohms");
}

Sample project(s) available on GitHub

Wiring Example

To wire a BME688 to your Meadow board, connect the following: