Remarks

Bme688
Status Status badge: working
Source code GitHub
Datasheet(s) GitHub
NuGet package NuGet Gallery for Meadow.Foundation.Sensors.Atmospheric.Bme68x

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 =>
        {
            //c# 8 pattern match syntax. checks for !null and assigns var.
            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:

<img src="../../API_Assets/Meadow.Foundation.Sensors.Atmospheric.Bme688/Bme688_Fritzing.png"

Characteristic Locus
Inheritance System.Object ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>> SamplingSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>> PollingSensorBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>> Bme68x > Bme688
Implements ISamplingSensor<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>> ISamplingSensor<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>> ITemperatureSensor IHumiditySensor IBarometricPressureSensor
Inherited Members Bme68x.TemperatureUpdated Bme68x.PressureUpdated Bme68x.HumidityUpdated Bme68x.GasResistanceUpdated Bme68x.TemperatureOversampleMode Bme68x.PressureOversampleMode Bme68x.HumidityOversampleMode Bme68x.HeaterProfile Bme68x.FilterMode Bme68x.HeaterIsEnabled Bme68x.GasConversionIsEnabled Bme68x.Temperature Bme68x.Pressure Bme68x.Humidity Bme68x.GasResistance Bme68x.Initialize() Bme68x.Reset() Bme68x.ConfigureHeatingProfile(Bme68x.HeaterProfileType, Units.Temperature, TimeSpan, Units.Temperature) Bme68x.GetPowerMode() Bme68x.SetPowerMode(Bme68x.PowerMode) Bme68x.GetMeasurementDuration(Bme68x.HeaterProfileType) Bme68x.RaiseEventsAndNotify(IChangeResult<ValueTuple<Nullable<Units.Temperature>, Nullable<RelativeHumidity>, Nullable<Pressure>, Nullable<Resistance>>>) Bme68x.ReadSensor() Bme68x.CompensateTemperature(Int32) PollingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.StartUpdating(Nullable<TimeSpan>) PollingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.StopUpdating() SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.samplingLock SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.Updated SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.SamplingTokenSource SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.Conditions SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.IsSampling SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.UpdateInterval SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.ReadSensor() SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.RaiseEventsAndNotify(IChangeResult<>) SamplingSensorBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.Read() ObservableBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.observers ObservableBase<(Nullable<Units.Temperature> Temperature, Nullable<RelativeHumidity> Humidity, Nullable<Pressure> Pressure, Nullable<Resistance> GasResistance)>.NotifyObservers(IChangeResult<>) Meadow.Foundation.ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>>.Subscribe(IObserver<>) Meadow.Foundation.ObservableBase<System.ValueTuple<System.Nullable<Units.Temperature>, System.Nullable<RelativeHumidity>, System.Nullable<Pressure>, System.Nullable<Resistance>>>.CreateObserver(Action<>, System.Nullable<Predicate<IChangeResult<UNIT>>>)
Namespace Meadow.Foundation.Sensors.Atmospheric
Assembly Bme68x.dll

Syntax

public class Bme688 : Bme68x, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance)>, ISamplingSensor<(Units.Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance)>, ITemperatureSensor, IHumiditySensor, IBarometricPressureSensor

Constructors

Bme688(II2cBus, Byte)

Creates a new instance of the BME688 class

Declaration
public Bme688(II2cBus i2cBus, byte address = null)

Parameters

Type Name Description
II2cBus i2cBus

I2C Bus to use for communicating with the sensor
System.Byte address

I2C address of the sensor

Bme688(ISpiBus, IDigitalOutputPort, Bme68x.Configuration)

Creates a new instance of the BME688 class

Declaration
public Bme688(ISpiBus spiBus, IDigitalOutputPort chipSelectPort, Bme68x.Configuration configuration = null)

Parameters

Type Name Description
ISpiBus spiBus

The SPI bus connected to the device
IDigitalOutputPort chipSelectPort

The chip select pin
Bme68x.Configuration configuration

The BMP68x configuration (optional)

Bme688(ISpiBus, IPin)

Creates a new instance of the BME688 class

Declaration
public Bme688(ISpiBus spiBus, IPin chipSelectPin)

Parameters

Type Name Description
ISpiBus spiBus

The SPI bus connected to the device
IPin chipSelectPin

The chip select pin