Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

Characteristic	Locus
Inheritance	object ObservableBase<int> SamplingSensorBase<int> PollingSensorBase<int> ByteCommsSensorBase<int> > Sgp40
Implements	IObservable<IChangeResult<int>> ISamplingSensor<int> ISensor<int> IDisposable II2cPeripheral
Inherited Members	ByteCommsSensorBase<int>.Init(int, int) ByteCommsSensorBase<int>.Dispose(bool) ByteCommsSensorBase<int>.Dispose() ByteCommsSensorBase<int>.BusComms ByteCommsSensorBase<int>.ReadBuffer ByteCommsSensorBase<int>.WriteBuffer PollingSensorBase<int>.StartUpdating(TimeSpan?) PollingSensorBase<int>.StopUpdating() SamplingSensorBase<int>.samplingLock SamplingSensorBase<int>.Read() SamplingSensorBase<int>.SamplingTokenSource SamplingSensorBase<int>.Conditions SamplingSensorBase<int>.IsSampling SamplingSensorBase<int>.UpdateInterval SamplingSensorBase<int>.Updated ObservableBase<int>.NotifyObservers(IChangeResult<int>) ObservableBase<int>.Subscribe(IObserver<IChangeResult<int>>) ObservableBase<int>.CreateObserver(Action<IChangeResult<int>>, Predicate<IChangeResult<int>>) ObservableBase<int>.observers object.Equals(object) object.Equals(object, object) object.GetHashCode() object.GetType() object.MemberwiseClone() object.ReferenceEquals(object, object) object.ToString()
Namespace	Meadow.Foundation.Sensors.Atmospheric
Assembly	Sgp40.dll

Syntax

public class Sgp40 : ByteCommsSensorBase<int>, IObservable<IChangeResult<int>>, ISamplingSensor<int>, ISensor<int>, IDisposable, II2cPeripheral

Constructors

Sgp40(II2cBus, byte)

Creates a new SGP40 VOC sensor.

Declaration

public Sgp40(II2cBus i2cBus, byte address = 89)

Parameters

Type	Name	Description
II2cBus	i2cBus	I2CBus.
byte	address	Sensor address (default to 0x40).

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

Properties

DefaultI2cAddress

The default I2C address for the peripheral

Declaration

public byte DefaultI2cAddress { get; }

Property Value

Type	Description
byte

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

SerialNumber

Serial number of the device

Declaration

public ulong SerialNumber { get; }

Property Value

Type	Description
ulong

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

VocIndex

The VOC Index, from the last reading

Declaration

public int VocIndex { get; }

Property Value

Type	Description
int

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

Methods

ClearCompensationData()

Clear the compensation data

Declaration

public void ClearCompensationData()

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

Initialize()

Initialize the sensor

Declaration

protected void Initialize()

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

RaiseEventsAndNotify(IChangeResult<int>)

Inheritance-safe way to raise events and notify observers.

Declaration

protected override void RaiseEventsAndNotify(IChangeResult<int> changeResult)

Parameters

Type	Name	Description
IChangeResult<int>	changeResult

Overrides

SamplingSensorBase<int>.RaiseEventsAndNotify(IChangeResult<int>)

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

ReadSensor()

Reads data from the sensor

Declaration

protected override Task<int> ReadSensor()

Returns

Type	Description
Task<int>	The latest sensor reading

Overrides

Meadow.Foundation.SamplingSensorBase<int>.ReadSensor()

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

RunSelfTest()

This command triggers the built-in self-test checking for integrity of both hotplate and MOX material

Declaration

public bool RunSelfTest()

Returns

Type	Description
bool	true on successful test, otherwise false

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

SetCompensationData(RelativeHumidity, Temperature)

Set the compensation data

Declaration

public void SetCompensationData(RelativeHumidity humidity, Temperature temperature)

Parameters

Type	Name	Description
RelativeHumidity	humidity	Humidity compensation
Temperature	temperature	Temperature compensation

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

TurnHeaterOff()

This command turns the hotplate off and stops the measurement. Subsequently, the sensor enters idle mode.

Declaration

public void TurnHeaterOff()

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

Events

VocIndexUpdated

Provides access to the Sensirion SGP40 VOC sensor

Declaration

public event EventHandler<ChangeResult<int>> VocIndexUpdated

Event Type

Type	Description
EventHandler<ChangeResult<int>>

Remarks

Sgp40
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Sgp40? sensor;

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

    sensor = new Sgp40(Device.CreateI2cBus());

    Resolver.Log.Info($"Sensor SN: {sensor.SerialNumber:x6}");

    if (sensor.RunSelfTest())
    {
        Resolver.Log.Info("Self test successful");
    }
    else
    {
        Resolver.Log.Warn("Self test failed");
    }

    var consumer = Sgp40.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Observer: VOC changed by threshold; new index: {result.New}");
        },
        filter: result =>
        {
            return Math.Abs(result.New - result.Old ?? 0) > 10;
        }
    );
    sensor.Subscribe(consumer);

    sensor.Updated += (sender, result) =>
    {
        Resolver.Log.Info($"  VOC: {result.New}");
    };

    return base.Initialize();
}

public override async Task Run()
{
    await ReadConditions();

    sensor?.StartUpdating(TimeSpan.FromSeconds(1));
}

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

    var result = await sensor.Read();
    Resolver.Log.Info("Initial Readings:");
    Resolver.Log.Info($"  Temperature: {result}");
}

Sample project(s) available on GitHub

Wiring Example

To wire a Sgp40 to your Meadow board, connect the following:

Sgp40	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3