Remarks
| Scd40 | |
|---|---|
| Status |  |
| Source code | GitHub |
| Datasheet(s) | GitHub |
| NuGet package |  |
Code Example
Scd40 sensor;
public override Task Initialize()
{
Resolver.Log.Info("Initializing...");
var i2cBus = Device.CreateI2cBus(Meadow.Hardware.I2cBusSpeed.Standard);
sensor = new Scd40(i2cBus);
var serialNum = sensor.GetSerialNumber();
Resolver.Log.Info($"Serial: {BitConverter.ToString(serialNum)}");
var consumer = Scd40.CreateObserver(
handler: result =>
{
Resolver.Log.Info($"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($" Concentration: {result.New.Concentration?.PartsPerMillion:N0}ppm");
Resolver.Log.Info($" Temperature: {result.New.Temperature?.Celsius:N1}C");
Resolver.Log.Info($" Relative Humidity: {result.New.Humidity:N0}%");
};
}
sensor?.StartUpdating(TimeSpan.FromSeconds(6));
return base.Initialize();
}
Sample project(s) available on GitHub
Syntax
public class Scd40 : Scd4xBase, IObservable<IChangeResult<(Concentration? Concentration, Temperature? Temperature, RelativeHumidity? Humidity)>>, ISamplingSensor<(Concentration? Concentration, Temperature? Temperature, RelativeHumidity? Humidity)>, ISensor<(Concentration? Concentration, Temperature? Temperature, RelativeHumidity? Humidity)>, IDisposable, ITemperatureSensor, ISamplingSensor<Temperature>, ISensor<Temperature>, IHumiditySensor, ISamplingSensor<RelativeHumidity>, ISensor<RelativeHumidity>, IConcentrationSensor, ISamplingSensor<Concentration>, ISensor<Concentration>, II2cPeripheralConstructors
Scd40(II2cBus, byte)
Create a new Scd40 object
Declaration
public Scd40(II2cBus i2cBus, byte address = 98)Parameters
| Type | Name | Description |
|---|---|---|
| II2cBus | i2cBus | The I2C bus |
| byte | address | The I2C address |
Remarks
| Scd40 | |
|---|---|
| Status | |
| Source code | GitHub |
| Datasheet(s) | GitHub |
| NuGet package | |
Code Example
Scd40 sensor;
public override Task Initialize()
{
Resolver.Log.Info("Initializing...");
var i2cBus = Device.CreateI2cBus(Meadow.Hardware.I2cBusSpeed.Standard);
sensor = new Scd40(i2cBus);
var serialNum = sensor.GetSerialNumber();
Resolver.Log.Info($"Serial: {BitConverter.ToString(serialNum)}");
var consumer = Scd40.CreateObserver(
handler: result =>
{
Resolver.Log.Info($"Observer: Temp changed by threshold; new temp: {result.New.Temperature?.Celsius:N2}C, old: {result.Old?.Temperature?.Celsius:N2}C");
},
filter: result =>
{
if (result.Old?.Temperature is { } oldTemp &&
result.Old?.Humidity is { } oldHumidity &&
result.New.Temperature is { } newTemp &&
result.New.Humidity is { } newHumidity)
{
return ((newTemp - oldTemp).Abs().Celsius > 0.5 &&
(newHumidity - oldHumidity).Percent > 0.05);
}
return false;
}
);
sensor?.Subscribe(consumer);
if (sensor != null)
{
sensor.Updated += (sender, result) =>
{
Resolver.Log.Info($" Concentration: {result.New.Concentration?.PartsPerMillion:N0}ppm");
Resolver.Log.Info($" Temperature: {result.New.Temperature?.Celsius:N1}C");
Resolver.Log.Info($" Relative Humidity: {result.New.Humidity:N0}%");
};
}
sensor?.StartUpdating(TimeSpan.FromSeconds(6));
return base.Initialize();
}