Meadow.Foundation.Sensors.Temperature.Thermistor

Thermistor
Status
Source code	GitHub
NuGet package

Code Example

private SteinhartHartCalculatedThermistor thermistor;

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

    thermistor = new SteinhartHartCalculatedThermistor(Device.CreateAnalogInputPort(Device.Pins.A00), new Resistance(10, Meadow.Units.Resistance.UnitType.Kiloohms));

    var consumer = SteinhartHartCalculatedThermistor.CreateObserver(
        handler: result =>
        {
            Resolver.Log.Info($"Temperature New Value {result.New.Fahrenheit:N1}F/{result.New.Celsius:N1}C");
            Resolver.Log.Info($"Temperature Old Value {result.Old?.Fahrenheit:N1}F/{result.Old?.Celsius:N1}C");
        },
        filter: null
    );
    thermistor.Subscribe(consumer);

    thermistor.Updated += (object sender, IChangeResult<Meadow.Units.Temperature> e) =>
    {
        Resolver.Log.Info($"Temperature Updated: {e.New.Fahrenheit:N1}F/{e.New.Celsius:N1}C");
    };

    return Task.CompletedTask;
}

public override async Task Run()
{
    var temp = await thermistor.Read();
    Resolver.Log.Info($"Current temperature: {temp.Fahrenheit:N1}F/{temp.Celsius:N1}C");

    thermistor.StartUpdating(TimeSpan.FromSeconds(1));
}

Sample project(s) available on GitHub

Class Thermistor

Thermistor temperature sensor object

Assembly: Thermistor.dll

View Source

Declaration

public abstract class Thermistor : PollingSensorBase<Temperature>, IObservable<IChangeResult<Temperature>>, ITemperatureSensor, ISamplingSensor<Temperature>, ISensor<Temperature>, ISensor, ISamplingSensor

Inheritance: System.Object -> Meadow.Foundation.ObservableBase<UNIT>

Derived:
Meadow.Foundation.Sensors.Temperature.SteinhartHartCalculatedThermistor

Implements:
System.IObservable<Meadow.IChangeResult<Meadow.Units.Temperature>>, Meadow.Peripherals.Sensors.ITemperatureSensor, Meadow.Peripherals.Sensors.ISamplingSensor<Meadow.Units.Temperature>, Meadow.Peripherals.Sensors.ISensor<Meadow.Units.Temperature>, Meadow.Peripherals.Sensors.ISensor, Meadow.Peripherals.Sensors.ISamplingSensor

Properties

AnalogInputPort

The analog input port used to determine output voltage of the voltage divider circuit

View Source

Declaration

protected IAnalogInputPort AnalogInputPort { get; }

NominalResistance

The nominal resistance of the thermistor (e.g. 10kOhm for a 10k thermistor)

View Source

Declaration

public abstract Resistance NominalResistance { get; }

NominalTemperature

The nominal temperature for the nominal resistance, typically 25C

View Source

Declaration

public virtual Temperature NominalTemperature { get; }

Temperature

The temperature from the last reading

View Source

Declaration

public Temperature? Temperature { get; }

Methods

StartUpdating(TimeSpan?)

Starts updating the sensor on the updateInterval frequency specified.

This method also starts raising Updated events and notifying IObservable subscribers. Use the updateInterval parameter to specify how often events and notifications are raised/sent.

View Source

Declaration

public override void StartUpdating(TimeSpan? updateInterval = null)

Parameters

Type	Name	Description
System.Nullable<System.TimeSpan>	updateInterval	A TimeSpan that specifies how long to

         wait between readings. This value influences how often `*Updated`
         events are raised and `IObservable` consumers are notified.
         The default is 5 seconds. |

StopUpdating()

Stops sampling the sensor

View Source

Declaration

public override void StopUpdating()

Implements

• System.IObservable<Meadow.IChangeResult<Meadow.Units.Temperature>>
• Meadow.Peripherals.Sensors.ITemperatureSensor
• Meadow.Peripherals.Sensors.ISamplingSensor<Meadow.Units.Temperature>
• Meadow.Peripherals.Sensors.ISensor<Meadow.Units.Temperature>
• Meadow.Peripherals.Sensors.ISensor
• Meadow.Peripherals.Sensors.ISamplingSensor