added generic potentiometer

Source/Meadow.Foundation.Core/Sensors/Potentiometer/Potentiometer.cs

@@ -0,0 +1,109 @@
+using Meadow.Hardware;
+using Meadow.Units;
+using System;
+
+namespace Meadow.Foundation.Sensors;
+
+/// <summary>
+/// Represents a potentiometer - a variable resistor that can be measured through an analog input.
+/// Implements both IPotentiometer and IDisposable interfaces.
+/// </summary>
+public class Potentiometer : IPotentiometer, IDisposable
+{
+    private IAnalogInputPort inputPort;
+    private Voltage referenceVoltage;
+    private bool portCreated = false;
+
+    /// <summary>
+    /// Gets whether this instance has been disposed.
+    /// </summary>
+    public bool IsDisposed { get; private set; }
+
+    /// <summary>
+    /// Gets the maximum resistance value of the potentiometer.
+    /// </summary>
+    public Resistance MaxResistance { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the Potentiometer class with default reference voltage.
+    /// </summary>
+    /// <param name="inputPort">The input port to read the potentiometer value from.</param>
+    /// <param name="maxResistance">The maximum resistance value of the potentiometer.</param>
+    public Potentiometer(IAnalogInputPort inputPort, Resistance maxResistance)
+    {
+        this.inputPort = inputPort;
+        MaxResistance = maxResistance;
+        referenceVoltage = inputPort.ReferenceVoltage;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the Potentiometer class with default reference voltage.
+    /// </summary>
+    /// <param name="inputPin">The input pin to read the potentiometer value from.</param>
+    /// <param name="maxResistance">The maximum resistance value of the potentiometer.</param>
+    public Potentiometer(IPin inputPin, Resistance maxResistance)
+    {
+        inputPort = inputPin.CreateAnalogInputPort(1);
+        MaxResistance = maxResistance;
+        referenceVoltage = inputPort.ReferenceVoltage;
+        portCreated = true;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the Potentiometer class with a specified reference voltage.
+    /// </summary>
+    /// <param name="inputPin">The input pin to read the potentiometer value from.</param>
+    /// <param name="maxResistance">The maximum resistance value of the potentiometer.</param>
+    /// <param name="referenceVoltage">The reference voltage used for analog-to-digital conversion.</param>
+    public Potentiometer(IPin inputPin, Resistance maxResistance, Voltage referenceVoltage)
+    {
+        inputPort = inputPin.CreateAnalogInputPort(1);
+        MaxResistance = maxResistance;
+        this.referenceVoltage = referenceVoltage;
+        portCreated = true;
+    }
+
+    /// <summary>
+    /// Gets the current resistance value of the potentiometer by reading the analog input.
+    /// Setting the resistance throws NotSupportedException as potentiometer value can only be changed mechanically.
+    /// </summary>
+    /// <exception cref="NotSupportedException">Thrown when attempting to set the resistance value.</exception>
+    public Resistance Resistance
+    {
+        get
+        {
+            var adcVoltage = inputPort.Read().Result;
+            return new Resistance(MaxResistance.Ohms * adcVoltage.Volts / referenceVoltage.Volts);
+        }
+        set
+        {
+            throw new NotSupportedException("Standard potentiometer resistance is set mechanically");
+        }
+    }
+
+    /// <summary>
+    /// Releases the unmanaged resources used by the Potentiometer and optionally releases the managed resources.
+    /// </summary>
+    /// <param name="disposing">True to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
+    protected virtual void Dispose(bool disposing)
+    {
+        if (!IsDisposed)
+        {
+            if (disposing)
+            {
+                if (portCreated) inputPort.Dispose();
+            }
+            IsDisposed = true;
+        }
+    }
+
+    /// <summary>
+    /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+    /// </summary>
+    public void Dispose()
+    {
+        // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+        Dispose(disposing: true);
+        GC.SuppressFinalize(this);
+    }
+}