restructured the project to have each interface in one folder.

src/Microsoft.PowerShell.IoT/Gpio/Get/GetGpioPin.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections;
+using System.Management.Automation;  // PowerShell namespace.
+
+ [Cmdlet(VerbsCommon.Get, "GpioPin")]
+public class GetGpioPin : Cmdlet
+{
+	[Parameter(Mandatory = false, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, Position = 0)]
+	public int[] Id { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true, Position = 1)]
+	public PullMode? PullMode { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true)]
+	public SwitchParameter Raw { get; set; }
+
+	protected override void ProcessRecord()
+	{
+		try
+		{
+			ArrayList pinList = new ArrayList();
+
+			if ((this.Id == null) || (this.Id.Length <= 0))
+			{
+				foreach (var pin in Unosquare.RaspberryIO.Pi.Gpio.Pins)
+				{
+					pinList.Add(pin.PinNumber);
+				}
+			}
+			else
+			{
+				pinList.AddRange(this.Id);
+			}
+
+			foreach (int pinId in pinList)
+			{
+				var pin = Unosquare.RaspberryIO.Pi.Gpio[pinId];
+				try
+				{
+					pin.PinMode = Unosquare.RaspberryIO.Gpio.GpioPinDriveMode.Input;
+					if (this.PullMode.HasValue)
+					{
+						pin.InputPullMode = (Unosquare.RaspberryIO.Gpio.GpioPinResistorPullMode)this.PullMode.Value;
+					};
+				}
+				catch (System.NotSupportedException)
+				{
+					// We want to avoid errors like
+					// System.NotSupportedException : Get - GpioPin : Pin Pin15 'BCM 14 (UART Transmit)' does not support mode 'Input'.Pin capabilities are limited to: UARTTXD
+					// at the same time we need to return PinInfo for such pins, so we need to continue processing
+				}
+				bool pinBoolValue = pin.Read();
+
+				if (this.Raw)
+				{
+					WriteObject(pinBoolValue ? SignalLevel.High : SignalLevel.Low);
+				}
+				else
+				{
+					GpioPinData pinData = new GpioPinData(pinId, pinBoolValue ? SignalLevel.High : SignalLevel.Low, pin);
+					WriteObject(pinData);
+				}
+			}
+		}
+		catch (System.TypeInitializationException e) // Unosquare.RaspberryIO.Gpio.GpioController.Initialize throws this TypeInitializationException
+		{
+			if (!Unosquare.RaspberryIO.Computer.SystemInfo.Instance.IsRunningAsRoot)
+			{
+				throw new PlatformNotSupportedException(Resources.ErrNeedRootPrivileges, e);
+			}
+			throw;
+		}
+	}
+}
+
+ public enum PullMode
+{
+	Off = 0,
+	PullDown = 1,
+	PullUp = 2
+}

src/Microsoft.PowerShell.IoT/Gpio/GpioPinData.cs

@@ -0,0 +1,19 @@
+ public class GpioPinData
+{
+	public int Id;
+	public SignalLevel Value;
+	//public Unosquare.RaspberryIO.Gpio.GpioPin PinInfo; //not in use
+
+	public GpioPinData(int id, SignalLevel value, Unosquare.RaspberryIO.Gpio.GpioPin pinInfo)
+	{
+		this.Id = id;
+		this.Value = value;
+		//this.PinInfo = pinInfo;
+	}
+}
+
+public enum SignalLevel
+{
+	Low = 0,
+	High = 1
+}

src/Microsoft.PowerShell.IoT/Gpio/Set/SetGpioPin.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Management.Automation;  // PowerShell namespace.
+
+[Cmdlet(VerbsCommon.Set, "GpioPin")]
+public class SetGpioPin : Cmdlet
+{
+	[Parameter(Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, Position = 0)]
+	public int[] Id { get; set; }
+
+	[Parameter(Mandatory = true, ValueFromPipelineByPropertyName = true, Position = 1)]
+	public SignalLevel Value { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true)]
+	public SwitchParameter PassThru { get; set; }
+
+	protected override void ProcessRecord()
+	{
+		try
+		{
+			if (this.Id != null)
+			{
+				foreach (int pinId in this.Id)
+				{
+					var pin = Unosquare.RaspberryIO.Pi.Gpio[pinId];
+					pin.PinMode = Unosquare.RaspberryIO.Gpio.GpioPinDriveMode.Output;
+					pin.Write((Unosquare.RaspberryIO.Gpio.GpioPinValue)this.Value);
+					if (this.PassThru)
+					{
+						GpioPinData pinData = new GpioPinData(pinId, this.Value, pin);
+						WriteObject(pinData);
+					}
+				}
+			}
+		}
+		catch (System.TypeInitializationException e) // Unosquare.RaspberryIO.Gpio.GpioController.Initialize throws this TypeInitializationException
+		{
+			if (!Unosquare.RaspberryIO.Computer.SystemInfo.Instance.IsRunningAsRoot)
+			{
+				throw new PlatformNotSupportedException(Resources.ErrNeedRootPrivileges, e);
+			}
+			throw;
+		}
+	}
+}

src/Microsoft.PowerShell.IoT/I2c/Get/GetI2cDevice.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Management.Automation;  // PowerShell namespace.
+using System.Device.I2c;
+
+[Cmdlet(VerbsCommon.Get, "I2CDevice")]
+public class GetI2CDevice : Cmdlet
+{
+	[Parameter(Mandatory = true, ValueFromPipelineByPropertyName = true, Position = 0)]
+	public int Id { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true, Position = 1)]
+	public string FriendlyName { get; set; }
+
+	public GetI2CDevice()
+	{
+		this.FriendlyName = string.Empty;
+		this.Id = 0;
+	}
+
+	protected override void ProcessRecord()
+	{
+		var settings = new I2cConnectionSettings(1, this.Id);
+		I2cDevice device = I2cDevice.Create(settings);
+		WriteObject(new I2CDevice(device, this.Id, this.FriendlyName));
+
+	}
+}

src/Microsoft.PowerShell.IoT/I2c/Get/GetI2cRegister.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Management.Automation;  // PowerShell namespace.
+[Cmdlet(VerbsCommon.Get, "I2CRegister")]
+public class GetI2CRegister : Cmdlet
+{
+	[Parameter(Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, Position = 0)]
+	public I2CDevice Device { get; set; }
+
+	[Parameter(Mandatory = true, ValueFromPipelineByPropertyName = true, Position = 1)]
+	public ushort Register { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true, Position = 2)]
+	public byte ByteCount { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true)]
+	public SwitchParameter Raw { get; set; }
+
+	public GetI2CRegister()
+	{
+		this.ByteCount = 1;
+		this.Raw = false;
+	}
+
+	protected override void ProcessRecord()
+	{
+		if (this.ByteCount > 1)
+		{
+			byte[] writeBuffer = new byte[] { (byte)this.Register };
+			Span<byte> readBuffer = stackalloc byte[ByteCount];
+
+			this.Device.device.Read(readBuffer);
+
+			if (this.Raw)
+			{
+				WriteObject(readBuffer.ToArray());
+			}
+			else
+			{
+				I2CDeviceRegisterData result = new I2CDeviceRegisterData(this.Device, this.Register)
+				{
+					Data = readBuffer.ToArray() // optimize to be Span? How does PowerShell deal with it?
+				};
+				WriteObject(result);
+			}
+		}
+		else
+		{
+			this.Device.device.WriteByte((byte)this.Register);
+			byte value = this.Device.device.ReadByte();
+			//byte value = this.Device.device.ReadAddressByte(this.Register);
+			if (this.Raw)
+			{
+				WriteObject(value);
+			}
+			else
+			{
+				I2CDeviceRegisterData result = new I2CDeviceRegisterData(this.Device, this.Register, new byte[1] { value });
+				WriteObject(result);
+			}
+		}
+	}
+}

src/Microsoft.PowerShell.IoT/I2c/I2cDevice.cs

@@ -0,0 +1,26 @@
+public class I2CDevice
+{
+	internal System.Device.I2c.I2cDevice device = null;
+
+	public string FriendlyName { get; set; }
+	public int Id { get; set; }
+
+	public I2CDevice(System.Device.I2c.I2cDevice device, int Id, string FriendlyName)
+	{
+		this.device = device;
+		this.Id = Id;
+		this.FriendlyName = FriendlyName;
+	}
+
+	public override string ToString()
+	{
+		if (string.IsNullOrEmpty(this.FriendlyName))
+		{
+			return this.Id.ToString();
+		}
+		else
+		{
+			return this.FriendlyName;
+		}
+	}
+}

src/Microsoft.PowerShell.IoT/I2c/I2cRegisterData.cs

@@ -0,0 +1,23 @@
+public class I2CDeviceRegisterData
+{
+	public I2CDevice Device { get; set; }
+	public ushort Register { get; set; }
+	public byte[] Data { get; set; }
+
+	public I2CDeviceRegisterData(I2CDevice device, ushort register, byte[] data)
+	{
+		this.Device = device;
+		this.Register = register;
+		this.Data = data;
+	}
+
+	public I2CDeviceRegisterData(I2CDevice device, ushort register)
+		: this(device, register, new byte[0])
+	{
+	}
+
+	public I2CDeviceRegisterData()
+		: this(null, 0)
+	{
+	}
+}

src/Microsoft.PowerShell.IoT/I2c/Set/SetI2cRegister.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Management.Automation;  // PowerShell namespace.
+
+[Cmdlet(VerbsCommon.Set, "I2CRegister")]
+public class SetI2CRegister : Cmdlet
+{
+	[Parameter(Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, Position = 0)]
+	public I2CDevice Device { get; set; }
+
+	[Parameter(Mandatory = true, ValueFromPipelineByPropertyName = true, Position = 1)]
+	public ushort Register { get; set; }
+
+	[Parameter(Mandatory = true, ValueFromPipelineByPropertyName = true, Position = 2)]
+	public byte[] Data { get; set; }
+
+	[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true)]
+	public SwitchParameter PassThru { get; set; }
+
+	protected override void ProcessRecord()
+	{
+		Span<byte> dataOut = stackalloc byte[] { (byte)Register, Data[0] };
+		this.Device.device.Write(dataOut);
+		if (this.PassThru)
+		{
+			I2CDeviceRegisterData result = new I2CDeviceRegisterData(this.Device, this.Register, this.Data);
+			WriteObject(result);
+		}
+	}
+}