Remarks

Mcp23017
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Mcp23017 mcp;

public override Task Initialize()
{
    IDigitalInputPort interruptPort = Device.CreateDigitalInputPort(Device.Pins.D00, InterruptMode.EdgeRising);
    IDigitalOutputPort resetPort = Device.CreateDigitalOutputPort(Device.Pins.D01);

    mcp = new Mcp23017(Device.CreateI2cBus(), 0x20, interruptPort, resetPort);

    return base.Initialize();
}

public override Task Run()
{
    while (true)
    {
        TestBulkDigitalOutputPortWrites(20);
        TestDigitalOutputPorts(2);
    }
}

void TestDigitalOutputPorts(int loopCount)
{
    var out00 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA0);
    var out01 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA1);
    var out02 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA2);
    var out03 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA3);
    var out04 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA4);
    var out05 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA5);
    var out06 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA6);
    var out07 = mcp.CreateDigitalOutputPort(mcp.Pins.GPA7);

    var outputPorts = new List<IDigitalOutputPort>() 
    {
        out00, out01, out02, out03, out04, out05, out06, out07
    };

    foreach (var outputPort in outputPorts)
    {
        outputPort.State = true;
    }

    for(int l = 0; l < loopCount; l++) 
    {
        // loop through all the outputs
        for (int i = 0; i < outputPorts.Count; i++) 
        {
            // turn them all off
            foreach (var outputPort in outputPorts) 
            {
                outputPort.State = false; 
            }

            // turn on just one
            outputPorts[i].State = true;
            Thread.Sleep(250);
        }
    }

    // cleanup
    for (int i = 0; i < outputPorts.Count; i++) 
    {
        outputPorts[i].Dispose();
    }
}

void TestBulkDigitalOutputPortWrites(int loopCount)
{
    byte mask = 0x0;

    for (int l = 0; l < loopCount; l++) 
    {
        for (int i = 0; i < 8; i++) 
        {
            mcp.WriteToPorts(mask);
            mask = (byte)(1 << i);
            Thread.Sleep(5);
        }
    }
}

Sample project(s) available on GitHub

Wiring Example

To wire a Mcp23017 to your Meadow board, connect the following:

Mcp23017	Meadow Pin
GND	GND
VCC	3V3
SCL	D08 (SCL Pin)
SDA	D07 (SDA Pin)

Characteristic	Locus
Inheritance	System.Object Mcp23xxx Mcp23x1x > Mcp23017
Inherited Members	Mcp23x1x.Pins Mcp23x1x.NumberOfPins Mcp23x1x.IsValidPin(IPin) Mcp23x1x.GetPin(String) Mcp23xxx.GetAddressFromPins(Boolean, Boolean, Boolean) Mcp23xxx.InputChanged Mcp23xxx._lock Mcp23xxx.ResetMcp() Mcp23xxx.Initialize() Mcp23xxx.CreateDigitalOutputPort(IPin, Boolean, OutputType) Mcp23xxx.CreateDigitalInputPort(IPin) Mcp23xxx.CreateDigitalInputPort(IPin, InterruptMode, ResistorMode) Mcp23xxx.CreateDigitalInputPort(IPin, InterruptMode, ResistorMode, TimeSpan) Mcp23xxx.CreateDigitalInputPort(IPin, InterruptMode, ResistorMode, TimeSpan, TimeSpan) Mcp23xxx.SetPortDirection(IPin, PortDirectionType) Mcp23xxx.WriteToPort(IPin, Boolean) Mcp23xxx.ReadPort(IPin) Mcp23xxx.WriteToPorts(Byte) Mcp23xxx.ReadFromPorts(Mcp23xxx.PortBank) Mcp23xxx.ResetPin(IPin)
Namespace	Meadow.Foundation.ICs.IOExpanders
Assembly	Mcp23xxx.dll

Syntax

public class Mcp23017 : Mcp23x1x

Constructors

Mcp23017(II2cBus, Byte, IDigitalInputPort, IDigitalOutputPort)

Creates an Mcp23017 object

Declaration

public Mcp23017(II2cBus i2cBus, byte address = null, IDigitalInputPort interruptPort = null, IDigitalOutputPort resetPort = null)

Parameters

Type	Name	Description
II2cBus	i2cBus	The I2C bus
System.Byte	address	The I2C address
IDigitalInputPort	interruptPort	The interrupt port
IDigitalOutputPort	resetPort	Optional Meadow output port used to reset the mcp expander