Remarks

Mcp23s08
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

Mcp23s08 mcp;

public override Task Initialize()
{
    IDigitalInputPort interruptPort = Device.CreateDigitalInputPort(Device.Pins.D00, InterruptMode.EdgeRising);
    IDigitalOutputPort chipSelectPort = Device.CreateDigitalOutputPort(Device.Pins.D01);
    IDigitalOutputPort resetPort = Device.CreateDigitalOutputPort(Device.Pins.D02);

    mcp = new Mcp23s08(Device.CreateSpiBus(), chipSelectPort, 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.GP0);
    var out01 = mcp.CreateDigitalOutputPort(mcp.Pins.GP1);
    var out02 = mcp.CreateDigitalOutputPort(mcp.Pins.GP2);
    var out03 = mcp.CreateDigitalOutputPort(mcp.Pins.GP3);
    var out04 = mcp.CreateDigitalOutputPort(mcp.Pins.GP4);
    var out05 = mcp.CreateDigitalOutputPort(mcp.Pins.GP5);
    var out06 = mcp.CreateDigitalOutputPort(mcp.Pins.GP6);
    var out07 = mcp.CreateDigitalOutputPort(mcp.Pins.GP7);

    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 Mcp23s08 to your Meadow board, connect the following:

Mcp23s08	Meadow Pin
GND	GND
VCC	3V3
SCL	D08 (SCL Pin)
SDA	D07 (SDA Pin)

Characteristic	Locus
Inheritance	System.Object Mcp23xxx Mcp23x0x > Mcp23s08
Inherited Members	Mcp23x0x.Pins Mcp23x0x.NumberOfPins Mcp23x0x.IsValidPin(IPin) Mcp23x0x.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 Mcp23s08 : Mcp23x0x

Constructors

Mcp23s08(ISpiBus, IDigitalOutputPort, IDigitalInputPort, IDigitalOutputPort)

Creates an Mcp23s08 object

Declaration

public Mcp23s08(ISpiBus spiBus, IDigitalOutputPort chipSelectPort, IDigitalInputPort interruptPort = null, IDigitalOutputPort resetPort = null)

Parameters

Type	Name	Description
ISpiBus	spiBus	The SPI bus
IDigitalOutputPort	chipSelectPort	Chip select port
IDigitalInputPort	interruptPort	optional interupt port, needed for input interrupts
IDigitalOutputPort	resetPort	Optional Meadow output port used to reset the mcp expander

Mcp23s08(ISpiBus, IPin, IPin)

Creates an Mcp23s08 object

Declaration

public Mcp23s08(ISpiBus spiBus, IPin chipSelectPin, IPin interruptPin = null)

Parameters

Type	Name	Description
ISpiBus	spiBus	The SPI bus
IPin	chipSelectPin	Chip select pin
IPin	interruptPin	optional interupt pin, needed for input interrupts (InterruptMode: EdgeRising, ResistorMode.InternalPullDown)