Meadow.Foundation.ICs.IOExpanders.Mcp23018

Mcp23018
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

private Mcp23018 mcp;

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

    mcp = new Mcp23018(Device.CreateI2cBus(), 0x20, interruptPort, resetPort);

    return base.Initialize();
}

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

private 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();
    }
}

private 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 Mcp23018 to your Meadow board, connect the following:

Mcp23018	Meadow Pin
GND	GND
VCC	3V3
SCL	D08 (SCL Pin)
SDA	D07 (SDA Pin)

Class Mcp23018

Represent an MCP23018 I2C port expander with open-drain outputs

Assembly: Mcp23xxx.dll

View Source

Declaration

public class Mcp23018 : Mcp23x1x, IDigitalInputOutputController, IDigitalInputController, IDigitalOutputController, ISpiPeripheral, II2cPeripheral, IDigitalInterruptController, IPinController

Inheritance: System.Object -> Meadow.Foundation.ICs.IOExpanders.Mcp23xxx

Implements:
Meadow.Hardware.IDigitalInputOutputController, Meadow.Hardware.IDigitalInputController, Meadow.Hardware.IDigitalOutputController, Meadow.Hardware.ISpiPeripheral, Meadow.Hardware.II2cPeripheral, Meadow.Hardware.IDigitalInterruptController, Meadow.Hardware.IPinController

Methods

CreateDigitalOutputPort(IPin, bool)

Creates a new DigitalOutputPort using the specified pin and initial state

View Source

Declaration

public IDigitalOutputPort CreateDigitalOutputPort(IPin pin, bool initialState = false)

Returns

Meadow.Hardware.IDigitalOutputPort: IDigitalOutputPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin number to create the port on
System.Boolean	initialState	Whether the pin is initially high or low

CreateDigitalOutputPort(IPin, bool, OutputType)

Creates a new DigitalOutputPort using the specified pin and initial state

View Source

Declaration

public override IDigitalOutputPort CreateDigitalOutputPort(IPin pin, bool initialState = false, OutputType outputType = OutputType.OpenDrain)

Returns

Meadow.Hardware.IDigitalOutputPort: IDigitalOutputPort

Parameters

Type	Name	Description
Meadow.Hardware.IPin	pin	The pin number to create the port on
System.Boolean	initialState	Whether the pin is initially high or low
Meadow.Hardware.OutputType	outputType	The output type

Implements

• Meadow.Hardware.IDigitalInputOutputController
• Meadow.Hardware.IDigitalInputController
• Meadow.Hardware.IDigitalOutputController
• Meadow.Hardware.ISpiPeripheral
• Meadow.Hardware.II2cPeripheral
• Meadow.Hardware.IDigitalInterruptController
• Meadow.Hardware.IPinController