Meadow.Foundation.ICs.IOExpanders.Mcp23xxx 2.5.0

Meadow.Foundation.ICs.IOExpanders.Mcp23xxx

Mcp23xxx I2C and SPI digital output expanders

The Mcp23xxx library is included in the Meadow.Foundation.ICs.IOExpanders.Mcp23xxx nuget package and is designed for the Wilderness Labs Meadow .NET IoT platform.

This driver is part of the Meadow.Foundation peripherals library, an open-source repository of drivers and libraries that streamline and simplify adding hardware to your C# .NET Meadow IoT applications.

For more information on developing for Meadow, visit developer.wildernesslabs.co.

To view all Wilderness Labs open-source projects, including samples, visit github.com/wildernesslabs.

Installation

You can install the library from within Visual studio using the the NuGet Package Manager or from the command line using the .NET CLI:

dotnet add package Meadow.Foundation.ICs.IOExpanders.Mcp23xxx

Usage

private Mcp23008 mcp;

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

    mcp = new Mcp23008(Device.CreateI2cBus(), 0x20, interruptPort, resetPort);

    return base.Initialize();
}

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

private void BenchmarkDigitalOutputPorts()
{
    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
    };

    var state = false;
    var stopwatch = new Stopwatch();
    Resolver.Log.Info("Starting benchmark");

    for (var x = 0; x < 10; x++)
    {
        stopwatch.Restart();
        for (var iteration = 0; iteration < 100; iteration++)
        {
            for (var i = 0; i < outputPorts.Count; i++)
            {
                outputPorts[i].State = state;
            }

            state = !state;
        }
        stopwatch.Stop();

        Resolver.Log.Info($"{100 * outputPorts.Count} pins toggled in {stopwatch.ElapsedMilliseconds}ms");
    }

    Resolver.Log.Info("Benchmark finished");
}

private 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();
    }
}

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);
        }
    }
}
        

How to Contribute

• Found a bug? Report an issue
• Have a feature idea or driver request? Open a new feature request
• Want to contribute code? Fork the Meadow.Foundation repository and submit a pull request against the develop branch

Need Help?

If you have questions or need assistance, please join the Wilderness Labs community on Slack.

About Meadow

Meadow is a complete, IoT platform with defense-grade security that runs full .NET applications on embeddable microcontrollers and Linux single-board computers including Raspberry Pi and NVIDIA Jetson.

Build

Use the full .NET platform and tooling such as Visual Studio and plug-and-play hardware drivers to painlessly build IoT solutions.

Connect

Utilize native support for WiFi, Ethernet, and Cellular connectivity to send sensor data to the Cloud and remotely control your peripherals.

Deploy

Instantly deploy and manage your fleet in the cloud for OtA, health-monitoring, logs, command + control, and enterprise backend integrations.