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Meadow.Foundation.ICs.IOExpanders.Mcp23008

Mcp23008
StatusStatus badge: working
Source codeGitHub
Datasheet(s)GitHub
NuGet packageNuGet Gallery for Meadow.Foundation.ICs.IOExpanders.Mcp23xxx

Code Example

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);
}
}
}

Sample project(s) available on GitHub

Wiring Example

To wire a Mcp23008 to your Meadow board, connect the following:

Mcp23008Meadow Pin
GNDGND
VCC3V3
SCLD08 (SCL Pin)
SDAD07 (SDA Pin)