Meadow.Foundation.Leds.Led

Led
Status
Source code	GitHub
NuGet package

An LED is a diode (a component that attempts to let current flow only one way through it) that emits light when voltage is applied to it. Because it is a diode, it only works when a voltage is applied in one direction.

LEDs commonly have one lead longer (the Cathode) than the other (the Anode). The longer cathode leg indicates that it should be connected to the positive (+) side of a circuit.

Code Example

LedBarGraph ledBarGraph;

public override Task Initialize()
{
    Resolver.Log.Info("Initializing...");

    // Using an array of Pins 
    IPin[] pins =
    {
         Device.Pins.D11,
         Device.Pins.D10,
         Device.Pins.D09,
         Device.Pins.D08,
         Device.Pins.D07,
         Device.Pins.D06,
         Device.Pins.D05,
         Device.Pins.D04,
         Device.Pins.D03,
         Device.Pins.D02
    };

    ledBarGraph = new LedBarGraph(pins);

    return Task.CompletedTask;
}

public override async Task Run()
{
    Resolver.Log.Info("TestLedBarGraph...");

    float percentage = 0;

    while (true)
    {
        Resolver.Log.Info("Turning them on and off for 200ms using SetLed...");
        for (int i = 0; i < ledBarGraph.Count; i++)
        {
            await ledBarGraph.SetLed(i, true);
            await Task.Delay(100);
            await ledBarGraph.SetLed(i, false);
        }

        await Task.Delay(1000);

        Resolver.Log.Info("Turning them on using Percentage...");
        while (percentage < 1)
        {
            percentage += 0.10f;
            await ledBarGraph.SetPercentage(Math.Min(1.0f, percentage));
            await Task.Delay(100);
        }

        await Task.Delay(1000);

        Resolver.Log.Info("Turning them off using Percentage...");
        while (percentage > 0)
        {
            percentage -= 0.10f;
            await ledBarGraph.SetPercentage(Math.Max(0.0f, percentage));
            await Task.Delay(100);
        }

        await Task.Delay(1000);

        Resolver.Log.Info("Charging animation...");
        while (percentage < 1)
        {
            percentage += 0.10f;
            await ledBarGraph.SetPercentage(Math.Min(1.0f, percentage));
            await ledBarGraph.StartBlink(ledBarGraph.GetTopLedForPercentage());
            await Task.Delay(2000);
        }

        await Task.Delay(1000);

        Resolver.Log.Info("Discharging animation...");
        while (percentage > 0)
        {
            percentage -= 0.10f;
            await ledBarGraph.SetPercentage(Math.Max(0.0f, percentage));
            await ledBarGraph.StartBlink(ledBarGraph.GetTopLedForPercentage());
            await Task.Delay(2000);
        }

        await Task.Delay(1000);

        Resolver.Log.Info("Blinking for 5 seconds at 500ms on/off...");
        await ledBarGraph.StartBlink();
        await Task.Delay(5000);
        await ledBarGraph.StopAnimation();

        await Task.Delay(1000);

        Resolver.Log.Info("Blinking for 5 seconds at 200ms on/off...");
        await ledBarGraph.StartBlink(TimeSpan.FromMilliseconds(200), TimeSpan.FromMilliseconds(200));
        await Task.Delay(5000);
        await ledBarGraph.StopAnimation();

        await Task.Delay(1000);
    }
}

Sample project(s) available on GitHub

Wiring Example

Class Led

Utility functions to provide blinking for Led

Assembly: Meadow.Foundation.dll

View Source

Declaration

public class Led : ILed, IDisposable

Implements:
Meadow.Peripherals.Leds.ILed, System.IDisposable

Properties

IsOn

Turns on LED with current color or turns it off

View Source

Declaration

public bool IsOn { get; set; }

Port

Gets the port that is driving the LED

View Source

Declaration

protected IDigitalOutputPort Port { get; set; }

IsDisposed

Is the object disposed

View Source

Declaration

public bool IsDisposed { get; }

Methods

StopAnimation()

Stops the current LED animation

View Source

Declaration

public Task StopAnimation()

Returns

System.Threading.Tasks.Task

StartBlink()

Start the Blink animation which sets turns the LED on and off on an interval of 1 second (500ms on, 500ms off)

View Source

Declaration

public Task StartBlink()

Returns

System.Threading.Tasks.Task

StartBlink(TimeSpan, TimeSpan)

Start the Blink animation which sets turns the LED on and off with the specified durations

View Source

Declaration

public Task StartBlink(TimeSpan onDuration, TimeSpan offDuration)

Returns

System.Threading.Tasks.Task

Parameters

Type	Name	Description
System.TimeSpan	onDuration	The duration the LED stays on
System.TimeSpan	offDuration	The duration the LED stays off

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

View Source

Declaration

public void Dispose()

Dispose(bool)

Dispose of the object

View Source

Declaration

protected virtual void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	Is disposing

Implements

• Meadow.Peripherals.Leds.ILed
• System.IDisposable