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Meadow.Foundation.Leds.Led

Led
StatusStatus badge: working
Source codeGitHub
NuGet packageNuGet Gallery for Meadow.Foundation

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

Circuit layout sample showing an LED connected through a resistor to pin D08 and ground on a Meadow F7