Skip to main content

Meadow.Foundation.Leds.LedBarGraph

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

An LED Bar Graph is packaged array of LEDs commonly used to indicate level or progress and commonly include 8 or 10 leds.

The LedBarGraph class allows you to control an led bar graph using GPIO.

LED bar graphs

Use the SetLed method to turn on or off LEDs individually, or assign a value on the Percentage property to represent it visually on the graph bar, like a battery indicator, temperature, humidity, etc.

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 BAR graph connected to a Meadow F7