Class PwmLedBarGraph | Meadow.Foundation API website

Remarks

LedBarGraph
Status
Source code	GitHub
NuGet package

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

The PwmLedBarGraph class allows you to control an led bar graph using PWM ports.

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

The following example shows how to use the intanciate a PwmLedBarGraph witn an array of PWM ports, and turn on/off leds individually, make the entire bar blink and pulse:

public class MeadowApp : App<F7Micro, MeadowApp>
{
    PwmLedBarGraph pwmLedBarGraph;

    public MeadowApp()
    {
        Console.WriteLine("Initializing...");

        // Using an array of IPwmPorts
        IPwmPort[] ports =
        {
                Device.CreatePwmPort(Device.Pins.D04),
                Device.CreatePwmPort(Device.Pins.D05),
                Device.CreatePwmPort(Device.Pins.D06),
                Device.CreatePwmPort(Device.Pins.D07),
                Device.CreatePwmPort(Device.Pins.D08),
                Device.CreatePwmPort(Device.Pins.D09),
                Device.CreatePwmPort(Device.Pins.D10),
                Device.CreatePwmPort(Device.Pins.D11),
                Device.CreatePwmPort(Device.Pins.D12),
                Device.CreatePwmPort(Device.Pins.D13)
        };
        pwmLedBarGraph = new PwmLedBarGraph(ports, 0.25f);            

        TestPwmLedBarGraph();
    }

    protected void TestPwmLedBarGraph()
    {
        Console.WriteLine("TestLedBarGraph...");

        float percentage = 0;

        while (true)
        {
            Console.WriteLine("Turning them on using SetLed...");
            for (int i = 0; i < pwmLedBarGraph.Count; i++)
            {
                pwmLedBarGraph.SetLed(i, true);
                Thread.Sleep(300);
            }

            Thread.Sleep(1000);

            Console.WriteLine("Turning them off using SetLed...");
            for (int i = pwmLedBarGraph.Count - 1; i >= 0; i--)
            {
                pwmLedBarGraph.SetLed(i, false);
                Thread.Sleep(300);
            }

            Thread.Sleep(1000);

            Console.WriteLine("Turning them on using Percentage...");
            while (percentage <= 1)
            {
                percentage += 0.01f;
                pwmLedBarGraph.Percentage = Math.Min(1.0f, percentage);
                Thread.Sleep(100);
            }

            Thread.Sleep(1000);

            Console.WriteLine("Turning them off using Percentage...");
            while (percentage >= 0)
            {
                percentage -= 0.01f;
                pwmLedBarGraph.Percentage = Math.Max(0.0f, percentage);
                Thread.Sleep(100);
            }

            Thread.Sleep(1000);

            Console.WriteLine("Bar blinking on and off...");
            pwmLedBarGraph.StartBlink();
            Thread.Sleep(3000);
            pwmLedBarGraph.Stop();

            Thread.Sleep(1000);

            Console.WriteLine("Bar pulsing...");
            pwmLedBarGraph.StartPulse();
            Thread.Sleep(3000);
            pwmLedBarGraph.Stop();

            Thread.Sleep(1000);
        }
    }
}

Sample projects available on GitHub

Wiring Example

Characteristic	Locus
Inheritance	System.Object > PwmLedBarGraph
Inherited Members	System.Object.ToString() System.Object.Equals(System.Object) System.Object.Equals(System.Object, System.Object) System.Object.ReferenceEquals(System.Object, System.Object) System.Object.GetHashCode() System.Object.GetType() System.Object.MemberwiseClone()
Namespace	Meadow.Foundation.Leds
Assembly	Meadow.Foundation.dll

Syntax

public class PwmLedBarGraph

Constructors

PwmLedBarGraph(IIODevice, IPin[], Single)

Create an LedBarGraph instance from an array of IPwnPin and a forwardVoltage for all LEDs in the bar graph

Declaration

public PwmLedBarGraph(IIODevice device, IPin[] pins, float forwardVoltage)

Parameters

Type	Name	Description
IIODevice	device
IPin[]	pins
System.Single	forwardVoltage

PwmLedBarGraph(IPwmPort[], Single)

Create an LedBarGraph instance from an array of IDigitalOutputPort

Declaration

public PwmLedBarGraph(IPwmPort[] ports, float forwardVoltage)

Parameters

Type	Name	Description
IPwmPort[]	ports
System.Single	forwardVoltage

Fields

pwmLeds

Declaration

protected PwmLed[] pwmLeds

Field Value

Type	Description
PwmLed[]

Properties

Count

The number of the LEDs in the bar graph

Declaration

public int Count { get; }

Property Value

Type	Description
System.Int32

Percentage

Declaration

public float Percentage { get; set; }

Property Value

Type	Description
System.Single

Methods

GetTopLedForPercentage()

Returns the index of the last LED turned on

Declaration

public uint GetTopLedForPercentage()

Returns

Type	Description
System.UInt32

SetLed(UInt32, Boolean)

Set the LED state

Declaration

public void SetLed(uint index, bool isOn)

Parameters

Type	Name	Description
System.UInt32	index	index of the LED
System.Boolean	isOn

SetLedBlink(UInt32, UInt32, UInt32, Single, Single)

Starts a blink animation on an individual LED

Declaration

public void SetLedBlink(uint index, uint onDuration = 200U, uint offDuration = 200U, float highBrightness = 1F, float lowBrightness = 0F)

Parameters

Type	Name	Description
System.UInt32	index
System.UInt32	onDuration
System.UInt32	offDuration
System.Single	highBrightness
System.Single	lowBrightness

SetLedBrightness(UInt32, Single)

Set the brightness of an individual LED when using PWM

Declaration

public void SetLedBrightness(uint index, float brightness)

Parameters

Type	Name	Description
System.UInt32	index
System.Single	brightness

SetLedPulse(UInt32, UInt32, Single, Single)

Starts a pulse animation on an individual LED

Declaration

public void SetLedPulse(uint index, uint pulseDuration = 600U, float highBrightness = 1F, float lowBrightness = 0.15F)

Parameters

Type	Name	Description
System.UInt32	index
System.UInt32	pulseDuration
System.Single	highBrightness
System.Single	lowBrightness

StartBlink(UInt32, UInt32, Single, Single)

Start the Blink animation which sets the brightness of the LED alternating between a low and high brightness setting, using the durations provided.

Declaration

public void StartBlink(uint onDuration = 200U, uint offDuration = 200U, float highBrightness = 1F, float lowBrightness = 0F)

Parameters

Type	Name	Description
System.UInt32	onDuration	On duration.
System.UInt32	offDuration	Off duration.
System.Single	highBrightness	High brigtness.
System.Single	lowBrightness	Low brightness.

StartPulse(UInt32, Single, Single)

Start the Pulse animation which gradually alternates the brightness of the LED between a low and high brightness setting, using the durations provided. Pulse duration. High brigtness. Low brightness.

Declaration

public void StartPulse(uint pulseDuration = 600U, float highBrightness = 1F, float lowBrightness = 0.15F)

Parameters

Type	Name	Description
System.UInt32	pulseDuration
System.Single	highBrightness
System.Single	lowBrightness

Stop()

Stops any running animations.

Declaration

public void Stop()