Remarks

Apa102
Status Status badge: working
Source code GitHub
Datasheet(s) GitHub
NuGet package NuGet Gallery for Meadow.Foundation.Leds.Apa102

Code Example

Apa102 apa102;
int numberOfLeds = 256;
float maxBrightness = 0.25f;

public override Task Initialize()
{
    Resolver.Log.Info("Initialize...");
    apa102 = new Apa102(Device.CreateSpiBus(Apa102.DefaultSpiBusSpeed), numberOfLeds, Apa102.PixelOrder.BGR);

    return base.Initialize();
}

public override Task Run()
{
    apa102.Clear();

    apa102.SetLed(index: 0, color: Color.Red, brightness: 0.5f);
    apa102.SetLed(index: 1, color: Color.Purple, brightness: 0.6f);
    apa102.SetLed(index: 2, color: Color.Blue, brightness: 0.7f);
    apa102.SetLed(index: 3, color: Color.Green, brightness: 0.8f);
    apa102.SetLed(index: 4, color: Color.Yellow, brightness: 0.9f);
    apa102.SetLed(index: 5, color: Color.Orange, brightness: 1.0f);

    apa102.Show();

    Apa102Tests();

    return Task.CompletedTask;
}

Sample project(s) available on GitHub

Wiring Example

To wire a Apa102 to your Meadow board, connect the following:

Apa102 Meadow Pin
GND GND
CI SCK
DI MOSI
VCC 5V

It should look like the following diagram:

Characteristic Locus
Inheritance System.Object > Apa102
Implements IApa102 IGraphicsDisplay IPixelBuffer
Namespace Meadow.Foundation.Leds
Assembly Apa102.dll

Syntax

public class Apa102 : object, IApa102, IGraphicsDisplay, IPixelBuffer

Constructors

Apa102(ISpiBus, IPin, Int32, Apa102.PixelOrder)

Creates a new APA102 object

Declaration
public Apa102(ISpiBus spiBus, IPin chipSelectPin, int numberOfLeds, Apa102.PixelOrder pixelOrder = Apa102.PixelOrder.BGR)

Parameters

Type Name Description
ISpiBus spiBus

SPI bus
IPin chipSelectPin

Chip select pin
System.Int32 numberOfLeds

Number of leds
Apa102.PixelOrder pixelOrder

Pixel color order

Apa102(ISpiBus, IPin, Int32, Int32, Apa102.PixelOrder)

Creates a new APA102 object

Declaration
public Apa102(ISpiBus spiBus, IPin chipSelectPin, int width, int height, Apa102.PixelOrder pixelOrder = Apa102.PixelOrder.BGR)

Parameters

Type Name Description
ISpiBus spiBus

SPI bus
IPin chipSelectPin

Chip select pin
System.Int32 width

Width of led array
System.Int32 height

Height of led array
Apa102.PixelOrder pixelOrder

Pixel color order

Apa102(ISpiBus, Int32, Apa102.PixelOrder, IDigitalOutputPort)

Creates a new APA102 object

Declaration
public Apa102(ISpiBus spiBus, int numberOfLeds, Apa102.PixelOrder pixelOrder = Apa102.PixelOrder.BGR, IDigitalOutputPort chipSelectPort = null)

Parameters

Type Name Description
ISpiBus spiBus

SPI bus
System.Int32 numberOfLeds

Number of leds
Apa102.PixelOrder pixelOrder

Pixel color order
IDigitalOutputPort chipSelectPort

SPI chip select port (optional)

Apa102(ISpiBus, Int32, Int32, Apa102.PixelOrder, IDigitalOutputPort)

Creates a new APA102 object

Declaration
public Apa102(ISpiBus spiBus, int width, int height, Apa102.PixelOrder pixelOrder = Apa102.PixelOrder.BGR, IDigitalOutputPort chipSelectPort = null)

Parameters

Type Name Description
ISpiBus spiBus

SPI bus
System.Int32 width

Width of led array
System.Int32 height

Height of led array
Apa102.PixelOrder pixelOrder

Pixel color order
IDigitalOutputPort chipSelectPort

SPI chip select port (optional)

Fields

DefaultSpiBusSpeed

Default SPI bus speed

Declaration
public static Frequency DefaultSpiBusSpeed

Field Value

Type Description
Frequency

spiPeripheral

SpiPeripheral object

Declaration
protected ISpiPeripheral spiPeripheral

Field Value

Type Description
ISpiPeripheral

Properties

BitDepth

The color bit depth of the display

Declaration
public int BitDepth { get; }

Property Value

Type Description
System.Int32

Brightness

Brightness used for LEDs Default is 0.5

Declaration
public float Brightness { get; set; }

Property Value

Type Description
System.Single

Buffer

The display buffer - not implemented for the Apa102 driver

Declaration
public byte[] Buffer { get; }

Property Value

Type Description
System.Byte[]

ByteCount

The size of the display buffer in bytes

Declaration
public int ByteCount { get; }

Property Value

Type Description
System.Int32

ColorMode

Color mode of leds - 24bpp

Declaration
public ColorMode ColorMode { get; }

Property Value

Type Description
ColorMode

Height

Height of pixel array

Declaration
public int Height { get; }

Property Value

Type Description
System.Int32

NumberOfLeds

Total number of leds

Declaration
public int NumberOfLeds { get; }

Property Value

Type Description
System.Int32

PixelBuffer

PixelBuffer representation of the Apa102

Declaration
public IPixelBuffer PixelBuffer { get; }

Property Value

Type Description
IPixelBuffer

SupportedColorModes

The Color mode supported by the display

Declaration
public ColorMode SupportedColorModes { get; }

Property Value

Type Description
ColorMode

Width

Width of pixel array

Declaration
public int Width { get; }

Property Value

Type Description
System.Int32

Methods

Clear()

Clear the display buffer

Declaration
public void Clear()

Clear(Boolean)

Clear the display buffer

Declaration
public void Clear(bool update = false)

Parameters

Type Name Description
System.Boolean update

Update the leds if true

DrawPixel(Int32, Int32, Color)

Draw pixel at location

Declaration
public void DrawPixel(int x, int y, Color color)

Parameters

Type Name Description
System.Int32 x

x position of pixel
System.Int32 y

y position of pixel
Color color

color of pixel

DrawPixel(Int32, Int32, Boolean)

Draw pixel at a location Primarily used for monochrome displays, prefer overload that accepts a Color

Declaration
public void DrawPixel(int x, int y, bool enabled)

Parameters

Type Name Description
System.Int32 x

x position of pixel
System.Int32 y

y position of pixel
System.Boolean enabled

if true draw white, if false draw black

Fill(Color)

Fill the display buffer with a color

Declaration
public void Fill(Color color)

Parameters

Type Name Description
Color color

The fill color

Fill(Color, Boolean)

Fill the entire display buffer with a color

Declaration
public void Fill(Color clearColor, bool updateDisplay = false)

Parameters

Type Name Description
Color clearColor

color to fill
System.Boolean updateDisplay

update after fill

Fill(Int32, Int32, Int32, Int32, Color)

Fill a color in the specified region

Declaration
public void Fill(int x, int y, int width, int height, Color fillColor)

Parameters

Type Name Description
System.Int32 x

x position
System.Int32 y

y position
System.Int32 width

width to fill
System.Int32 height

height to fill
Color fillColor

color to fill

GetPixel(Int32, Int32)

Get the color of pixel at at given coordinate

Declaration
public Color GetPixel(int x, int y)

Parameters

Type Name Description
System.Int32 x

X position in pixels
System.Int32 y

Y position in pixels

Returns

Type Description
Color

InvertPixel(Int32, Int32)

Invert pixel at location

Declaration
public void InvertPixel(int x, int y)

Parameters

Type Name Description
System.Int32 x

x position of pixel
System.Int32 y

y position of pixel

SetLed(Int32, Color)

Set the color of the specified LED using the global brightness balue

Declaration
public virtual void SetLed(int index, Color color)

Parameters

Type Name Description
System.Int32 index

Index of the LED to change
Color color

The color

SetLed(Int32, Color, Single)

Set the color of the specified LED

Declaration
public virtual void SetLed(int index, Color color, float brightness = 1F)

Parameters

Type Name Description
System.Int32 index

Index of the LED to change
Color color

The color
System.Single brightness

The brighrness 0.0 - 1.0f

SetLed(Int32, Byte[])

Set the color of the specified LED

Declaration
public virtual void SetLed(int index, byte[] rgb)

Parameters

Type Name Description
System.Int32 index

Index of the LED to change
System.Byte[] rgb

Byte array representing the color RGB values. byte[0] = Red, byte[1] = Green, byte[2] = Blue

SetLed(Int32, Byte[], Single)

Set the color of the specified LED

Declaration
public virtual void SetLed(int index, byte[] rgb, float brightness = 1F)

Parameters

Type Name Description
System.Int32 index

Index of the LED to change
System.Byte[] rgb

Byte array representing the color RGB values. byte[0] = Red, byte[1] = Green, byte[2] = Blue
System.Single brightness

The brighrness 0.0 - 1.0f

SetPixel(Int32, Int32, Color)

Set the pixel for a given coordindate

Declaration
public void SetPixel(int x, int y, Color color)

Parameters

Type Name Description
System.Int32 x

X position in pixels
System.Int32 y

Y position in pixels
Color color

Color of pixel

Show()

Transmit the buffer to the LEDs

Declaration
public void Show()

Show(Int32, Int32, Int32, Int32)

Update APA102 with data in display buffer

Declaration
public void Show(int left, int top, int right, int bottom)

Parameters

Type Name Description
System.Int32 left

left
System.Int32 top

top
System.Int32 right

right
System.Int32 bottom

bottom

WriteBuffer(Int32, Int32, IPixelBuffer)

Draw a buffer at the specified location

Declaration
public void WriteBuffer(int x, int y, IPixelBuffer displayBuffer)

Parameters

Type Name Description
System.Int32 x

x position
System.Int32 y

y position
IPixelBuffer displayBuffer

buffer to draw