Remarks

St7789
Status Status badge: working
Source code GitHub
Datasheet(s) GitHub
NuGet package NuGet Gallery for Meadow.Foundation.Displays.TftSpi

The ST7789 is a display controller used to drive color displays over SPI using 12, 16 or 18 bbp. These displays require a backlight. These are typically paired with high pixel density displays, the most common being a 1.5" 240x240 display.

ST7789 displays typically use SPI mode 3, but you may find variants that require different modes.

The Meadow.Foundation ST7789 driver currently only supports 16bpp RGB565.

Purchasing

You can get ST7789 displays from the following suppliers:

Code Example

MicroGraphics graphics;
St7789 display;

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

    var config = new SpiClockConfiguration(new Frequency(48000, Frequency.UnitType.Kilohertz), SpiClockConfiguration.Mode.Mode3);
    var spiBus = Device.CreateSpiBus(Device.Pins.SCK, Device.Pins.MOSI, Device.Pins.MISO, config);

    display = new St7789(
        spiBus: spiBus,
        chipSelectPin: Device.Pins.A03,
        dcPin: Device.Pins.A04,
        resetPin: Device.Pins.A05,
        width: 240, height: 240, colorMode: ColorMode.Format16bppRgb565);

    display.Clear(Color.AliceBlue);
    display.Show();

    graphics = new MicroGraphics(display)
    {
        Rotation = RotationType._90Degrees,
        IgnoreOutOfBoundsPixels = true
    };

    return base.Initialize();
}

public override Task Run()
{
    graphics.Clear(true);

    graphics.DrawRectangle(120, 0, 120, 220, Color.White, true);
    graphics.DrawRectangle(0, 0, 120, 20, Color.Red, true);
    graphics.DrawRectangle(0, 20, 120, 20, Color.Purple, true);
    graphics.DrawRectangle(0, 40, 120, 20, Color.Blue, true);
    graphics.DrawRectangle(0, 60, 120, 20, Color.Green, true);
    graphics.DrawRectangle(0, 80, 120, 20, Color.Yellow, true);
    graphics.DrawRectangle(0, 100, 120, 20, Color.Orange, true);

    graphics.Show();

    DisplayTest();

    return base.Run();
}

Sample project(s) available on GitHub

Wiring Example

To wire a ST7789 to your Meadow board, connect the following:

ST7789 Meadow Pin
GND GND
VCC 3V3
SCL SCK
SDA MOSI
RESET D00
DC D01

It should look like the following diagram:

Characteristic Locus
Inheritance System.Object TftSpiBase > St7789
Implements IGraphicsDisplay IRotatableDisplay
Inherited Members TftSpiBase.ColorMode TftSpiBase.Rotation TftSpiBase.Width TftSpiBase.Height TftSpiBase.PixelBuffer TftSpiBase.dataCommandPort TftSpiBase.resetPort TftSpiBase.chipSelectPort TftSpiBase.spiDisplay TftSpiBase.imageBuffer TftSpiBase.readBuffer TftSpiBase.Data TftSpiBase.Command TftSpiBase.IsColorTypeSupported(ColorMode) TftSpiBase.CreateBuffer(ColorMode, Int32, Int32) TftSpiBase.Clear(Boolean) TftSpiBase.Fill(Color, Boolean) TftSpiBase.WriteBuffer(Int32, Int32, IPixelBuffer) TftSpiBase.DrawPixel(Int32, Int32, Boolean) TftSpiBase.DrawPixel(Int32, Int32, Color) TftSpiBase.DrawPixel(Int32, Int32, Byte, Byte, Byte) TftSpiBase.InvertPixel(Int32, Int32) TftSpiBase.Fill(Int32, Int32, Int32, Int32, Color) TftSpiBase.Show() TftSpiBase.Show(Int32, Int32, Int32, Int32) TftSpiBase.Write(Byte) TftSpiBase.Write(Byte[]) TftSpiBase.DelayMs(Int32) TftSpiBase.SendCommand(TftSpiBase.Register) TftSpiBase.SendCommand(TftSpiBase.LcdCommand) TftSpiBase.SendCommand(Byte) TftSpiBase.SendData(Int32) TftSpiBase.SendData(Byte) TftSpiBase.SendData(Byte[]) TftSpiBase.Clear(Color)
Namespace Meadow.Foundation.Displays
Assembly TftSpi.dll

Syntax

public class St7789 : TftSpiBase, IGraphicsDisplay, IRotatableDisplay

Constructors

St7789(ISpiBus, IDigitalOutputPort, IDigitalOutputPort, IDigitalOutputPort, Int32, Int32, ColorMode)

Create a new St7789 color display object

Declaration
public St7789(ISpiBus spiBus, IDigitalOutputPort chipSelectPort, IDigitalOutputPort dataCommandPort, IDigitalOutputPort resetPort, int width, int height, ColorMode colorMode = default(ColorMode))

Parameters

Type Name Description
ISpiBus spiBus

SPI bus connected to display
IDigitalOutputPort chipSelectPort

Chip select output port
IDigitalOutputPort dataCommandPort

Data command output port
IDigitalOutputPort resetPort

Reset output port
System.Int32 width

Width of display in pixels
System.Int32 height

Height of display in pixels
ColorMode colorMode

The color mode to use for the display buffer

St7789(ISpiBus, IPin, IPin, IPin, Int32, Int32, ColorMode)

Create a new St7789 color display object

Declaration
public St7789(ISpiBus spiBus, IPin chipSelectPin, IPin dcPin, IPin resetPin, int width, int height, ColorMode colorMode = default(ColorMode))

Parameters

Type Name Description
ISpiBus spiBus

SPI bus connected to display
IPin chipSelectPin

Chip select pin
IPin dcPin

Data command pin
IPin resetPin

Reset pin
System.Int32 width

Width of display in pixels
System.Int32 height

Height of display in pixels
ColorMode colorMode

The color mode to use for the display buffer

Fields

DefaultSpiBusSpeed

The default SPI bus frequency

Declaration
public static Frequency DefaultSpiBusSpeed

Field Value

Type Description
Frequency

Properties

DefautColorMode

The default display color mode

Declaration
public override ColorMode DefautColorMode { get; }

Property Value

Type Description
ColorMode

Overrides

SupportedColorModes

The color modes supported by the display

Declaration
public override ColorMode SupportedColorModes { get; }

Property Value

Type Description
ColorMode

Overrides

Methods

Initialize()

Initalize the display

Declaration
protected override void Initialize()

Overrides

SetAddressWindow(Int32, Int32, Int32, Int32)

Set addrees window for display updates

Declaration
protected override void SetAddressWindow(int x0, int y0, int x1, int y1)

Parameters

Type Name Description
System.Int32 x0

X start in pixels
System.Int32 y0

Y start in pixels
System.Int32 x1

X end in pixels
System.Int32 y1

Y end in pixels

Overrides

SetRotation(RotationType)

Set the display rotation

Declaration
public void SetRotation(RotationType rotation)

Parameters

Type Name Description
RotationType rotation

The rotation value