Meadow.Foundation.Displays.St7789

St7789
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

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:

• AliExpress
• Ebay
• Amazon

Code Example

MicroGraphics graphics;
St7789 display;

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

    var spiBus = Device.CreateSpiBus();

    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:

Class St7789

Represents a St7789 TFT color display

Assembly: TftSpi.dll

View Source

Declaration

public class St7789 : TftSpiBase, IPixelDisplay, IDisplay, ISpiPeripheral, IDisposable, IRotatableDisplay

Inheritance: System.Object -> Meadow.Foundation.Displays.TftSpiBase

Implements:
Meadow.Peripherals.Displays.IPixelDisplay, Meadow.Peripherals.Displays.IDisplay, Meadow.Hardware.ISpiPeripheral, System.IDisposable, Meadow.Peripherals.Displays.IRotatableDisplay

Properties

DefaultColorMode

The default display color mode

View Source

Declaration

public override ColorMode DefaultColorMode { get; }

SupportedColorModes

The color modes supported by the display

View Source

Declaration

public override ColorMode SupportedColorModes { get; }

DefaultSpiBusSpeed

SPI bus speed

View Source

Declaration

public override Frequency DefaultSpiBusSpeed { get; }

DefaultSpiBusMode

The SPI bus mode for the device

View Source

Declaration

public override SpiClockConfiguration.Mode DefaultSpiBusMode { get; }

Methods

Initialize()

Initialize the display

View Source

Declaration

protected override void Initialize()

SetAddressWindow(int, int, int, int)

Set address window for display updates

View Source

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

SetRotation(RotationType)

Set the display rotation

View Source

Declaration

public void SetRotation(RotationType rotation)

Parameters

Type	Name	Description
Meadow.Peripherals.Displays.RotationType	rotation	The rotation value

Implements

• Meadow.Peripherals.Displays.IPixelDisplay
• Meadow.Peripherals.Displays.IDisplay
• Meadow.Hardware.ISpiPeripheral
• System.IDisposable
• Meadow.Peripherals.Displays.IRotatableDisplay