ST7735 Display Driver

This crate provides an async driver for the ST7735 display controller, implementing the Panel trait to be used with the display-driver crate.

Usage

This driver is designed to work with the display-driver crate. You can use the DisplayDriver struct to drive the display.

1. Choose a Spec

The ST7735 has many variations (often distinguished by "Tab" colors in other libraries). This crate provides Generic types that map to these common variations.

2. Implementation Example

use display_driver::{ColorFormat, DisplayDriver, Orientation, LCDResetOption};
// The `Spec` (Generic128x160Type1) defines the hardware-specific constants (Gamma, Voltage).
use display_driver_st7735::{St7735, spec::generic::Generic128x160Type1};

// 1. Configure Reset
let reset_opt = LCDResetOption::new_pin(reset_pin);

// 2. Create the Panel instance using a Generic Spec (e.g., Generic128x160Type1)
let panel = St7735::<Generic128x160Type1, _, _>::new(reset_opt);

// 3. Bind Bus and Panel, Configure, and Initialize
// The driver orchestrates the logic, delegating transport to 'bus' and commands to 'panel'.
let mut display = DisplayDriver::builder(bus, panel)
    .with_color_format(ColorFormat::RGB565)
    // This framework automatically handles offsets.
    .with_orientation(Orientation::Deg90)
    .init(&mut delay).await.unwrap();

// Now you can use `display` to draw:
display.write_frame(fb).await.unwrap();

Full examples can be found at examples

Specs

Because ST7735 panels come in various resolutions, offsets, and color formats, we use a Spec trait.

• Generic Specs: Pre-defined configurations for common panel variations (found in spec::generic).
• Vendor Specs: Specific implementations for known physical display modules (found in spec::vendor_specs).

You can also define your own Spec by implementing the St7735Spec trait if your panel has unique requirements.

Mapping Table

The following table maps the provided Generic types to common names used in the Adafruit and TFT_eSPI libraries, as well as specific vendor implementations present in this crate.

Implementing a Custom Spec

If the built-in Generic or Vendor specs don't match your display (e.g., incorrect offsets, colors inverted, different Gamma curve), you can define your own.

[!TIP] You can use the impl_st7735_initr! macro to use standard "InitR" values (common parameters from Adafruit_ST7735) for the complex registers.

use display_driver_st7735::{PanelSpec, St7735Spec, impl_st7735_initr};

// 1. Define your type
pub struct MyCustomPanel;

// 2. Configure Resolution & Offsets
impl PanelSpec for MyCustomPanel {
    const PHYSICAL_WIDTH: u16 = 128;
    const PHYSICAL_HEIGHT: u16 = 160;

    // Panel Offset
    const PHYSICAL_X_OFFSET: u16 = 2;
    const PHYSICAL_Y_OFFSET: u16 = 1;

    // Optional Panel offset in pixels when the screen is rotated 180° or 270°.
    // Used for panels that are not physically centered within the frame.
    // If undefined, defaults to PHYSICAL_X_OFFSET / PHYSICAL_Y_OFFSET.
    const PHYSICAL_X_OFFSET_ROTATED: u16 = 2;
    const PHYSICAL_Y_OFFSET_ROTATED: u16 = 3;

    // Set true if colors are inverted (White is Black)
    const INVERTED: bool = true; 
    // Set true if Red and Blue are swapped (BGR Order)
    const BGR: bool = true; 
}

// 3. Implement St7735Spec
// Option A: Use default "InitR" sequence (Easiest)
impl_st7735_initr!(MyCustomPanel);

// Option B: manual implementation (Advanced)
// Include Gamma, Power, Frame Rate etc.
// impl St7735Spec for MyCustomPanel {
//      ... define const FRMCTR1_PARAMS, etc.
// }

License

This project is under Apache License, Version 2.0 (LICENSE or http://www.apache.org/licenses/LICENSE-2.0).