ATK-MD0240 LCD Driver (ST7789V)

A no_std driver for the ATK-MD0240 2.4-inch LCD module, which uses the ST7789V controller.

This crate is built upon the embedded-hal traits for hardware abstraction and uses embedded-graphics for all drawing operations.

The driver includes an internal framebuffer to allow for composing graphics before sending a complete frame to the display.

Features

• no_std compatible: Suitable for bare-metal and RTOS-based systems.
• SPI interface for communication.
• embedded-graphics DrawTarget implementation for easy drawing of shapes, text, and images.
• Internal framebuffer (Display2in14) for composing graphics before sending to the display.
• Configurable framebuffer allocation via Cargo features:
  • stack_alloc (default): Allocates the framebuffer on the stack. Simple and no allocator needed.
  • heap_alloc: Allocates the framebuffer on the heap. Requires a global allocator.
• Screen rotation support.

Hardware Connections

The driver requires an SPI interface and three GPIO pins for operation.

LCD Pin	MCU Pin	Description in Code	Description
VCC	3.3V / 5V	-	Power Supply
GND	GND	-	Ground
CS	SPI CS	-	Chip Select (often handled by SpiDevice)
SCLK	SPI SCLK	spi	Serial Clock
SDA/SDI	SPI MOSI	spi	Serial Data In (Master Out)
RESET	GPIO Output	rst	Reset Pin (active low)
RS/DC	GPIO Output	wr	Data/Command Select Pin
BL	GPIO Output	pwr	Backlight Control Pin (active high)

Usage

1. Add to Cargo.toml

Add the following to your Cargo.toml file.

[dependencies]
atk_md0240 = { git = "https://github.com/KaidRommel/ATK-MD0240-rs.git" }

If you need to use heap allocation for the framebuffer, enable the heap_alloc feature.

[dependencies]
atk_md0240 = { git = "https://github.com/KaidRommel/ATK-MD0240-rs.git", features = ["heap_alloc"] }

2. Example

API Overview

• Lcd: The main driver struct. It handles communication with the LCD.
  • init(): Initializes the display controller.
  • clear_frame(): Sends the entire content of a Display2in14 buffer to the screen.
  • set_pixel(): Sets a single pixel on the display (less efficient for multiple pixels).
• Display2in14: An in-memory framebuffer that implements embedded_graphics::DrawTarget.
  • new(): Creates a new framebuffer, filling it with a specified color.
  • clear_buffer(): Clears the buffer to a single color.
  • All embedded-graphics drawing functions can be used on a Display2in14 instance.