A no-std Rust driver for HUB75-style LED matrix panels on ESP32-series microcontrollers. HUB75 is a standard interface for driving large, bright, and colorful RGB LED displays, commonly used in digital signage and art installations.

This library provides a high-performance implementation that uses Direct Memory Access (DMA) to drive the display with minimal CPU overhead. It is designed to work with a variety of ESP32 models, using the most efficient peripheral available on each chip:

• ESP32-S3: Uses the LCD_CAM peripheral
• ESP32-C6: Uses the PARL_IO peripheral
• ESP32: Uses the I2S peripheral in parallel mode

The driver is built on top of the embedded-graphics crate, allowing you to easily draw shapes, text, and images on the display. It also uses a zero-copy framebuffer for efficient memory usage.

• An ESP32-series microcontroller (ESP32, ESP32-S3, or ESP32-C6)
• A HUB75 LED matrix panel
• A 5V power supply capable of providing several amps of current
• A 3.3V to 5V level shifter (e.g., 74HCT245) is highly recommended

Note: The ESP32 operates at 3.3V, while HUB75 panels require 5V logic signals. While it may sometimes work without one, using a level shifter ensures reliable operation and prevents damage to your hardware.

This driver supports two types of HUB75 pin configurations, which you can select based on your hardware setup:

• Hub75Pins16 (Direct Drive): This is the standard configuration where the row address lines are sent with every pixel. It requires more GPIO pins but works with any standard HUB75 panel.

• Hub75Pins8 (Latched): This configuration is for controller boards that include an external 74HC574-style latch for the row address lines. This is more memory-efficient and requires fewer GPIO pins. For more details on the required circuit, see the hub75-framebuffer crate's documentation or its GitHub repository.

The following examples demonstrate how to use this crate with different ESP32 variants.

• examples/hello_lcd_cam - Displays "Hello, World!".
• examples/lcd_cam.rs - Shows a color gradient and stats.

• examples/hello_parl_io.rs - Displays "Hello, World!".
• examples/parl_io.rs - Shows a color gradient and stats.

• examples/hello_i2s_parallel.rs - Displays "Hello, World!".
• examples/i2s_parallel.rs - Shows a color gradient and stats.

• esp32: Enable support for the ESP32
• esp32s3: Enable support for the ESP32-S3
• esp32c6: Enable support for the ESP32-C6
• defmt: Enable logging with defmt
• log: Enable logging with the log crate
• invert-blank: Invert the blank signal, required for some controller boards.
• skip-black-pixels: Forwards to the hub75-framebuffer crate, enabling an optimization that skips writing black pixels to the framebuffer.

This project is dual-licensed under either of the following:

• Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

We welcome contributions! Please feel free to submit a Pull Request.

By contributing, you agree that your submissions will be licensed under both the Apache-2.0 and MIT licenses.

If you need help, please open an issue on our GitHub repository.