Embedded Rust XKCD viewer. Displays a random XKCD on a LCD or OLED display.

It is written in Rust, using the no_std library, in adherence to the principles described in the ESP-RS book. This repository is based on esp-jokes-rs.

What is challenging about this is that the image we're displaying might not fit in RAM (400K on esp32c3, but less is available for our code), and sometimes neither does the input file. The incremental-png library was created to address this. It's focused in incremental decoding and minimizing memory usage.

esp-xkcd running on esp32c2 with SSD1306 display, showing XKCD #2846
Original image license: CC BY-NC 2.5

• Displays XKCD image
• Written in Rust, showcasing how to use the no_std library for ESP32 development.
• Supports various display drivers, including ST7735 and SSD1306

Hardware options are selected using Cargo features. Some are selected by default. To change the configuration pass --no-default-features --features <your_features>.

Boards:

• esp32c3
• esp32c6

Displays:

• display-st7735
• display-ssd1306

To build in the default mode (ESP32C3, ST7735), simply run:

cargo run

For example, to build on ESP32C6 with SSD1306 display, use the following command:

cargo run --no-default-features --features esp32c6,display-ssd1306

To get started with this project, you will need:

• An ESP32 development board (See Supported hardware configurations above for which boards are supported)
• An OLED or LCD display connected to your ESP32.
• Rust and the associated toolchain installed on your development machine.

Follow these steps to set up and run the project:

1. Clone this repository to your development machine.

   git clone https://github.com/jborkowski/esp-jokes-rs.git

2. Change the working directory to the project folder.

   cd esp-jokes-rs

3. Build the project using Cargo, the Rust package manager.

   cargo build

4. Flash the resulting binary to your ESP32 board.

   cargo run

   Note: You might need additional options here depending on your hardware configuration, see Supported hardware configurations.

5. Once the flashing process is complete, ESP board will connect to WiFi and display the image. Enjoy!

• src/ contains the Rust source code for the project.
• Cargo.toml is the configuration file for the project, where dependencies and build options are specified.

We welcome contributions to this project. If you have ideas for more improvements or want to add features, feel free to open an issue or a pull request.

This project is licensed under the MIT License - see the LICENSE file for details.

• This project is based on the Wokwi example project, and we are grateful for the inspiration it provided.

• Jonatan Borkowski
• Maciej Bielecki

Special thanks to the ESP32 community, the Rust programming language developers, and everyone who contributed to the libraries and tools used in this project.