lvgl-rs/README.md

2.3 KiB

LittlevGL - Open-source Embedded GUI Library in Rust

Original LittlevGL demo image

LittlevGL provides everything you need to create a Graphical User Interface (GUI) on embedded systems with easy-to-use graphical elements, beautiful visual effects and low memory footprint.

LittlevGL is compatible with #![no_std] environments by default.

Official LittlevGL Website · C library repository · Live demo


Rust bindings usage demo code.

Usage

Edit your Cargo.toml file dependencies with:

$ cargo add lvgl

The build requires the environment variable bellow to be set:

  • DEP_LV_CONFIG_PATH: Path to the directory containing the lv_conf.h header file used for configuration of LittlevGL library.

We recommend the lv_conf.h file to be in your project's root directory. If so, the command to build your project would be:

$ DEP_LV_CONFIG_PATH=`pwd` cargo build

Building for embedded environments

We make use of bindgen for generating the bindings to LittlevGL at build time. There is a problem in cargo when building for no_std, so we need to use a workaround to build "lvgl-rs". The mainstrem issue in cargo is being tracked at rust-lang/cargo#7915.

$ DEP_LV_CONFIG_PATH=`pwd` cargo build -Zfeatures=build_dep

Requirements / Limitations

LittlevGL C libary do allocate memory dynamically and we need to allocate memory on the heap in the Rust side as well (Box). That is required, so we can safely provide Rust pointers through FFI. For that reason, we do require alloc module to be available.

Running the demo

This project contains examples that can run in a desktop simulator.

First, make sure to pull lvgl-rs submodules:

$ git submodule init
$ git submodule update 

Then run the demo example:

$ DEP_LV_CONFIG_PATH=`pwd`/examples/include cargo run --example demo