Welcome to the Rust Bindings for rpi_ws281x

This project is going through major overhauls, so expect breaking changes on most version changes.

API Design - Help Wanted

Please take a look at the feature-new-api branch and issue #1 and give some feedback!

Usage

Currently in major flux, more details when I finish the "Stage 1" overhaul. The current version on crates.io is pretty close to a bare bindgen wrap of the C library. The next version will look a lot more like typical Rust, inspired by the efforts of @Meh who wrote manual bindings to this libray a while back.

Contributing

Code is licensed under the MIT license, so as long as you are cool with that, feel free to open an issue, talk about proposed changes, then open a PR! I would love a helping hand, just have to make sure things don't get too messy either.

Compiling on Raspbian

• Install Rust from https://rustup.rs/
• Run rustup target add arm-unknown-linux-gnueabihf
• Install sudo apt install libclang-dev

Cross-compiling on Windows

• Make sure Git is installed. This is used to clone the latest rpi-ws2811 lib.
• Download and install libclang from [LLVM]; 32-bit for Windows
• Download and install GCC for the Raspberry Pi.
• Using rustup, install the 32-bit GCC Rust toolchain and set as default:
  • rustup default stable-i686-pc-windows-gnu
• Add the Raspberry Pi architecture target to the GCC toolchain:
  • For all Raspberry Pi versions:
  • rustup target add arm-unknown-linux-gnueabihf
  • For an optimized Raspberry Pi 3 target (the ARMv7 architecture):
  • rustup target add armv7-unknown-linux-gnueabihf

• At the root of your Rust project, create a new directory and name it .cargo. Inside that directory, create a file and paste the contents:

  • ``` [build] target = "arm-unknown-linux-gnueabihf"

    [target.arm-unknown-linux-gnueabihf] linker = "C:/SysGCC/raspberry/bin/arm-linux-gnueabihf-gcc.exe" ```

  • This informs Rust/Cargo to always use the arm-unknown-linux-gnueabihf target (so that --target doesn't always have to be passed to cargo) and so that the GCC linker for the given architecture is used.
  • Be sure to change the linker path or the target architecture if you installed the GCC ARM toolset in a different directory or are using the ARMv7 target instead.
• It is suggested to create a build script so that the necessary environment variables can be set. This library needs to know where to find the GCC toolset in order to cross compile the rpi-ws2811 C library for the Raspberry Pi.

An example build script might look like this (using Git for Windows Bash):

```

!/usr/bin/env bash

inform rpi-ws2811-rust where the GCC sysroot is

export RPIWS281XSYSROOT=C:/SysGCC/raspberry/arm-linux-gnueabihf/sysroot

point to the GCC ARM compiler/linker.

export CCarmunknownlinuxgnueabihf=C:/SysGCC/raspberry/bin/arm-linux-gnueabihf-gcc.exe

point to the GCC ARM archiver

export ARarmunknownlinuxgnueabihf=C:/SysGCC/raspberry/bin/arm-linux-gnueabihf-ar.exe

run the build command

cargo build $@ ```