#773 Using rust on the RPi

Installing rust on a Raspberry Pi and using it for GPIO programming, also test cross-compilation from macOS to Raspberry Pi.

Build

Notes

Installing the Rust Toolchain

For the latest info, see https://www.rust-lang.org/tools/install

Using the remote self-installer:

pi@raspi1:~ $ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
...

  stable-arm-unknown-linux-gnueabihf installed - rustc 1.86.0 (05f9846f8 2025-03-31)


Rust is installed now. Great!

To get started you may need to restart your current shell.
This would reload your PATH environment variable to include
Cargo's bin directory ($HOME/.cargo/bin).

To configure your current shell, you need to source
the corresponding env file under $HOME/.cargo.

This is usually done by running one of the following (note the leading DOT):
. "$HOME/.cargo/env"            # For sh/bash/zsh/ash/dash/pdksh
source "$HOME/.cargo/env.fish"  # For fish
source "$HOME/.cargo/env.nu"    # For nushell

So far so good - looks like we are good to go!

Blinky Test Circuit Design

Let’s do a simple blinky with an LED on GPIO23:

schematic

Making a simple Blinky Circuit

Creating a new app the standard cargo way:

pi@raspi1:~ $ . "$HOME/.cargo/env"
pi@raspi1:~ $ cargo new blinky
    Creating binary (application) `blinky` package
note: see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
pi@raspi1:~ $ cd blinky
pi@raspi1:~/blinky $ cargo run
   Compiling blinky v0.1.0 (/home/pi/blinky)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 18.31s
     Running `target/debug/blinky`
Hello, world!

For GPIO control, we need the rust_gpiozero crate.

pi@raspi1:~/blinky $ cargo add rust_gpiozero

I’ve added a simple blinky script in main.rs

extern crate rust_gpiozero;

use rust_gpiozero::*;
use std::thread::sleep;
use std::time::Duration;

fn main() {
    let led = LED::new(23);

    loop {
        println!("on");
        led.on();
        sleep(Duration::from_secs(1));
        println!("off");
        led.off();
        sleep(Duration::from_secs(1));
    }
}

Testing

Running from the Raspberry Pi with cargo run and it is blinking at 1Hz:

bb_build

Cross-compiling on macOS

Its all very well being able to compile on the Raspberry Pi itself. But since my prime machine is macOS, can I cross-compile on macOS for deployment on Raspberry Pi?

There’s not a great deal of definitive information available, but I finally got things going after finding https://t-shaped.nl/cross-compiling-rust-programs-for-a-raspberry-pi-from-macos.

Install arm-linux-gnueabihf-binutils and add the armv7-unknown-linux-musleabihf target:

cd blinky
brew install arm-linux-gnueabihf-binutils
rustup target add armv7-unknown-linux-musleabihf

Add linker hint to ~/.cargo/config.toml

$ cat ~/.cargo/config.toml
[target.armv7-unknown-linux-musleabihf]
linker = "arm-linux-gnueabihf-ld"

Now can I build?

$ cargo build --target=arm-unknown-linux-musleabi
   Compiling libc v0.2.172
   Compiling lazy_static v1.5.0
   Compiling rppal v0.12.0
   Compiling rust_gpiozero v0.2.1
   Compiling blinky v0.1.0 (/Users/paulgallagher/MyGithub/tardate/LittleArduinoProjects/RaspberryPi/rust/blinky)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.55s

Yes! Now copy to the Pi:

scp target/arm-unknown-linux-musleabi/debug/blinky pi@raspi1.local:blinky-xc

And execute on the Raspberry Pi:

pi@raspi1:~ $ ./blinky-xc
on
off
on
off
on
off
on
off
on
off
on
off
^C
pi@raspi1:~ $

Building a release version and copy to the Pi:

$ cargo build --release --target=arm-unknown-linux-musleabi
   Compiling libc v0.2.172
   Compiling lazy_static v1.5.0
   Compiling rppal v0.12.0
   Compiling rust_gpiozero v0.2.1
   Compiling blinky v0.1.0 (/Users/paulgallagher/MyGithub/tardate/LittleArduinoProjects/RaspberryPi/rust/blinky)
    Finished `release` profile [optimized] target(s) in 1.58s

$ scp target/arm-unknown-linux-musleabi/release/blinky pi@raspi1.local:blinky-xc-release

On the Pi:

pi@raspi1:~ $ ./blinky-xc-release
on
off
on
off
on
^C
pi@raspi1:~ $

Perfect!

Project Notes