blink

A small Hello World Rust application for the AVR.

The program itself toggles a LED on PORTB periodically.

Designed for the ATmega328p.

The AVR-Rust Book

Prerequisites

• A recent version of the nightly Rust compiler. Anything including or greater than rustc 1.63.0-nightly (fee3a459d 2022-06-05) can be used.
• The rust-src rustup component - $ rustup component add rust-src
• AVR-GCC on the system for linking
• AVR-Libc on the system for support libraries

Usage

Now to build, run:

rustup override set nightly

# Ensure time delays are consistent with a 16MHz microcontroller.
export AVR_CPU_FREQUENCY_HZ=16000000

# Compile the crate to an ELF executable.
cargo build -Z build-std=core --target avr-atmega328p.json --release

# Note: there is work in progress to make that easier
#       peeking in .cargo/config.tom  will show that
#            cargo build --release
#       is the short version

There should now be an ELF file at target/avr-atmega328p/release/blink.elf. It can be flashed directly to an AVR microcontroller or ran inside a simulator.

Resources

• The AVR-Rust book