Programming tinyAVR 1-Series Microcontrollers on macOS

27 Feb 2025

I have found myself having to set up this development environment several times and I keep forgetting how to do it easily. Sharing these steps on how to set up the tooling for these new ICs and the other new series of chips.

First, install brew from brew.sh if you don’t have it already, and then install avr-gcc:

brew tap osx-cross/avr
brew install avr-gcc

This installs a recent version of the compiler tools, but lacks libraries and headers for the latest series of microcontrollers. For this, you should clone the official Microchip avr-libc repository:

git clone https://github.com/avrdudes/avr-libc

Now, when you want to compile for a specific IC, you can point your avr-gcc to use the relevant files from the repo you just cloned (replace /path/to/avr-libc with the actual path you cloned to):

avr-gcc \
    -mmcu=attiny412 \
    -I/path/to/avr-libc/include \
    -B/path/to/avr-libc/avr/devices/attiny412 \
    -Wall -Os \
    main.c

And finally you can use avr-objcopy -O ihex a.out main.hex to generate a proper hex file that is ready for flashing.