This repository contains the source code and configuration files of the Arduino Core for Atmel's SAM3A4C processor (used on the IEEE Tesla Coil MIDI Interrupter board because 2022 chip shortage).
You'll need to add https://raw.githubusercontent.com/ucsbieee/ArduinoCore-SAM3A4C/master/package_TC-controller-3A4C_index.json to the additional boards manager list in Arduino.