The Atmega328PB is the greatest thing to come to the Arduino platform since the UNO. Who wouldn't want more 16-bit PWMs and double all 3 serial protocols? The new unofficial Arduino Mini PB Pro! To get the IDE to support it, follow this guide: https://github.com/watterott/ATmega328PB-Testing Since the JSON file is incomplete for Linux, do the manual toolchain replacement. This was a little tricky, and there isn't much on the internet on where the toolchain resides inside the Arduino base folder. Here's what I did to make it work. I downloaded the latest Arduino build, and I will refer to the extracted base directory as "arduino-1.6.9". Also download the "hardware.zip" and the "Arduino Toolchain (4.9.2)" Linux x64 version from the github links. 1. Replace the toolchain The builtin toolchain resides in "arduino-1.6.9/hardware/tools/avr/". Rename the avr folder to "avr.old". Extract the "Arduino Toolc