These board files are required to compile the firmware for the SensorDots Port MuxR
Install at least version 1.8.6 of Arduino or later (this is required for the latest board manager tools to install).
Add the following URL to the Arduino Boards Manager (File->Preferences):
https://raw.githubusercontent.com/sensordots/PortMuxRBoard/master/package_m328pb_index.json
Update the Arduino AVR Boards to version 1.6.22 or higher via the Boards Manager (Tools->Boards->Boards Manager). This is important, otherwise the sketch won't compile.
Install the "SensorDots Port MuxR" board via the Boards Manager (Tools->Boards->Boards Manager).
To compile just select SensorDots Port MuxR as the board to build against and the appropriate COM port.
1.1.3 - Initial release based off version 1.1.3 of the https://github.com/watterott/ATmega328PB-Testing libraries.