µPad uses the RIOT operating system to satisfy its real-time constraints. Therefore, before building µPad, the RIOT source must be installed. Instructions for downloading and installing RIOT are outside the scope of this manual. RIOT does not maintain a stable interface, but µPad is known to work with the following commit:
commit fc4fd6222fc5ca0bb843dc2bb0e7e55335138802 Author: José Ignacio Alamos <email@example.com> Date: Thu Jun 1 11:48:23 2017 -0400 pkg/openthread: Add tests
Later commits will probably also work. You will also need to install the tool-chain corresponding to your chosen controller board. For details refer to the RIOT website http://www.riot-os.org.
Other requirements are
You must install all of the software mentioned above before attempting to build or install µPad.