This is all the Arduino code for the book in a single repository, unlike the Java code, the Arduino one is very compact, and it would make little sense to separate it in different repositories. It also includes the libraries used for the projects.
There are a series of examples, mostly the full listings for the book plus a couple of debug tools we used while writing it. On top of that there are three libraries: the USB Host library, based on the one published on the Arduino website; the P2PMQTT one, our own way to get a minimal communication protocol to send data between devices in a broker free infrastructure; and a library to control long lines of LEDs strongly based on one by Adafruit Industries (thanks Limor!).
This code was written by Andreas G�ransson and David Cuartielles for a book called Android Open Accessory Programming with Arduino.