XMOS will be part of the avionic module of the rocket. More technically, it's going to take data from several captors (accelerometer, barometer, gyroscope, GPS coordinates, etc) and it's going to calculate results such as (landing position, parachute releasing, etc). It's also gonna send us precious data back to ground with an XTEND. This will allow us to see interesting data in real time on our computer screen while the rocket will be in the air.
The rocket isn't finished yet, but mighty engineers are working on it. They have released interesting pictures of their work on the rocket nosecone