The new Trigger/GPS module for the extreme energy events project

The Extreme Energy Event (EEE) project is an experiment devoted to the study of high energy Extensive Air Showers (EAS) over a very large area, using an array of muon telescopes. At present the array is composed of more than 50 stations, most of them distributed across the Italian territory, on a total area of around 3×105km2. The telescopes are based on position-sensitive Multi-gap Resistive Plate Chambers (MRPCs) whose readout strips are connected to two TDC (Time-to-Digital Converter) units. Here a novel VME trigger unit for the EEE telescopes is presented, which also includes an embedded GPS receiver for precision timing applications. This new unit gets together, in the same electronic board, the functionalities of different parts of the electronics used up to now in the EEE experiment, and adds new ones, making the whole readout system simpler, more flexible and robust. Details about the trigger/GPS unit, including some measurements of its time resolution, are reported here.