The matching probability, which is calculated based on users' profiles, is displayed as a color code using this RGB LED. See more in the design and prototyping document.
We are getting closer to complete the first prototype of the Matchmaking Device System. The video below shows two Arduino Uno boards exchanging data via an IR transceiver. In fact, we used a proximity sensor made of an IR LED and photoresistor. Therefore, this very low cost proximity sensor plays a dual role, to detect another matchmaking device in proximity and to communicate with it. For communication we will use the protocols developed for IR remote controls (like in your TV remote control).