Jawa Droid caller

One of the Charity Dalek's group wears a Jawa costume and has a Droid caller. I thought it would be a great idea to produce a Droid caller that actually works so went about designing and building a Droid caller that is unique to the R6 series Droids. Things that need adding are a belt clip and lense over the LED's.
When the green button is hit and the device pointed at the R6 a number of things can happen. Currently when the device is pointed at the R6 a sound is emmitted. The LED's in the device trigger an optical switch which in turn triggers a sound.
What I have also been working on is other actions being triggered from the Droid caller.
When the green button is pressed a bright red light is emmitted but when held the LED's pulse. This will trigger a secondary action via a second sensor set up to detect a pulsing light. I am not sure what the action could be as yet but it could even be a power of to the head action making the droid look like it has gone to sleep.