mini multitouch

Since Im working at Plymouth this summer i needed to build a demo multitouch unit that could fit in a suitcase. So to fit the bill i made a small 18x24 inch multitouch screen that is designed to fold into a suitcase and sit on a desktop next to a laptop.



I didn't want to hassle with getting another psu unit or bringing one to england so i picked up a couple of battery holders from radioshack and linked them together. Each holds 4 AA batteries so 2 battery holders in series kicks out 12v dc. Since the LEDs only run at about 100ma that should give me a good 10 hours of continuous use but they come with a built in switch to i can just switch it off when I'm not using.

The other great advantage to having it on the desktop is that it makes software development so much easier. I can edit the actionscript then turn on the multitouch and test the results without having to get up and move over the screen on the other side of the room.

Even with only 16 LEDs the blob sensitivity is excellent. In fact due to lack of time i didn't have time to sand down the edges of the acrylic but that did not make ay appreciable difference to the blob resolution at least at this scale. Although for the larger screen with the web cam further away i imagine it would make a noticeable difference.