Multi touch interface (part 3): The LED frame

Today I was starting with the LED frame to illuminate the acrylic panel. As I wrote before, for the prototype I’m using a couple of shape “L” aluminium profiles, 90cm each (the plexyglass widh is 70cm, but I toke 90cm to use as a bracket over the trestles). I will put 25 IR LEDs on each profile.

I still didn’t any test, but the firts thing I worried about is the aluminium I bought. I have natural aluminium, but it’s possible that I will need polished aluminium to reflect better the possible light leaks throught the panel. Anyway this is only for the prototype, with the finished project I will use shape “U” polished aluminium profiles to wrap the LEDs completely.

I have a 3cm distance between each LED, and I will mount them in a manner that when we have an “space” between 2 LEDs, we have a LED on the other profile, covering all non illuminated parts of the frame:

0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0

   0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0 

I printed a template of that to put it on the profiles and have the exactly marks where I have to drill the holes.

The LEDs thickness is 5mm, so I will use, obviously, a metal drill bit to do the holes. I will put then the LEDs as in the next pic (casually my rules has a 5mm hole on it).

The assembly will be as in the pic underneath. I haven’t drilled yet, so the pic doesn’t show the LEDs, but you can see how it will look like:

Tomorrow I will start the drilling, I’m waiting for the cables (I will use non-soldering cables while I don’t adjust all the system, but it’s recommendable to solder the electronics at the end).