Interactive LED- iLED 1.0

So the purpose of this project was to decorate my walls with something a little more exciting than your standard run of the mill prints or pictures. I wanted an interactive painting that anybody could play with. Most of the inspiration for this project came from the Electro-Graph made by the Graffiti Research Lab. And, of course, much inspiration was taken from the origonal Lite-Brite. Anyway, on to the worklog.

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The materials for this project were all ordered online with the exception of the paint and metal sheeting, which i got at Home Depot. I ordered 100 10mm LEDS from this great manufacturer in china. Even with $23 shipping they were cheaper than anywhere I found locally or online. I ended up getting 20 red, blue, green, yellow, and white.

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Before actually starting on the circuit I wanted to draw it out one last time and make sure my copper tape would actually hold a current and light up an LED.

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With most of the materials I needed in hand I started working on the circuit. The first step was to cut the alluminum sheet to the size i wanted: 17 x 21. With the alluminum cut I spraypainted it matt black and let it dry. Once dry I was ready to start laying out the copper tape. I drew out the pattern on a piece of paper so I had something to use as a reference.

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I Started with the 2 vertical strips that would be the lead wires that the AC power supply fed into. They would be the trunks that all the strips came off of. With those down I started applying the strips of tape from left to right keeping the pieces of copper close to eachother but not actually touching. The idea is that they never touch and the circuit is only bridged when an LED is placed across the 2 pieces of tape.

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After I had about a quarter of the alluminum covered I stopped to test the conductivity. I attached 2 AA batteries to the circuit and it lit up the LED beautifully. Success!

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I finished laying the rest of the tape and noticed I had poor conductivity across the entire board. I determined that this was due to bad contacts where the strips of tape met the “trunks” on either side. So, to remedy this I got out my souldering iron and put a bead of soulder connecting each strip to it’s respective trunk. After souldering the entire thing I went to test it and it didnt work at all. Nothing would light up. Apparantly the heat from the souldering iron had melted the glue under the copper that had, untill now, been acting to insulate the copper and keep it from shorting across the metal sheet. Fuck.

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So it was time to start all over. Luckily I bought enough metal for a second try. This time I cut the metal to the size of a cheap picture frame I had laying around. I took the balsa wood backing out of the picture frame and glued it to the sheet of metal using my trusty 3M spray fixitive. I decided to keep the metal behind the balsa wood and attach the copper to the wood this time. The rare earth magnets are plenty powerful enough to attach to stick to the metal through the thin balsa wood.

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After glueing, spraying, and sanding I was ready to start laying the tape again. This time I tested the current after each piece of tape to make sure there were no shorts and that I was keeping enough current to power the LEDs.

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I was able to keep enough current with the tape alone over about a quarter of the board, but after that it was lost to too many bad connections. Not wanting to ruin this attempt like i had the last one I decided to try a less perminant method of maintaining the current. I simply took a piece of copper tape, turned it upside down, and taped it across the “trunks”. This seemed to work perfectly and kept a good connection to all points along the length of the balsa wood. The blue electrical tape isn’t the prettiest part of the project, but it will eventually be covered up by the picture frame.So this is where I’m at now. I’d say I’m about 70% done. I still need to soulder one 330 OHM surface mount resistor to each blue, white, and green LED. I also need to soulder 2 rare earth magnets to each LED. Thats 200 magnets! Anyway, as soon as the magnets arrive (slow USPS delivery ftl) I’ll finish the project and post the final results.

Check back soon!

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*UPDATE*

Well unfortunately this version of the iLED project deteriorated into a giant mess and I eventually had to throw it away. After setting the circuit board aside for a couple weeks I came back to a corroded mess. Apparently any little bit of moisture that comes into contact with the copper strips will cause them to corrode and fall apart. Shitty.

I started over completely. Read more about iLED v.2.0 here.

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