LED Array Projector

Discussion Projects
1

I thought this might be of interest… I made an LED array projector from a Unicorn HAT HD and an Ektanar 102 mm lens from a Kodak carousel slide projector.

To build it, I attached two pieces of lumber at a right angle and mounted a Raspberry Pi Model B+ to that with set screws. I used 2-inch diameter pipe clamps to secure the Ektanar lens to another piece of wood. Then I combined the two sub-assemblies using c-clamps, which can be loosened to focus as needed.

I attached a segment of dried bamboo for rain cover, and put rubber stoppers into the exposed ports of the Raspberry Pi.

I mounted the completed projector to a Sony VCT-R100 Lightweight Compact Tripod with a 1/4"-20 x W3/8" x L7/8" coarse thread coupling nut.

led_array
led_array4032×3024 3.08 MB

Finally, I threw a couple of bolts of white fabric over an old lemonade stand to serve as a screen.

I adapted show_png.py in the Unicorn HAT HD examples to display a short holiday animation.

Like a movie projection, the image isn’t particularly bright and needs to be isolated from ambient light. But it’s striking!

2

Now that’s very cool! I suppose those LEDs would never get anywhere near as bright as a projector bulb, but they’re a heck of a lot cheaper!

3

Ditto to what @Shoe said. =) I have a couple of Unicorn HD’s in use here.
If you leave out the diffuser they should be pretty bright.
It’s nice to see what happens when somebody thinks outside the box. ;)

4

Thanks, everybody.

Yes, I expect projector bulbs are extremely expensive to power.

I was glad that the diffuser wasn’t epoxied to the array, etc.

5

I’ve added the black ninja diffuser to a couple of my builds. LED arrays like the Unicorn HD, Sense Hats, LED shim etc. It makes text look a lot better and easier to read etc.
Always nice to have the option to use it or not use it etc though.