VolumELeD: Work In Progress
In case it wasn't obvious from the rest of my website, I have a thing for LED lights. Not sure why, some people watch TV, some people play computer games.. I play with LED lights..
About a year ago I started thinking about building a properly epic LED display, something big enough to stand inside! I know there are bigger displays out there, but as far as hand soldered, on a hobbiest budget, volumetric LED displays go, I think this one will be the biggest...
Each voxel is made of a custom PCB, (painfully hand soldered for that personal touch) fitted with a 10mm RGB LED and the trusty WS2801 LED driver chip. The key feature of my design here was to build a low cost prototype that was very easly upgraded or expanded. The advantage of using a chip like the WS2801 was that in the future I can replace these single LED voxels with high brightness multiple LED voxels for outdoor use, without any changes to the actual architecture.
Custom WS2801 PCB
I Wasn't Kidding About Painfull
More Column Drivers
I wanted each of the panels of my display to be capable of acting as individual, stand alone displays in their own right. This will give me the flexibility to arrange them in any number of different configurations..
The only problem was that this made getting data to the panels a bit of a challange. I was stumped for a while, until one of the electrical engineers at work recommended that I ditch wires all together and go wireless.
Daisy Chained Column Drivers
Yep, That's the Ceiling
Each of the panels is driven by an Atmega328 on a custom pcb that grabs the frame data from the Nordic RF chip and uploads it to the panel. The RF is a nice touch, all I need to plug into the panel is power and I can control the display from anywhere. Using this setup I can update the 10x10x10 display at 60Hz comfortably.
I can easily expand the display with this setup to a 25x25 LED panel before I run out of ram on the Atmega328 panel drivers.. Of course at this size the RF datarate would really limit the framerate, so I have designed in the capability to hardwire the panel drivers and update them over high speed SPI (just in case).
Prototype Panel Driver PCB
Shiny New Panel Driver PCB
One Down, Nine to Go
Only 10% complete and I am already running out of space in my tiny flat, so far my wife is surprisingly ok with me taking over the dining room again.