Static, flashing, or animated colored lights have long held a fascination for me -- anything from a single LED blinking on and off to a full blown RGB laser show. Over the years, I've built various light boxes and have owned (for a short time) an RGB laser. My most recent project was installing Adafruit Neo-pixels in my hallway skirting board along with an Arduino Uno embedded in the hallway wall for controlling them (see also Hallway Lighting Project: Controller & PSU).
An 8x8x8 3D LED cube requires a lot of LEDs.
Following the implementation of the hallway lighting project, I started looking for something else to build. I still have just over 25 meters of Adafruit's NeoPixel Strips sitting around not currently being used. One possibility would be to construct a spectrum analyzer similar to Max Maxfield's BADASS Display. However, I'd previously created a 16x12 spectrum analyzer panel using WS2801 Pixels from Adafruit, so I wasn't particularly keen to build a new panel using NeoPixels.
One thing I had been contemplating was the building of a 3D LED cube. Now, I had seen some basic 3D LED cubes on the Internet, but nothing had really caught my eye sufficient to inspire me to leap into action. Then I saw an article by Max about his Screw-Block Proto-Shied for the Arduino. I immediately bounced over to take a look at the associated Kickstarter project, only to discover that I'd missed the deadline to back it. I contacted Max to see if there was a way to obtain the shields and he replied swiftly stating that as soon as he and his co-conspirator Duane Benson had satisfied the Kickstarter pledges, they would get back in touch with me.
Max also sent the links to some other blogs he'd written on EE Times. One of these articles was about 3D LED Cubes, and it was this blog that led me to look at these devices once again. Initially, I was tempted to buy a cube kit or one that was already built. I did find what looked to be a professionally made 16x16x16 cube, but it came with a price tag of nearly £6,000, and I certainly wasn't going to fork out that kind of money.
After watching the very detailed video blogs by Kevin Darrah, I decided to have a go at building my very own 8x8x8 cube from the ground up.
One of the first tasks when building one of these cubes is to acquire the LEDs themselves. I looked on eBay for some reasonably-priced 5mm diffused common anode tri-color (RGB) LEDs, and I found a seller in Hong Kong offering 1,000 LEDs for just under £35.
This shows my test setup, which is discussed in more detail in Page 2 of this column.
Another key component is the wire used to define the structure and link the LEDs. Kevin Darrah had used sheathed copper wire and stripped it back, but I'm not sure why he did that when tinned copper wire is readily available. I decided that 20SWG wire should be slightly sturdier than the 22SWG that others building their own cubes had used, so I ordered a 500g reel of 20SWG tinned copper wire.
I'm happy to report that both the LEDs and the wire arrived in a timely manner. The LEDs arrived in an antistatic bag. It was when I tipped out the bag into an empty container that I thought: "Wow, that's a lot of LEDs!" It was at this point that I started to realize just how big a task it would be to construct a cube containing 512 LEDs and more than 2,000 solder joints (not counting the control circuitry).
To Page 2 >