Intro: The Board of Many Ping-Pong Balls
Le wilde project
Firstly I would like to apologise for any lack of clarity .etc; I am 15, and therefore have no skill .etc
This is an LED matrix
It has 64 RGB LEDs mounted in ping-pong balls, on a laser cut (8x8 grid) board
Drill or Dremel
Arduino Programmer (arduino, FTDI friend or cable .etc)
64 common anode RGB leds
64 ping pong balls
Laser cut board
You can buy all the parts (save consumables like glue and solder) at www.dashroom66.com.
Assuming that you don't have a laser cutter, you can either get a per-done one from me, or get one done by ponoko or similar.
I know the kits are expensive, but the price will drop quite heavily as soon as more orders come in.
IT IS A LEARNING EXPERIENCE
if you build this it is hard not to get something from it, be it practical skill, programming knowledge, plasma algorithms .etc
Just make sure you have common sense and aren't stupid. I will teach you how to solder very quickly, but there are better guides on YouTube, if you just want.
Step 1: Why ??
1. It's green; it uses only about 1 watt, but gives off quite a bit of light
2. It's size; I normally go with bigger is better, (and a bigger one is on it's way), but it is small enough to be mounted in really nice, convenient places. It is also big enough to be noticed
3. It is colourful; it has 16 million colours to be precise, more than enough to brighten anybody's day
Step 2: Die Software
Most people build stuff, then put in the arduino, then program it. I don't subscribe to this. I think that it is much easier and more efficient if you program and build the electronics in parallel. Every time you have an individual part of your circuit working, you then program that bit to work. It saves so much time, and makes you feel like you are getting somewhere. (also it helps if you build outwards from the MCU, ie regulators, then transducers, then outputs). But in this case it is easier if you program it first. For a start just use the demo code. I first used a tweaked version of the domo code by lincomatic, who also made a very good library. You can find it here a
The next step is to wire it up to your computer, the wiring is as follows
You can also use an FTDI friend or similar. The next step is to open up the arduino environment, available at arduino.cc, import the library, restart it, then open the code. Select the board that you use for the serial (ie the arduino, not the colorduino), and upload the sketch.
If you have trouble with the arduino enviroment (it happens to everybody), then you can get help at the arduino website listed above.
Step 3: Board + Ping-Pong Balls =
This is the fairly self explanatory bit, but there are a few nice build tips here, so it is quicker and looks even better. The picture of the board is the one generated from the CAD program, ProDesktop, that I used to design it. After you have had it cut / cut it / bought one from me, this is what will be staring you in the face.
The next step is, surprise surprise, glueing on the balls. When I built this one, I did the balls in lines of 4, by getting the board upside down, then putting the balls under it, wobbling the board around until they aligned with the holes, then glueing them. This was inefficient and ineffective. You then had to wait for ages as the hot glue dried, before you could lift it again to get the next ones under. When building my new, bigger one (not yet finished), I had a new method, which is much quicker. Here goes...
For this way you need to find any flat object the size of the board, be it a bit of Ikea flat-pack furniture that to this day you cannot find where it was meant to go (this was me), a bit of wood, or some strong cardboard, or whatever.
1. place the board RIGHT SIDE UP, so that you can see the side that you want to be the front (probably the side without burn marks, or if you want to stain it / cover it in stickers.etc, then that side.
2. Place all 64 ping pong balls (note, make sure that they are all white with no markings, unless you want them for style) on the board, in the holes. They should sit neatly on top. If you are going to stylise it, then this is how it will look when glued.
3. Place whatever flat thing you have selected on top of it so that it covers the whole board. Them, holding it firmly, flip it. The rear side of the board should be facing you, on top, with the flat thing on the bottom, with the balls sandwiched in between. Looking at the board from above you should see the balls through the holes. If you need to, adjust some so that they fit neatly.
4. Glue (with the hot glue gun) round the edges of the holes, touching the balls. The seal should go all the way round. It will secure the balls to the board, without the glue being visible from the front. On some balls, you might see bubbles rising through the glue, and possibly hear a strange deflation sound. This is because the hot glue has melted a bit of the ball, and as it is under pressure inside it, some of the gasses escape, causing the bubbling. This is not a problem, but take it as a hint to more on to glue the rest of the circumference, or if finished, the next ball.
IF YOU DON'T KNOW HOW TO USE A HOT GLUE GUN - READ THIS
Ok, solid glue tubes go in, melted glue comes out, melted glue solidifies.
Just put the glue stick into the back of it, then plug it in (turn it on if it has a switch, many don't).
Wait a bit, then put the tip on the bit that need glueing. Pull the trigger, hot glue comes out.
You can slowly pull the trigger, and drag it, to glue a large area, OR ROUND THE EDGE OF A HOLE ON AN LED MATRIX
Step 4: Soldering
This is the stupidly long, boring, suicidal bit. BUT, because the board is already programmed, it is a bit easier.
From the photo you can get a good idea of what must be done.
First place the LEDs into the balls. Drill a hole in them first :-) Make sure that they are all orientated the same way. Bend the Common Anode downwards (usually the longest pin). Then bend the outermost pin at each side to their respective sides. There will be one pin left pointing up. Point the pin next to it on the outside slightly towards the top of the board, so it is pointing North east/west, if North is the top of the board.
First solder the rows. This is the only bit done on the photo. Just join them all together with wire (can be bare, I just forgot when I did this one, but if you do, you need to tape it.
At some point I will do a "how to solder", but for now just use this guy's very good tutorial
You don't need to bother twisting it, just bend them together. The joints don't need to be perfect, just as long as they stick.
Then put the wire into it's respective hole in the colorduino and move on to the next.
Next give the colorduino some power, from any power supply you want (providing it is 5V), such as an arduino, ATX supply, wall wart, bench supply .etc
You can then start doing the columns, they work in the same way, but make sure you put the wire into the right colour hole. You should start to see the LEDs light up. This is both motivational (which believe me is needed) and let's you test as you go along. This is why we programmed it a the start.
The last colour you should do is the pin sticking upwards, you should bend it to the near side, but slightly down as well.
The second photo is after I did a whole column.
Step 5: C'est Fini
You should have now gone and done all the columns.It's now up to you what to do with it, I hung mine on a wall. You can now start to mess around with software, which can be fun after you get to grips with it, but this bit is up to you.
Kits can be bought from
Any files will either be there as well, or on my blog
Thanks for reading :-D
And don't forget to vote for me in the laser cutter contest :-D