The Much Larger Board Of Many Ping-Pong Balls 9


It’s finally done. When some people finish projects, they look back and say “well that went quickly”; this was not one of those projects. There was about 80 hrs of soldering, then there was the design, software, CAM, assembly, drilling, glueing, and going to CPC to buy cables. This was not a quickie. In case you have not been reading the past posts, then I shall brief you. I previously built an 8×8 ping-pong matrix with a colorduino. Then I ran out of creativity, so decided that my next project would be the same, but bigger. I quickly realised that the colorduino was a no-go method, so quickly made up some really crappy PCBs (call it the beta ┬á ­čśÇ ) with some 595s, BJTs and ethernet jacks. For reasons of shame they are not being Open Sourced, but never fear, the version 1.02 boards (which are smaller, and better in every way) WILL be released, and sold on, along with kits (slightly modified based on lessons learned, and you probably don’t want my link on the bottom of it, do you?), component sets .etc (modified┬áfor compatibility with solderlab code, as I can’t release my┬ámodified┬ácode die to copyright, and mine is still not perfect). Some technical details (here comes the maths) will also be on there, with some help for those designing there own matrix (how one works, blah blah blah).

PLEA – I am 15, and therefore have no money, and am in the UK, so no kickstarter. V2 is in the pipeline, but needs prototyping. I cannot afford this. I rely on funds from kit sales, so please make your way to AND BUY STUFF, thanks.

Back to normality, the software. As I was replying to comments on the youtube video for the original matrix, in the suggested videos I saw what must be the most amazing coincidence ever. A ping-pong LED matrix EXACTLY the same size as the one I was making (laser cutting at the time). I then proceeded to their website (now and downloaded their source. After a bit of compatibility modification I had their PC software up and running, and pushing frames perfectly. (I have my own in the pipeline, but not as good, yet). I also took some (quite a lot) of sections from their arduino and used them or learned from them for my own firmware. PLEASE, LOOK AT THEIR SITE, THEY ARE AWESOME. Yet more wonders of open source (or close to, there are some copyright issues for me selling the boards).

I could go all into the details, but I shall give all the tech specs on, where you are all heading to buy kits, AREN’T YOU. Suffice it to say that this is primarily for discos and similar, so lots of S2L, and very bright colours, just not a lot of them.



I could not have done this by myself, or afforded to do so, so here is a list of aiding parties

Stonyhurst Lighting Crew – After receiving the crash course in soldering, they soldered all the LEDs into grids, with only one board being messed up (you know who you are, Reece). They also put about ┬ú75 into the pot

Al Cringle (spelt wrong, I will change it) – Apparently using my idea of mending plates to join the panels was “not fast enough” for the school to use it, so I went down to Darwin, and we made a hook thingy (I say we, actually I did bugger all)

SCHOOL DT – Use of laser cutter, and huge discounts, and some freebies, and making all the GCSE┬ástudents┬ámiss their coursework deadlines with me hogging the laser cutter.

MIDGET – Our robotics captain, he helped with a lot of gluing, AS HE IS THE GOD OF HOT GLUE GUNS !!!!!!!! (yes, midget, that was sarcasm)

SOLDERLAB – From whom the code was nicked┬á


I shall now leave you with some pictures…


Leave a comment

Your email address will not be published. Required fields are marked *

* Copy This Password *

* Type Or Paste Password Here *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

9 thoughts on “The Much Larger Board Of Many Ping-Pong Balls

  • Donnerholz

    Love the whole thing – do you send the kit for 8 by 8 to Germany? What would be the total package price for that including postage?

    Have you thought about adding some further gear that reacts to movements or changes in light before a sensor ?

    • Da_Shroom66 Post author

      due to obvious postage problems, the kit does not include the laser cut boards, ping-pong balls, or stand components. I will happily ship the electronics bit to Germany.
      I can give you the ebay guy for ping-pong balls. These are china imports, so should be fine. For any bit of the actual construction, you can just send the .dxf files on to a laser cutting firm (google it, there will be several, especially in Germany). The stand is just 2″ by 2″ timber. I might do an instructables on it, but otherwise just e-mail me and I can walk you through the process of getting things laser cut locally.
      As for the sensor thing, my code isn’t ready yet, but you bet that when it is, that will be included ­čśÇ

  • Adam


    First off, love the project. I’m interested in building one of these for myself. Excuse the ignorance, but how exactly do the RGB LEDs work? Is the colour emitted decided by the voltage level of each pin?



    • Da_Shroom66 Post author

      Essentially. Any LED has something called a Forward Bias Voltage. after the voltage reaches it, the LED goes “On”. LEDs can be dimmed normally with a potentiometer (changes the resistance), but due to the voltage power curve, it gets messy (narrow range), and MCUs are really only good with digital. So LEDs are dimmed with something called Pulse Width Modulation. In this, an LED is turned on and off very quickly at different ratios to dim it. The RG and B pins each have this, and the ratios of the power to them creates the colour. The human eye cannot see the On and Off changes as they are so quick, so they are essentially averaged out.

      So essentially you are right, though the voltage is either an “on” or “off” voltage, and they change really quickly to average out to another voltage, which reflects how bright that colour is. These then merge to make a final colour out of red, green and blue.


    • Da_Shroom66 Post author

      Damn, I just got back from South Devon. Shipping is the same for the whole UK, depends on what you class as a “full kit”. Due to the size I can only supply the electronics stuff (no box big enough :-) )

      Kits are available from
      Though I have just run out of the PCBs and am having problems with the factory, so there is a RIDICULOUS lead time (months) for them, though this is mentioned on the site

      Thanks, George

  • Al Barrard

    Why didn’t I think of this before? This is brilliant. Recycling ping-pong balls gluing them with LED lights on a board is a great project idea to make use of excess materials in our storage rooms.

  • Matt

    Hi there, I have been trying to get some info on your kits but your site seems to always be down when. I look I live in the uk.
    Would it possible to forward me some details thanks.