Endless Fun With LED Dominoes


Toppling dominoes is great fun for about 30 seconds at a time, when you are not busy setting them up for another run. [Randy] thought it was about time they got an electronic makeover to allow for constant, immediate gratification. Armed with a few simple electronic components, he has created Le Dominoux.

These LED-based electronic dominoes are actually quite simple to build. Each basic Le Dominoux is constructed on a small square of protoboard and consists of either a photo cell or phototransistor, a 555 timer, and an LED, all powered by a coin cell battery. The 555 timer, which is configured as a one-shot, is triggered when the photosensitive component on the back side of the domino is exposed to a bright enough light. The LED on the front end of the domino is then illuminated one time. This process is the electronic equivalent of a single domino toppling over.

He has constructed several variants of the Le Dominoux to act as flashing triggers, for outputting sound, as well as for turning tight corners. These variants allow the dominoes to be configured in many different ways, creating self-sustaining light shows. If anyone is looking for a fun project to introduce kids to electronics, this would definitely be it. Stick around to see a video of Le Dominoux in action – we bet you can’t stop watching it.

This is of course [Randy’s] entry in the 555 Design Contest, which ends tonight at midnight EST.

[Thanks Jeri]


46 thoughts on “Endless Fun With LED Dominoes

  1. That’s cool. They work like some kind of synchronous digital buffer with independent clock sources. As noted in the video, interesting digital circuits can be built using them.

  2. I can’t help but be reminded of a synaps and in general, neural networks. . . with the addition of simple high / low pass and minimum / maximum weight nodes one could create a neural network building blocks. (Disclaimer: I know very little about real neural networks.)

    – RObot

  3. Um. Please get someone to start including these in happy meals. This is one of those toys that’s low cost and ostensibly simple but also have endless potential (eg legos, mecano, sand)

    I would totally buy like 30-50 of these suckers. Mass produced they should cost what, $0.25? I’d pay a couple bucks per…

    or kits. someone make a snap-together or foldup enclosure from cardboard or thin plastic we can get printed on thingverse.

  4. This is in my top 5 of best projects here on hackaday. It’s not hard to build, It’s low cost, and it has the best name on the end.
    I wonder what kind of things there are to make if U have a few hundred of these things

  5. @Aleks Clark

    “Each Dominoux costs about $1.75, not including labor.”

    so – you would actually have to buy a ton and ton in bulk to get the price down. each cell coin is more than $.25

  6. @Alan

    well yea. by mass-produced I mean a solder blob + some LEDs + smaller coin cell. like the kind you find in a lightup happy meal toy. $0.25 might be too optimistic, but $1 would be fairly easy to achieve. You could probably even get them down to $1 just by buying everything in bulk for kits.

    as soon as I’m done moving, I’m totally making a bunch of these and whipping up a papercraft enclosure that looks like a domino.

  7. I’m already calling China, they’ll be in stores by April! One thing I thought of, if you tuned a bunch of the sound producing LDs (well what would you shorten LeDominoux to?) you could play songs with them. This thing could have thousands of uses and its so simple, I love it!

  8. Holy shit when I saw the picture I was like yawn but holy shit it looks like fun.

    As someone said put this shit into happy meals and accidentally all my money.

    Hell if you had random special ones like the buzzer, timed blinker or even logic gates holy shit.

  9. thanks to this i just ordered 50 555 timers from ebay…. i will be building a version of these with the addition of a magnet to the bottom and a large metal panel for my wall, i want to make a kind of digital, modifiable art.

  10. Hopefully the commercialized version (there can’t not be one, it’s too cool!) will use EDLCs (supercapacitors) instead of disposable lithium coin cells.

    I’d buy a hundred with a charger, and maybe some logic-gate modules, to recreate a physical version of Rocky’s Boots. :)

  11. This is awesome, on many levels.

    Firstly the simplicity of the build – even I could probably make a few of these gizmos!

    Secondly and most impressively – you get a really brilliant demonstration of the principles of “emergence”. A simple ordered system (light on a delay triggered by another light) being able to develop into chaotic systems simply by arranging them in a different configuration.

    I’d totally pay one or two dollars each for these little beauties, if they were properly (robustly) manufactured.

    I absolutely love this idea, I’m going to make a few of these myself!

    This is now my new all time hackaday fave project!

    This made my day.

  12. So I sketched this up in Eagle with 1206 caps and resistors and a 12mm coin cell holder and I can get 330 boards for $200 (the individual boards are 0.8″x1.11″). After including the parts, which in quantity run less than a dollar per board, we get a price of about $1.50 per board, minus assembly (I’m purposefully overestimating the cost of parts).

    So one could probably sell baggies with all of the parts in them for about $2.50 per board and turn a little profit (no batteries)!

  13. Grand like this style! simple – artistic and its lights! freakin great! and nice video too.. so where can i get really cheap timers?

    and im in Mas right now any place where i could crash in and get some neat electronic stuff to scavenge?

  14. That’s freakin’ awesome!

    I wonder, could encode some PWM (or other means) into the lights to send information to each of the modules?

    Doing so would allow you to send timing data to change crawl speeds or perhaps even give each module a different personality.

  15. @Aleks Clark: Sure, you probably could get it much smaller, but if you were going to sell them as bags of parts, you’re going to be telling people to solder them.

    I normally assume that 1206 is the scariest I’m allowed to make a board if I don’t know who will soldering it.

  16. I hope this does NOT get mass-produced.

    These toys undoubtedly end up in the waste bin some day soon, likely sooner than you would think.

    It’s a nice idea and all, but one day either the batteries are dead or you have shown it to all friends you know and it looses its appeal.

    Honestly. You shouldn’t produce cheap disposable electronic toys that contain rare and toxic materials like in the batteries or electronic components. Even if lead-free, it’s still a waste of natural resources. This is completely non-renewable!


  17. @Tom

    I’m much more likely to change the battery in this than I would be in some random light-up Avatar doll from mc’ds. Saying these would end up in a garbage bin is silly. See above about emergent behavior. It’s not just a cool blinky thing that you mess with once, it’s a toy with which you can create entire systems, like lego, mecano, or any other sandbox/building block style of toy. The fact that the individual components can be trivial (1x clear lego flats anyone?) doesn’t make the system as a whole trivial.

    A simple solid-state device like this will last a LONG time. The fact that production would be cheap does not mean it’s junk. Better a toy that teaches than some piece of REAL junk that can only do one thing, and uses the same resources.

    If you REALLY care about it being renewable, how about you quit the nay-saying and sketch up a version that uses supercaps and is inductively charged?


    true, a diy kit would have to have some larger bits. Although, the low part count would make it a really good “learn to solder SMD” project, since fudging one of 20 LDs is less traumatic than frying the one ATMega in your $30 SMD clonduino. SMD 555’s are 14 cents @ 100 pcs! The battery is the big issue…

  18. @Aleks Clark: Yeah, I was thinking that maybe a supercap would be a better choice? Certainly it would raise the price… or would it? It chops out the battery holder and adds an overall cost of a charger circuit (also some mild additional circuit complexity to accommodate hooking them all up in parallel to the charger).

    And yeah on the front of a “learn to solder SMD” boards. These are simple (8-9 smd components) and I also wanted them to be easy to build, so the components are big and easy to solder.

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