Spice Up Your Dice With Bluetooth

There’s no shortage of projects that replace your regular board game dice with an electronic version of them, bringing digital features into the real world. [Jean] however goes the other way around and brings the real world into the digital one with his Bluetooth equipped electronic dice.

These dice are built around a Simblee module that houses the Bluetooth LE stack and antenna along with an ARM Cortex-M0 on a single chip. Adding an accelerometer for side detection and a bunch of LEDs to indicate the detected side, [Jean] put it all on a flex PCB wrapped around the battery, and into a 3D printed case that is just slightly bigger than your standard die.

While they’ll work as simple LED lighted replacement for your regular dice as-is, their biggest value is obviously the added Bluetooth functionality. In his project introduction video placed after the break, [Jean] shows a proof-of-concept game of Yahtzee displaying the thrown dice values on his mobile phone. Taking it further, he also demonstrates scenarios to map special purposes and custom behavior to selected dice and talks about his additional ideas for the future.

After seeing the inside of the die, it seems evident that getting a Bluetooth powered D20 will unfortunately remain a dream for another while — unless, of course, you take this giant one as inspiration for the dimensions.

19 thoughts on “Spice Up Your Dice With Bluetooth

    1. $35 for a single die, and Yahtzee needs 6. The Dice+ also look to be significantly larger. I didn’t read the product manual, so I don’t know if the application can support multiple dice or not. So yeah, it’s similar, but [Jean]’s are much cooler.

      And Simblee for the win. I worked on two products that had Simblee modules integrated into them. Not the cheapest solution to a problem, but it’s really easy to drop in to a project.

    1. Right now they are not perfectly fair, but I’m pretty sure I can solve that in the next revision. Since I have a pcb wrapped around the die, my general idea is to solder little weights here and there on the pcb to balance the whole thing. I also think I’ll want to pot the all the insides nice and solid so that nothing can shift around. In any case, it’ll be super interesting to figure all that out! :)

      1. Zero ohm resistors? That was my first thought. Another would be moving other components on the PCB around.

        As for your battery quandry: there have been micro-sized lithium ion batteries around for a while for wireless bluetooth headphones. I’ve had the damnedest time actually finding them from any distributors. The market for the style of headphones where everything is in the earbuds has pretty much exploded, so you’d think we’d be awash in them, but I don’t see them on Digikey. The ones in my wireless headphones are well under half an inch in diameter and bear more resemblance to a large electrolytic capacitor than a coin cell or lipoly pack.

          1. Sorry for the slow reply – I did some hunting around and found out that if you search for terms like “bluetooth headset battery” on the usual suspects, you can find some examples. They look very much like electrolytic caps, and thus a google image search is fairly handy. I’m not sure what their discharge rate is, but obviously someone’s making ones that are powerful enough to drive a two-channel audio amplifier and bluetooth transceiver :)

            There are “traditionally” shaped poly packs:


            Amazon of all places has some cylindrical ones, though these particular ones look too big: https://www.amazon.com/dp/B01NBAY854

            How’s 10x10mm? http://www.szaspower.com/bluetooth-device-battery/Cylindrical-Rechargeable-08100.html

            Even more examples:


  1. Very well executed!
    I had the same idea a while ago, then saw it kind-of realized in the dice+ kickstarter, but I thought having an opaque case would be a cool touch – so the dice just have blank faces until rolled, whereupon the LEDs light up and show through the case, like those wood LED clocks.

  2. Very cool!
    I haven’t seen many flex circuits in hobby projects. If I might ask, where did you get them made? And, did you find an assembly service to add the leadless parts, or bake them on yourself?

  3. You are crazy! …I like it very much… especially the communication part with any app and thru them to even tap into deep blue or watson (the name in today’s fashion…) in order to figure out the best game move. Game specific logic can communicate what to do next especially in a multi-dice setting.

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