Electronic Dice

A set of smart dice, the same size as traditional ones, full of LEDs and Bluetooth-enabled.

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A set of 'electronically augmented' dice. Completely customizable, they can be used as a drop-in replacement for regular dice, and are configured via bluetooth. They can also be used to keep track of all your rolls, direct your phone to play sound effects, or even used to play DnD online.

Here is a video presentation of the project:

The dice are based around a Simblee module (that conveniently combines an nRF51 chip with a chip antenna). The LEDs are currently charlieplexed using an I2C GPIO controller (mostly because the Simblee module cannot source or sink enough current). There is, of course, an accelerometer to detect orientation, and a small EEPROM to store non-volatile data.

Note: the next version of these dice (see Project Logs) will replace the LEDs and charliplexing with a set of daisy-chained APA102 RGB LEDs, making the dice at least 256% more awesome!

There is even a small magnetic switch such that I can eventually build a carrying case with small embedded magnets that will make sure the dice remain off during transport.

All the electronics are soldered onto a flexible pcb and then wrapped around the battery in a cube shape, so that the LEDs face outward. All the other components had to be on the other side of the board.

The case is 3D printed (Shapeways) and currently measures 17mm on its side (a standard die is 16mm).

It was very challenging, in a fun way, to design the pcb and the case at the same time. Because of the small space, I really had to constantly think how layout would affect the way everything fit together in space, and vice versa.

Dice V3RevC PCB Bot.pdf

Next revision of the Dice. Bottom of Flexible PCB

Adobe Portable Document Format - 73.77 kB - 03/01/2018 at 17:17


Dice V3RevC Schematic.pdf

Next revision of the Dice. Schematics

Adobe Portable Document Format - 270.04 kB - 03/01/2018 at 17:17


Dice V3RevC PCB Top.pdf

Next revision of the Dice. Top of Flexible PCB

Adobe Portable Document Format - 41.62 kB - 03/01/2018 at 17:17



Top Layer of Flexible PCB

Adobe Portable Document Format - 61.49 kB - 11/29/2017 at 01:32



Bottom Layer of Flexible PCB

Adobe Portable Document Format - 46.76 kB - 11/29/2017 at 01:32


View all 6 files

  • 1 × Simblee Microcontroller + Bluetooth radio + chip antenna
  • 1 × PCA9538A Microprocessors, Microcontrollers, DSPs / IO Controllers
  • 1 × AH1884 Switches and Relays / Switches
  • 1 × 24C04A Memory ICs / EEPROMs

  • Prototype 4

    Jean Simonet08/25/2019 at 00:19 0 comments

    Hello again friends! It's finally time for an update on the Electronic dice. I just returned from showing the latest version at Gen Con, and it was fantastic! So, what's new?

    Well, first and foremost, the new prototype is of a D20! Still regular size, still full of LEDs, still inductively charged, and still awesome. In fact, I think the D20 is by far the most fun light up die. There are, however, several other differences with previous prototypes.

    Read more »

  • Prototype 3

    Jean Simonet07/02/2018 at 17:03 6 comments

    This is the next revision of the Electronic Dice. I've spent a lot of time putting it together, and it is really coming along!

    Looks pretty nice, doesn't it?

    So first things first, this version is exactly 16mm, the same size as a regular dice. And as you can see here next to the previous prototype, it is also more rounded. It's amazing how much difference 1mm can make, both in how the dice feels in your hand, and how much harder it is to put together!

    Read more »

  • RGB Dice prototype

    Jean Simonet02/04/2018 at 22:47 1 comment

    Hey all,

    I finally finished the second board for the Dice, the full RGB one this time! It's pretty awesome already! I don't have a flexible PCB version yet, but this here is a prototype board.

    Those APA102 2x2mm look really awesome!

    Read more »

  • Tiny Lipo Batteries

    Jean Simonet12/29/2017 at 19:52 0 comments

    Following a suggestion from a commenter on youtube, I was able to find a lipo battery small enough to fit in the dice! I received samples early this week, very exciting!

    Lipo next to current battery (non-rechargeable lithium)

    I got so excited to start seeing if I could make the next version only 16mm wide that I started working on the schematics and now 3D CAD. That's just as well, since now I can get prototype boards made while I continue to work on the firmware.

    Read more »

  • Twitch streaming

    Jean Simonet12/20/2017 at 22:07 0 comments

    Going to do some streaming in just a bit, stop on by if you like!

  • A shorter presentation video!

    Jean Simonet12/01/2017 at 00:25 0 comments

    I put together a shorter video, less technical and more like a sizzle-reel.

    Hopefully I can get back to work soon! Taking pictures and editing stuff together, let alone re-recording stuff a gazillion times, ends up sucking up soooo much time...

    Anyhow, hope you all like it,


View all 6 project logs

Enjoy this project?



crjeder wrote 01/12/2018 at 14:33 point

They look amazing!

Are those dice stil fair? Or do the most of the time show e. g. the face on the top of the battery?

  Are you sure? yes | no

Jean Simonet wrote 02/04/2018 at 22:59 point

Sorry for not replying sooner. The current version is pretty poorly balanced, and I can tell you that with perfect certainty, as I can record every single throw. :) The 4 face comes up about 15% more than any other...

I have several plans of attack to make the next version fair. For starter, I am getting rid of the screws, and making sure the battery is centered. But I also will be able to cut little strips of sticky lead tape (used for golf clubs I think) and stick them on the board or case where they need to go. It'll be hard to know where that is until I have the first *new* die assembled, but I think it'll work!

  Are you sure? yes | no

Juan Rial wrote 09/12/2019 at 09:44 point

I wonder how difficult it would be to build a miniature version of those machines they use at tyre shops to balance your wheels? That would drastically cut down on the time required to balance them.

How do they balance commercial dice anyway? I can hardly believe those are balanced by tossing them a couple thousand times and recording the results each time. ;)

  Are you sure? yes | no

Bastiaan wrote 12/06/2017 at 18:45 point

This is a really awesome project and I enjoyed your video. You talked about looking for rechargeable batteries that fit the requirements, have you looked at super capacitors? There should be ones with a decent capacity at the size of the battery you are using and will keep components to charge it to a minimum. Maybe it won't fit the energy requirements you have, especially with Bluetooth and RGB LEDs but they store some decent amount of energy. Also, wireless charging would be really great, but that's even more parts in there ...

  Are you sure? yes | no

Jean Simonet wrote 02/04/2018 at 23:00 point

I was eventually able to source some properly sized LiPo batteries (See project log). Thanks for the suggestion though!

  Are you sure? yes | no

Bastiaan wrote 02/04/2018 at 23:20 point

Just read your new log on the RGB version, I'm really impressed. The original ones already cramped in a lot of stuff, and this just takes that a step further. Great to see them coming along! :) I'm going to look at those APA102 LEDs, they seem interesting. 

  Are you sure? yes | no

Guy Carver wrote 11/29/2017 at 17:38 point

Pretty damn cool Jean.

  Are you sure? yes | no

Jean Simonet wrote 11/30/2017 at 05:38 point

Ah! Thanks boss! ;)

  Are you sure? yes | no

Chris wrote 11/29/2017 at 04:25 point

You could use a coin battery with an external recharger for the time unless you actually want it to be completely self-contained.

Great work! ヽ(´▽`)/

 I love the integration and since I'm a dice lover I really want some of them!

  Are you sure? yes | no

Jean Simonet wrote 11/30/2017 at 05:41 point

Thanks! I'd love to get to the point where I can offer you some ;)

  Are you sure? yes | no

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