The Open, Hackable Electronic Conference Badge

Electronic conference badges have been around for at least a decade now, and they all have the same faults. They’re really only meant to be used for a few days, conference organizers and attendees expect the badge to be cheap, and because of the nature of a conference badge, the code just works, and documentation is sparse.  Surely there’s a better way.

Enter the Hackable Electronic Badge. Ever since Parallax started building electronic conference badges for DEF CON, they’ve gotten a lot of requests to build badges for other conventions. Producing tens of thousands of badges makes Parallax the go-to people for your conference badge needs, but the requests for badges are always constrained by schedules that are too short, price expectations that are too low, and volumes that are unknown.

There’s a market out there for electronic conference badges, and this is Parallax’s solution to a recurring problem. They’re building a badge for all conferences, and a platform that can be (relatively) easily modified while still retaining all its core functionality.

OHSBadge Labelled

Of course, to build a multi-conference, multi-function badge, Parallax would first need customers. They found that in the Northwestern University Center for Connected Learning. [Dr. Corey Brady] and [Dr. Uri Wilensky] are studying how people interact with each other and how diseases spread. They needed an electronic badge, and the needs of researchers aligned with Parallax’s desire to design an open electronic badge.

Out of this collaboration came the Hackable Electronic Badge. On board this badge is, of course, a Parallax Propeller. There’s a white OLED display, accelerometer, resistive touch pads, and of course prototyping pads, should anyone want to build a quadcopter out of a conference badge. Power is provided by custom charging circuitry and a AA-sized Lithium Ion battery, giving the badge 12 to 18 hours of run time.

Terminal window of the badge's Contact Manager
Terminal window of the badge’s Contact Manager

Hardware is just one aspect of a successful badge, and for most single-event badges the software is usually the weak point. Now that the badgemeisters have a stable hardware platform, it’s time to develop a few useful applications. The first such application is something called a Contact Manager. This application uses the IR communication LEDs and 32k of the Propeller’s EEPROM to store up to 500 contacts of the people you meet at your next con. Swapping contacts is as simple as uploading your contact information in one of the example programs, touching the OSHW logo, and pointing your badge at another badge. The contacts you receive are then saved in the EEPROM, and can be dumped by connecting the badge to any terminal emulator. You can check out [Ken Gracey]’s video demo of the Contact Manager application below.

The Hackable Electronic Badge will make its debut at its first conference this weekend at the Open Hardware Summit in Philadelphia. It’s not a requirement for the conference – everyone gets a paper badge and a lanyard, the electronic badge will be $40 extra – but it is the first time the badge will be used at a proper con.

I'm calling it. First badge hack.
Calling it. First badge hack.

Because this badge will serve as the prototype for future con badges, most likely including next year’s DEF CON edit: nope, this will be the first time badge hackers will get their hands on the hardware months before the event. That means badge hackers will be able to develop strange applications well before the event, and be able to reuse that code many conventions later. It may sound like cheating, but that’s the entire point of a badge platform as opposed to a single-use badge; reusing code and layouts brings the cost down and the number of applications up. It also enables a good bit of badge hacking before the event; I’ve already put the Hackaday logo on the badge.

As would be fitting with a badge for the Open Hardware Summit, the entire thing is open source, from the Propeller microcontroller to the source code and DipTrace files. All of the files will be available here in due time.

For a single conference bade, this is a great achievement. This year the Open Hardware Summit will get one of the most advanced and capable hardware badges ever made. It doesn’t end there, though, and building a platform for other conference badges really makes this project shine.

25 thoughts on “The Open, Hackable Electronic Conference Badge

    1. Well this doesn’t have a radio, and it’s not a node in a mesh network IRC channel thing. That’s the killer app for the HaDge. Work on the HaDge will continue.

      However, there are a three or four cores left on the propeller with the current feature set, from what I’ve seen of the semi-official code. There are also I2C pins broken out, and *more* than enough flash for a mesh network stack. It might be possible to implement the HaDge on this badge. We’re already making a version just for testing/prototyping, and it wouldn’t be *that* hard to put that in a Parallax badge-compatible format.

      I’ll talk to the parallax guys next weekend.

      1. “….There are also I2C pins broken out…..” just a note, ANY 2 available pins on the Propeller can be used for I2C. Pins are not hardware bound, so any can be used for serial, I2C, PWM, etc…

    2. Nope! Work on the HaDge should certainly continue! One thing I can say for certain is that these projects evolve with the availability of new parts, and the hardware needs to use them. The HaDge has some RF networking capability so that’s very unique. Feel free to pull any of the Parallax resources we’re posting for the HaDge, too.

  1. A reusable Prototyping area would be more useful (IMHO) for badges that will be reused.
    Or a daughter board connector.
    Why all blue LEDs? Why not the multicolor ones or just other colors, (e.g. red, yellow, green for status)

    1. I guess pins could be inserted into the two rows of proto holes (marked P0-P11) and a daughter board pressed onto them.
      (sarcasm mode ON) But we’d a new arbitrarty name for these supplemental boards, as they aren’t shields, hats, capes or whatever)

      1. Before those names were popular we used names like daughterboards, application modules, add-on boards, expansion board for x/y or whatever. I’d personally like to have one with a microphone input so I could make a musical tuner. If somebody would make that I’d be really happy (and yeah, I understand I’m the only person who wants it!).


      every pcb should have an array of .1 grid proto holes. and mounting holes, too; its amazing how often pcb’s are made that have no way to mount them to some base or box. the open bench logic sniffer comes to mind; a board that has NO mounting holes. what WERE they thinking??

  2. $40? For a *badge*? Oh, c’mon! This is the very antithesis of a hacker’s badge.

    For a hacker badge, why not instead pick some existing gadget that’s mass produced and widely available at very low cost? Say, a $2 calculator, or $5 LCD display? Hack its onboard micro to make *that* your badge? Or *build* something, for heaven’s sake! How about the display out of a cheap digital clock that you hijack to do your bidding with a $0.50 PIC?

    1. SILENCE! THOU SHALT INTERFERE WITH MODERN COMMERCIAL “HACKING”! Srsly though, what’s the point just throw around $ to so one can feel like they are part of something without actually needing to do anything? I’d be more impressed with a badge on perf board.

      1. That’s how I built mine. It’s a 2″ x 2.5″ piece of perf board, with a 7-digit 7-segment LED display, an EPROM, a 74LS145 decoder/driver, and a 4040 counter. The counter addresses the EPROM and decoder. The EPROM is programmed with eight 7-character messages. It scans the LEDs to display the messages sequentially, about one every half-second. Cheap, simple as dirt, and obviously home-made. :-)

        If anyone’s interested, email me at and I can send you the circuit and pictures.

    2. What about those $10 android phones mentioned earlier. The only bad thing is battery life, but with custom code, that could probably be solved. Also would have good communication possibilities.

      1. Maybe like a “bluebadge” software badge type thing that is simply a non security bluetooth phone that when paired with a software serial terminal dumps contact details. Maybe make a “DOT11 ” badge which is simply an unsecured access point that redirects all browser requests to an html with contact info.

    3. If you have to buy purposely built badges, you kind of missed the whole point of hacking. i.e. using something for what not it is intended for.

      It is like in game purchases so that you don’t have to level up to “win” so that you can impress your “friends”.

    4. Or you can make one yourself a clone or a compatible one. Lately i’ve been using as “badge” just a ESP8266 disguised as AP, with SSID as my e-mail address and password set as my name. When logged it would serve a simple page with links. 10€ tops included battery for a day.

  3. Hey Brian, I think I might show up for this. And who knows, if I finish my move soon, I might also be finally able to get to work on my Flight Data Recorder. ;) It’s a pity they probably won’t have a ton of tools available, or else I’d consider dragging that stupid thing all the way to Philly with me. :D

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