#belgium slack discussion regarding electronic display name badges

  • CoderDojo Foundation

    This discussion originated on the CoderDojo Global Slack instance on the #belgium channel. It is being shared here to encourage further discussion and to enable those not on Slack to read it.

    Jan Tiri [3:58 PM]
    CoderDojo will participate at the fri3d.be camp with a workshop. This camp has its own hack able badge, based on esp32 and can be coded from an arduino IDE (check: http://fri3d.be/badge). I know the guy who designed it and he wants to design one for CoderDojo as well.

    Potential use case: link the badges with Eventbrite so you can program them upfront. Participants and coaches can then register themselves by picking them up and push a button. When the dojo is over, they simply return them. During the Dojo, the badges can scroll the participants name, traject and other dynamic information. Eventually, we can add IR to enable laser shooting etc…

    Quick poll:

    1. would you use these badges at your dojo & how many would you require?
    2. do you have other use cases & ideas?
    3. would you like to help designing these badges? (graphical layout of badge, link to Eventbrite, programming, …)

    If there is enough interest, we can start working out the financials.

    Bart Huylebroeck BE [4:14 PM]
    Hi @Jan Tiri! We’re thinking about creating exactly such a name badge for DojoConBe 2018. I’ve ordered a prototype wemos esp32 + oled just today :wink: Features I’m looking for:
    large screen area vs pcb (preferably: screen on one side of the pcb and chips underneath the screen or on the other side of the pcb).
    power from mini-usb connector or from lipo connector,
    Lipo charging electronics on board,
    ideally WIFI enabled

    WimVG [10 days ago]
    We opted for single sided assembly for the Fri3d badge in order to get a lower production price. (which is sponsored by Dekimo, the company I work for) Only the battery (replaceable 18650) is soldered on the back, since this is a though hole part, it’s being soldered manually.

    Jan Tiri [4:18 PM]
    ESP32 is already wifi enabled, so that should be ok. And looking at the fri3d design, I would also prefer to have an additional matrix, IR receive and mass charge functionality (wireless charging?)

    Bart Huylebroeck BE [4:38 PM]
    any idea of the cost per piece? Does it include battery? Or budget would be around 10 euro pp

    Jo De Pelsmaeker [10:41 AM]
    Hey @Jan Tiri! Great idea !!!
    In Aalst we are using multicolor lanyards because some coaches aren’t to fond of the white T-shirt. It’s a wasking-ironning-color-size issue, not that important.
    So we are using a lanyard to mark that a person is a coach (but most of them still wear the T-shirt). We never had any good idea what to hook onto the lanyard so … this is it. Plus we have a coach who got the word of your idea and he is already eager to start with is. He already wears a Microbit each Dojo. So 20 for our coaches and cooks to start with, I guess. Coach communication is the first and straightforward thing I am thinking of. But our techstuffcoaches will have many more, I am sure. Looking forward to it. Jo.

    Jan Tiri [11:56 AM]
    @Jo De Pelsmaeker My main use case was about the participants, as to avoid printing stickers and checking them in manually. We could even link it to an rfid membership card so the badge is programmed on the fly… but yes, the coaches should wear it as well

    Bart Huylebroeck BE [12:38 PM]
    using rfid to program a name in the badge quickly and easily sounds great!

    Coderdojo Izegem [1:09 PM]

    Jan Tiri [4:24 PM]
    10 euro will be challenging. We could discuss if we could mix the cafetaria budget per dojo with a special project one

    WimVG [10 days ago]
    ESP 32 = €3
    USB interface = €2
    Battery (Chinese) = €1.5
    PCB = €1.5 (size dependent)
    Battery holder = €0.40
    Battery charger + Protection = €0.25
    If Servo control is needed, the 5V 2A boost converter would set you back €1.5
    Accelerometer = €0.5
    Single Shift register for LED matrix = €0.1
    Single color SMD LEDs = €0.003 / piece in high volume
    Piezo buzzer = €0.5

    Jan Tiri [10 days ago]
    plus pcb assembly

    WimVG [10 days ago]
    plus €0.4 if you want a better way of controlling the dot matrix display (HT16K33)
    Shift registers are fun, but a PITA when it comes to timings (Fri3d badge uses the second core of the ESP32 just to drive the dot matrix display)

    Bart Huylebroeck BE [9 days ago]
    My aim would be to make a cool programmable name badge. So to save money, I’m happy to drop features like accelerometer (€.5 ? surprisingly expensive!) and servo control. If other coaches want to do more with the badge, let’s discuss. If we remain close enough to €10 pp I believe I can commit an order of 200 pieces.

    Bart Huylebroeck BE [9 days ago]
    I’m curious: what would be the added value of the HT16K33? Just to free processing power on the ESP32? Or would it make the actual code look a lot simpler?

    WimVG [9 days ago]
    Less processing overhead + more dimming options. You could even get away with using an ESP8266 instead of a ESP32 then.

    WimVG [9 days ago]
    The prices I’m referring to are the prices we paid for the components used in the Fri3d badge (volume of 700 pieces)

    Bart Huylebroeck BE [9 days ago]
    I think we can get to 700 pieces if we open it up to the international CoderDojo community. Do the badges come fully assembled?

    WimVG [9 days ago]
    The assembly is done by Dekimo in Belgium (the company I work for) we sponsor the assembly cost. I can check afterwards what the assembly cost is. I also have a good contact in CN which does assembly work for me (and will probably be a lot cheaper :wink: )

    CoderDojo Halle [6:40 PM]
    I like the idea, very much :slightly_smiling_face:. Might be able to help out with development of the software if needed

    Stijn Lemmens [10:13 PM]
    I like the idea. If they’re returned Lubbeek could do with 30-35 of these. It may be a good idea to look at the cafeteria budget to keep things affordable.

Log in to reply

Looks like your connection to CoderDojo Forum was lost, please wait while we try to reconnect.