alt.hn

4/4/2026 at 2:20:21 PM

Show HN: I made open source, zero power PCB hackathon badges

 https://github.com/KaiPereira/Overglade-Badges

by kaipereira

4/5/2026 at 1:03:57 AM

That's very cool.

I have a few ePaper picture frames that don't use any power, and when you tap your phone to them it uses the power-over-NFC to boot itself and update the photo you send to it. It's such a cool idea and something I always felt like could be used more for displays that don't need to update very often.

by sen

4/5/2026 at 6:40:34 AM

This sounds really neat. Is it a commercial product or did you build them yourself?

by larelli

4/5/2026 at 4:28:45 PM

This is so cool. Could you share more about where I could find them?

by nbbaier

4/4/2026 at 10:55:05 PM

How much did they end up costing? We do a similar PCB medallion every year for another event and haven't been able to get quite that fancy due to cost. We usually only manage to get some LEDs and a processor in our lower budget range.

by robertclaus

4/4/2026 at 11:16:13 PM

The total ended up being about $10/badge for 60 (5 for badge, 5 for eink), and we made the mistake of not ordering enough, so we ordered a couple more that were about $1 more expensive each. We bought all the badges from JLC and the prod files are in the repo if you want to see how much they come to in higher order quantity!

by kaipereira

4/5/2026 at 11:16:14 AM

Interesting... RP2040 seems like maybe a bit overkill for a zero power badge. I've participated in writing some software for an RP2040 powered badge for the RVASEC conference in Richmond, VA, for several years, and the RP2040 is really nice to program for, and is quite powerful. https://www.youtube.com/watch?v=A5ZrHAXCFLA

by smcameron

4/5/2026 at 3:40:27 PM

Yeah the RP2040 is a bit overkill, but it's really cheap to get from JLC, easy to prototype FAST and easy if anyone wants to reference the design and create/program their own badges.

I have been looking at some other MCU's like the CH32 for future projects, so if you also have any suggestions for other ones, I'd love to hear them!

by kaipereira

4/6/2026 at 11:47:30 AM

Went to Treehacks at Stanford this Feb and they had PCB badges too! Gotta say these ones are much cooler tho :D

by aditmag

4/6/2026 at 3:32:52 PM

Thanks so much!

by kaipereira

4/5/2026 at 12:46:08 AM

how does "zero-power" work exactly? all power from NFC?

by NooneAtAll3

4/5/2026 at 12:49:59 AM

So the eink holds its state once it’s programmed so you do need an initial program of the badge through USB-C, and then the NFC uses passive RF harvesting.

by kaipereira

4/5/2026 at 12:50:45 AM

yes NFC and with an e-ink display no battery needed from there

by cactacea

4/5/2026 at 2:24:18 AM

Very cool! Quick question: did you use a plugin to generate the NFC antenna?

The routing and layout looks nice. The end result is great! I bet it was satisfying to get it working on the first try.

by bschwindHN

4/5/2026 at 2:50:11 AM

I used https://eds.st.com/antenna/#/ to get an antenna that fit with a target inductance of 4.7uH and then used https://github.com/nideri/nfc_antenna_generator to create the footprint which I slightly modified for the board! You can read a bit more about it in the journal (JOURNAL.md)!

It was really satisfying to get everything working (especially the NFC because I've found RF to be a bit tricky), but the eink logic was actually a bit of gamble, because I broke my only eink while prototyping so the production batch was the first test of the driver. So always carry spare components when designing prototypes!

by kaipereira

4/6/2026 at 4:16:43 AM

Awesome resources, thanks so much!

by bschwindHN

4/5/2026 at 4:06:47 PM

Do you ship internationally, also with complete setup of the hardware?

by moezd

4/5/2026 at 4:16:38 PM

We ordered the PCB's and badges separately, but it's extremely easy to assemble, you just attach the eink on using the FPC connector and the badges are already in a complete setup of the hardware if you get PCBA.

You can make it more fun on yourself if you want to assemble them by hand and it's probably a bit cheaper, and JLC will ship to pretty much anywhere in the world.

by kaipereira

4/5/2026 at 1:09:40 PM

[dead]

by metaPushkin

4/5/2026 at 8:15:55 AM

Not directly related to the submission content, but trying to monitor trends: I understand there's the "no capitalization" one at the start of sentences and for the "I".

Apparently OP is not following this one, but I see that _some_ proper nouns are not capitalized (like github, singapore, overglade...) while others are.

Should I update my userscript to handle an incoming new trend?

by wiether