Wearable Photon

Hi all, just wanted to share a quick update on a prototype we’re working on. At it’s heart is a photon, but we integrated a ton of tech in an already pretty small form factor: #nfc #qi #lipo #vibration #neopixel… It’s used to scan products on a showfloor and fill a shopping cart via our APIs (via webhooks).

Thx for having a look!


@hansamann, NICE job and great application! Are you considering using the P1 module or the castelated Photon? I like the idea of QI charging and that gives me some ideas for an idea of mine. Thanks for sharing and please post updates! :smiley:

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Hi @peekay123, do you think that using the p0 is feasible for a prototype? The 0805 package was hard enough to solder. Also from a dev point of view, how would I use the p0. Would be an interesting challenge that further reduces the size of course.

Next for us right now is a design review, we might change the design to a 3d printed bracelet for example.

The qi charging works, but it is not perfect. When the low charge protection of the lipo kicks in and you start charging the system, it sometimes ends up looping at startup. Let me post some details next week, if the community could help improve this it would be awesome…

@hansamann, I was referring to the P1 since, as a module, it has an integrated antenna and is FCC pre-certified. With the P0, you will need to certify you board since it is an emitter. However, for size, the P0 may be the best choice.

I’ll be looking for your comments on QI charging for sure. The fantastic @BDub can give you more details on the challenges of building the Photon which also uses 0805 parts. As for the community, well I believe its reputation precedes it :wink:

@hansamann, While working with SMD electronics I suggest you get a decent set of tools. I’ve been working with 0402 by using the below and a steady hand.

Also just be cautioned that the FCC certification only applies to devices that are >20cm from the body. Otherwise it will need a different classification as a portable device for body wear, this is for SAR testing. See the below link.

Below is in my tool box:

@wesner0019, thanks for the great info! :grinning:

0805 components are super easy, they practically install themselves.
0603 components are super easy, some attention required.
0402 components are getting small, but YOU CAN DO IT!
0201 components are literally breathable, don’t ingest, but seriously YOU CAN ALSO DO THIS!! However I would stay away from these unless you absolutely need them.

The Photon has all of these, except for 0805, totally able to hand assemble these… we did it!


Sorry, I had to:


I was in fact thinking of this when I CAPPED MY TEXT! :smile:

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The issue still stands that for a wearable, the Photon/P0/P1 would need to be (re)certified, correct?

Hey guys!

We’re currently overhauling our documentation and are going to build in a big section about certifications that will make this all a little clearer. In layman’s terms, though, here are the basics:

  • The Photon is FCC single modular certified
  • The P1 is also FCC single modular certified
  • The P0 is not FCC certified. It could be, although it doesn’t have a built in antenna or some other requirements for single modular certification, so it could only be limited single modular certified.

The basic gist is that, if you take a FCC modular certified product and leave the intentional transmitter portion of the reference design unchanged (while also declaring all new unintentional transmitters and not adding any new intentional transmitters), the path for certified is significantly simplified, and you can piggyback on our certification. At that point, it looks more like a VoC (Verification of Certification) instead of a “from-scratch” FCC cert, which takes less time, money, effort, and documentation.

We’ll do a big post to the community once the docs are updated, and I’ll make sure to highlight that section about certification appropriately!


@will, that’s great news! However, the Particle certification is for at least 20cm from the body, omitting wearables. What then?

Ahhh, sorry. Hopped into the post out of context and didn’t read closely enough, my fault. Since the certification includes stipulations for distance from the body, yes, it would need to be re-certified.

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thx for the great comments. I am wondering if the certification that was brought up affects us for a prototype - I assume not, but of course if we were to create a product, we might have an issue.

For the P1 - if we really wanted to “play” with it, what are the next steps? Buying 10 at once is already a steep curve (high risk) I think… but can I even solder thsi myself, with common tools and without a reflow oven or so?


i don’t think hand soldering is possible with pad all on the underside!

ok, so how does that work :slight_smile: seriously. we don’t have a professional pick & place machine setup etc. … is that next step feasible therefore?

What do you think if we have a breakout board? :slight_smile: I can design one with basic stuff like the buttons and rgb led and 3v3 SMPS

well, the major reason for p1 for me woudl to further optimize the size of the complete prototype. Right now the compinetn with the spark photon is the biggest and fattest part of the prototype. The p1 would bring the height down considerably. A shield or so is not required in my case as I can then just simply use the photon without headers…

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it will be tough though we can solder the P1 on a board with castellated edges and mounted to your board.

Isnt that what we like to call a ‘Photon’ :wink: (apart from the extra storage)?

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