Becky Stern, David Cranor, And A CT Scanner Vs The Oura Ring

May 10, 2022 by 7 Comments

If you wonder how it’s possible to fit a fitness tracker into a ring, well, you’re not alone. [Becky Stern] sent one off to get CT scanned, went at it with a rotary tool, and then she made a video about it with [David Cranor]. (Video embedded below.)

While it’s super cool that you can do a teardown without tearing anything down these days — thanks to the CT scan — most of the analysis is done on a cut-up version of the thing through a normal stereo microscope. Still, the ability to then flip over to a 3D CT scan of the thing is nice.

We absolutely concur with [Becky] and [David] that it’s astounding how much was fit into very little space. Somewhere along the way, [David] muses that the electrical, mechanical, and software design teams must have all worked tightly together on this project to pull it off, and it shows. All along, there’s a nice running dialog on how you know what you’re looking at when tearing at a new device, and it’s nice to look over their shoulders.

Then there’s the bit where [Becky] shows you what a lithium-ion battery pack looks like when you cut it in half. She says it was already mostly discharged, and she didn’t burst into flames. But take it easy out there! (Also, make sure you take your hot xylene out on the patio.)

X-ray machines are of course just the coolest thing when doing a teardown. We’ve seen them used from fixing multimeters to simply looking at servo motors.

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Yule-Inspired Tool Time With [Becky Stern]

December 19, 2014 by 46 Comments

And now for something completely different: [Becky Stern]’s musical tour of her favorite tools around the Adafruit factory is the best holiday tune we’ve heard since The Waitresses’ “Christmas Wrapping”. Of course, good tools are near and dear to us as well, and we found ourselves nodding frequently in agreement and smiling as broadly as [Billie, Ruby, and Gus], the anthropomorphic LED backup singers.

In other Adafruity news, it looks like their new Samsung SM482 pick and place machine was given the gift of eyes as big as pizza pies. What tools would you like to see under the tree, leaning against the Festivus pole, or all wrapped up a safe distance from the menorah this year? Do tell.

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PCBs of two continuous glucose monitors

Peeking At Poking Health Tech: The G7 And The Libre 3

April 29, 2025 by 9 Comments

Continuous glucose meters (CGMs) aren’t just widgets for the wellness crowd. For many, CGMs are real-time feedback machines for the body, offering glucose trendlines that help people rethink how they eat. They allow diabetics to continue their daily life without stabbing their fingertips several times a day, in the most inconvenient places. This video by [Becky Stern] is all about comparing two of the most popular continuous glucose monitors (CGMs): the Abbott Libre 3 and the Dexcom G7.

Both the Libre 3 and the G7 come with spring-loaded applicators and stick to the upper arm. At first glance they seem similar, but the differences run deep. The Libre 3 is the minimalist of both: two plastic discs sandwiching the electronics. The G7, in contrast, features an over-molded shell that suggests a higher production cost, and perhaps, greater robustness. The G7 needs a button push to engage, which users describe as slightly clumsy compared to the Libre’s simpler poke-and-go design. The nuance: G7’s ten-day lifespan means more waste than the fourteen-day Libre, yet the former allows for longer submersion in water, if that’s your passion.

While these devices are primarily intended for people with diabetes, they’ve quietly been adopted by a growing tribe of biohackers and curious minds who are eager to explore their own metabolic quirks. In February, we featured a dissection of the Stelo CGM, cracking open its secrets layer by layer.

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Wearables queen [Becky Stern] with a microcontroller and a speaker. And a skull!

Wearable Tech Tips Directly From The Queen

February 2, 2025 by 8 Comments

What’s the only thing cooler than building something electronic? That’s right — wearing it proudly for all to see.

But maybe you’re not into wearables. Maybe it’s because you’re afraid of sewing, or simply scared that you won’t be able to launder that blinkenshirt you’ve always wanted to make. Well, the undisputed queen of wearables — [Becky Stern] — has a bunch of beginner tips for making DIY wearables. She’s created dozens and dozens of wearable projects and matching tutorials over the years and has graced these pages many times.

As [Becky] points out, once you have your idea sorted, the next thing you need is the tools to get the skills to do the parts you don’t know how to do yet. Even if that’s almost all of it, then this is the guide for you. Importantly, [Becky] reminds us that we should only bite off what we can chew, and that ready-made modules and such are perfectly fine.

There are some tips here that may surprise you. For instance, [Becky] recommends against conductive thread for beginners who already know how to sew by hand, largely because of power delivery and other issues. She also is somewhat anti-lithium battery pouch, preferring instead to use a couple of AAs or a USB battery bank for the renewability aspect.

Be sure to check out the video after the break, which has these tips and more.
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Your Cat Needs Its Own TV

March 10, 2024 by 21 Comments

Cats are wonderful creatures to have around, and they provide us with hours of entertainment. So why not do a little something to entertain them in return? That’s exactly what [Becky Stern] did by making a cat TV that shows YouTube videos of birds and other cat-approved content. Not all cats seem to care about TV, but [Becky]’s cat Benchley really gets into it.

As you may have guessed, this is a fairly simple build, consisting largely of a Raspberry Pi, a speaker, and a screen — a 5″ HDMI LCD display to be exact. Seems like a nice size for cats. After getting the cat-puter up and running, [Becky] set about designing a 3D-printed enclosure to turn it into a TV. The first draft looked great in marble-effect filament, but lacked breathing holes for the Pi, so the final version has a nice honeycomb pattern that is too small for curious cat paws to fit through.

What their paws can do is accidentally pause the video via the touch screen, so [Becky] swapped the USB cable for a charge-only to prevent this. Be sure to check out the build video after the break, because there is plenty of cat cuteness to be had. [Benchley] was so into it that he went looking around back for cats and squirrels inside the box.

Would you rather not encourage your cats to lie about the house watching TV all day? Make them play piano for their dinner.

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Making A Kit-Kat Clock Even Creepier

December 19, 2023 by 10 Comments

If there’s anything as American as baseball and apple pie, it’s gotta be the Kit-Kat clock in the kitchen. For the unfamiliar, the Kit-Kat clock is special in that its pendulum tail and eyes move back and forth with each passing second. They’re equal parts cute and creepy.

But not this particular Kit-Kat, not once [Becky Stern] got a hold of it. The cute/creepy scales have been tipped, because the eyes of this Kat follow you around the room. “You” in this case is fellow maker [Xyla Foxlin], whom [Becky] drew in the Maker Secret Santa pool. See, [Xyla] loves cats, but is deathly allergic to them. So really, what better gift is there?

In order to make this happen, [Becky] started by disconnecting the long lever that link the eyes and the tail, which move together, and connected a servo horn to the eyes. [Becky] drilled out the nose in order to fit the camera, which is connected to a Seeed Grove AI Vision board with a Xiao RP2040 piggybacked on top.

While soldering on the servo wires, [Becky] accidentally detached a tiny capacitor from the AI Vision board, but it turns out that it wasn’t critical. Although she only had to write one line of code to get it to work, it ended up working too well, with the eyes darting around really quickly. By making the servo move in timed increments to the new positions, it’s now much more creepy. Be sure to check out the build video after the break.

You know we can’t resist a clock build around here, especially when those clocks are binary.

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Building Penny’s Computer Watch From Inspector Gadget

October 31, 2023 by 4 Comments

When you help your bumbling Uncle Gadget with all kinds of missions, you definitely need a watch that can do it all. Penny’s video watch from Inspector Gadget has a ton of features including video communication with Brain and Chief Quimby, a laser, a magnet, a flashlight, a sonar signal, and much more.

To round out her Penny costume, [Becky Stern] has created a 3D printed version of Penny’s incredibly smart watch. It listens for Penny’s iconic phrase — come in, Brain! — and then loads a new picture of Brain on the rounded rectangle TFT display. Inside the watch is an Arduino Nicla Voice, which has to be one of the tinier machine learning-capable boards out there.

[Becky] created the watch case in Tinkercad and modified a watch band from Printables to fit her wrist. With such a small enclosure to work with, [Becky] ended up using that really flexible 30 AWG silicone-jacketed wire for all the fiddly connections between the Arduino and the screen.

After getting it all wired up to test, she found that the screen was broken, either from pressing it into the enclosure, or having a too-close encounter with a helping hands. Let that be a lesson to you, and check out the build video after the break.

More interested in Uncle Gadget’s goodies? Check out these go-go-Gadget shoes and this propeller backpack for skiers.

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