A chicken's egg with many holes glows beneath a glass globe set atop an inverted wooden bowl.

Glowing Egg Is A One-Oeuf Solution For Tracking Cycles

September 7, 2024 by Kristina Panos 28 Comments

Look, if something happened to you every three weeks or so to basically turn you into a different person and factored heavily into whether any new humans were created, you’d probably want to keep abreast of the schedule, yeah? Yeah. So, while there are, of course, a ton of ways to do this with your phone, most of those apps do gross things with your data. Are you angry yet?

[Jakoba the Online Witch] certainly was, or if not angry, at least annoyed. So she built a glowing egg timer, which shines a different color based on current point in her cycle, to let her know when she is fertile and expecting Aunt Flo.

The coolest part is that this is an actual egg from one of [Jakoba]’s backyard chickens. No. The coolest part is how she was able to make so many holes without breaking it. (It took four tries.)

After bleaching the insides, the egg was ready to glow. As [Jakoba] says, the guts are simple — just a Wemos D1 Mini ESP8266, a WS2812 LED, and a heatsink. The enclosure consists of an inverted peanut bowl with a glass ornament hot-glued in place.

Once it was put together, all she had to do was add it in Home Assistant and use the current calendar state to trigger services from the YAML configuration.

Would you prefer an on-body solution? Here’s an earring that tracks temperature.

Thermal Earring Tracks Body Temperature

February 13, 2024 by Kristina Panos 11 Comments

If you want to constantly measure body temperature to track things like ovulation, you usually have to wear something around your wrist or finger in the form of a smartwatch or ring. Well, what if you can’t or don’t want to adorn yourself this way? Then there’s the thermal earring.

Developed at the University of Washington, the thermal earring is quite small and unobtrusive compared to a smartwatch. Sure, it dangles, but that’s so it can measure ambient temperature for comparison’s sake.

You don’t even need to have pierced ears — the earring attaches to the lobe magnetically. And yeah, the earring can be decorated to hide the circuitry, but you know we would rock the bare boards.

The earring uses BLE to transmit readings throughout the day, and of course goes into sleep mode between transmissions to save power. Coincidentally, it runs for 28 days per charge, which is the length of the average menstrual cycle. While the earring at this time merely “shows promise” as a means of monitoring stress and ovulation, it did outperform a smartwatch at measuring skin temperature while the wearers were at rest.

This is definitely not the only pair of earrings we’ve got around here. These art deco earrings use flexible PCBs, and this pair will light up the night.