Qron0b: a Minimalist, Low-Power BCD Wristwatch
Over the decades we have seen many DIY clocks and wrist watches presented, but few are as likely to get you either drawing in the crowds, or quietly snickered at behind your back, as a binary watch of some description does. A wrist watch like [qewer]’s qron0b project which also uses BCD encoding to display the current time is among our more rare project types here, with us having to go all the way back to 2018 for a similar project as well as a BCD desk clock.
As is typical, a single CR2032 coin cell powers the entire PCB, with an ATtiny24A or compatible as the MCU, a DS1302 RTC and the requisite 4×4 LED matrix to display the hours and minutes. Technically three LEDs are unneeded here, but it looks nicely symmetrical this way, and the extra LEDs can be used for other tasks as the firmware is expanded from the current setting and reading of the time.
The AVR C firmware can be found in the above linked GitHub repository, along with the KiCad PCB project and FreeCAD design files for the watch body. The body accepts a 22 mm GT2/GT3-style watch strap to complete the assembly. With a single CR2032 you’re assured of at least a few months of runtime.
[2026-01-05] Epifania Sbermuz @ Libera Collina di Castello
Epifania Sbermuz
Libera Collina di Castello - Piazza Santa Maria in Passione
(lunedì, 5 gennaio 20:30)
Il 5 gennaio torniamo alla Libera Collina di Castello di Genova con:
😵 @jagwari___ international space station/garageband music da levante
🤪 @linguini_band noise irrequieto (MI)
☠️ @monteverde.noise rumore, noise (GE)
💥 @spirytus96_ neosoul funky musica (GE)
🎫 Ingresso e bar: OFFERTA LIBERA!!! Inizio musica 20:30
👊🏼 Preserviamo gli spazi sociali occupati autogestiti, contro la gentrificazione e la turistificazione di massa!
Collettivo Sbermuz
Adding Solar Power to an Electric Tractor
In my country, we have a saying: the sun is a deadly lazer. Well, it’s not so much a folk saying as a meme, and not so much in one country as “the internet”. In any case, [LiamTronix] was feeling those cancer rays this harvest season when running his electric tractor, and realized that– since he’s already charging it with ground-mounted solar panels anyway–if he’s going to build a roof for his ride, he might as well make charge the batteries.
Another bonus is safety: the old Massey-Ferguson at the heart of the electric tractor build didn’t come with any rollover protection from the factory back in the 1960s. Since having however many tons of tractor roll onto you was bad enough before it got a big hefty battery pack, we heartily approve of including a roll cage in this build. Speaking of battery packs, he’s taking this chance to upgrade to a larger LiFePo pack from the LiIon pack he installed when we first featured this conversion in 2024.
Atop the new roll cage, and above the new battery, [Liam] installed four second-hand 225 W solar panels. Since that’s under 1kW even if the panels have not degraded, the tractor isn’t going to be getting much charge as it runs. In the northern winter, [Liam] is only able to pull 80 W from the set. That’s not getting much work done, but who wants a tractor without a cab or heater when it’s below freezing? In the summer it’s a much better story, and [Liam] estimates that the roof-mounted panels should provide all of the energy needed to run the tractor for the couple hours a day he expects to use it.
If you’re wondering how practical all this is, yes, it can farm — we covered [Liam] putting the project through its paces in early 2025.