Mankind has been using water to mark the passage of time for thousands of years. From dripping stone pots in Ancient Egypt to the more mechanically-complicated Greco-Roman Clepsydrae, the history of timekeeping is a wet one — and it makes sense. As an incompressible fluid, water flows in very predictable patterns. If you fill a […]
Wall clocks! Are they very accurate? Well, sometimes they are, and sometimes they lose minutes a day. If you’ve got one that needs calibrating, you might like this device from [Lauri Pirttiaho]. Most cheap wall clocks use very similar mechanisms based around the Lavet-type stepper motor. These are usually driven by a chip-on-board oscillator that […]
This eye-catching entry to the One Hertz Challenge pairs vintage LED indicators with a modern RPi board to create a one-of-a-kind clock. The RPI TinynumberHat9 by [Andrew] brings back the beautiful interface from high end electronics of the past. This project is centered around the red AL304 and green ALS314V 7-segment display chips. These 7-segment […]
Just about every electronic device has some silicon semiconductors inside these days—from transistors to diodes to integrated circuits. [Charles] is trying to build a “No-Silicon digital clock” that used none of these parts. It looks like [Charles] is on the way to success, but one might like to point out an amusing technicality. Let’s dive […]
Most of us know that a quartz clock uses a higher frequency crystal oscillator and a chain of divider circuits to generate a 1 Hz pulse train. It’s usual to have a 32.768 kHz crystal and a 15-stage divider chain, which in turn normally sits inside an integrated circuit. Not so for [Bobricius], who’s created […]
One of the categories we chose for the One Hertz Challenge is “Could Have Used a 555.” What about when you couldn’t have, but did anyway? The 555 is famously easy to use, but not exactly the most accurate timer out there — one “ticking” at 1 Hz will pulse just about once per second […]
We’ve seen our share of blinking light projects around here; most are fairly straightforward small projects, but this entry to the 2025 One Hertz Challenge is the polar opposite of that approach. [Peter] sent in this awesome tower of 16bit relay CPU power blinking a light every second. There’s a lot to take in on […]
We did explicitly ask for projects that use a 555 timer for the One Hertz Challenge, but we weren’t expecting the 555 to be the project. Yet, here we are, with [matt venn]’s Open Source 1Hz Blinky, that blinks a light with a 555 timer… but not one you’d get from Digikey. Hooking a 555 […]
We’ve all felt the frustration of cheap consumer electronics — especially when they aren’t actually cheap. How many of us have said “Who designed this crap? I could do better with an Arduino!” while resisting the urge to drop that new smart doorbell in the garbage disposal? It’s an all-too familiar thought, and when it […]
[Robert Morrison] had an ancient HP 545A logic probe, which was great for debugging SMT projects. The only problem was that being 45 years old, it wasn’t quite up to scratch when it came to debugging today’s faster circuitry. Thus, he hacked it to do better, and entered it in our 2025 One Hertz Challenge […]