Building A Desk Display For Time And Weather Data

October 2, 2025 by Lewin Day 19 Comments

Just about every laptop, desktop, and smartphone in your life can tell you the date, time, and current weather predictions. However, sometimes it’s nice to have simple data displayed on a bespoke device. That’s what inspired [Mario] to create ESPTimeCast.

As you might have guessed by the name, the project is designed around the ESP32 and ESP8266 microcontrollers; either one is up to the task of running the show here. Both come with Wi-Fi connectivity out of the box, which makes it easy for them to hook up to the Internet to query NTP servers for the time and weather data from OpenWeatherMap. The data is then displayed on an LED matrix display, made up of four 8×8 LED modules and driven with the aid of the MAX7219 IC. Configuration is handled over a simple web interface hosted on the device itself. All the parts are wrapped up in a 3D-printed housing that would be very fitting in any home that appreciates the magic of late 60s/early 70s decor.

Hackers love building clocks, weather stations, and other useful information displays. We’ve seen a great many examples over the years. If you’re cooking up your own neat project in this area, don’t hesitate to let us know!

“Simplest” Oscilloscope Is A Cunning Vector Display

September 20, 2025 by Tyler August 18 Comments

Superlatives are tricky things. [mircemk]’s guide “How to make Simplest ever Oscilloscope Clock” falls into that category. It’s that word, simplest. Certainly, this is an oscilloscope clock, and a nice one. But is it simple?

There’s a nice oscilloscope circuit with a cute 2″ 5LO38I CRT and EF80 tubes for horizontal and vertical deflection that we’d say is pretty simple. (It’s based on an earlier DIY oscilloscope project [mircemk] did.) The bill of materials is remarkably sparse– but it’s modules that do it. One entry is a DC-DC step up supply to get the needed HV. Another is a LM317 to get 6.3 V to heat the tubes. The modules make for a very simple BOM, but on another level, there’s quite a bit of complex engineering in those little modules.

When we get to the “clock” part of the oscilloscope clock, that quandary goes into overdrive. There’s only one line on the BOM, so that’s very simple. On the other hand, it’s an ESP32. Depending on your perspective, that’s not simple at all. It’s a microcomputer, or at least something that can play at emulating one.

Oh, in the ways that matter to a maker — parts count, time, and effort, this oscilloscope clock is very simple. The fact that its actually a vector display for a powerful little micro just adds to the versatility of the build. We absolutely love it, to be honest. Still, the idea that you can have millions of transistors in a simple project — never mind the “simplest ever” — well, it just seems weird on some level when you think about it.

It all comes back to what counts as “simple”. If we’re taking lines on a BOM, arguably this would be even simpler if you used an existing oscilloscope.

Old Projects? Memorialize Them Into Functional Art

September 1, 2025 by Donald Papp 3 Comments

What does one do with old circuit boards and projects? Throwing them out doesn’t feel right, but storage space is at a premium for most of us. [Gregory Charvat] suggests doing what he did: combining them all into a wall-mountable panel in order to memorialize them, creating a functional digital clock in the process. As a side benefit, it frees up storage space!

Everything contributes. If it had lights, they light up. If it had a motor, it moves.

Memorializing and honoring his old hardware is a journey that involved more than just gluing components to a panel and hanging it on the wall. [Gregory] went through his old projects one by one, doing repairs where necessary and modifying as required to ensure that each unit could power up, and did something once it did. Composition-wise, earlier projects (some from childhood) are mounted near the bottom. The higher up on the panel, the more recent the project.

As mentioned, the whole panel is more than just a collage of vintage hardware — it functions as a digital clock, complete with seven-segment LED displays and a sheet metal panel festooned with salvaged controls. Behind it all, an Arduino MEGA takes care of running the show.

Creating it was clearly a nostalgic journey for [Gregory], resulting in a piece that celebrates and showcases his hardware work into something functional that seems to have a life of its own. You can get a closer look in the video embedded below the page break.

This really seems like a rewarding way to memorialize one’s old projects, and maybe even help let go of unfinished ones.

And of course, we’re also a fan of the way it frees up space. After all, many of us do not thrive in clutter and our own [Gerrit Coetzee] has some guidance and advice on controlling it.

Continue reading “Old Projects? Memorialize Them Into Functional Art” →

Lightning Talks On Time, With This Device

August 31, 2025 by Jenny List 3 Comments

Ask a Hackaday scribe who’s helped run the lightning talks at one of our events, and they’ll tell you that keeping the speakers on time is a challenge. Conversely if the staffer is trying to indicate to the speaker how much time they have left, it must be difficult from the podium to keep track while delivering your talk. Fortunately there’s [makeTVee] waiting in the wings with a solution, a cube whose faces each have a custom 5×7 LED matrix on them. The countdown is clear and unambiguous, and should provide no distractions.

The brains behind it all is a XIAO nRF52840 Sense board using the Zephyr RTOS, the LEDs are WS2812s on their own PCBs, and the party piece is only revealed at the end of the countdown. A tilt mechanism triggered by a servo releases a ball bearing down a track, where it hits a telephone bell and provides a very audible reminder to the speaker. The result saw action during the lightning talks at the Hackaday Europe event earlier in the year, but it’s taken a while for the write-up to make it online.

Continue reading “Lightning Talks On Time, With This Device” →

This Soviet-Style Clock Uses Homemade Nixie Tubes And Glowing Logic

August 31, 2025 by Tyler August 11 Comments

The Neon glow of a Nixie tube makes for an attractive clock, but that’s not enough neon for some people. [Changliang Li] is apparently one of those people, because he’s using soviet-era cold-cathode tubes as the logic for his “Soviet-Era Style Clock”

Aside from the nixies for display, the key component you see working in this beautiful machine are the MTX-90 cold cathode thyratrons, which look rather like neon tubes in action. That’s because they essentially are, just with an extra trigger electrode (that this circuit doesn’t use). The neon tubes are combined into a loop counter, which translates the 50 Hz mains circuit in to seconds, minutes, and hours. The circuit is not original to this project, and indeed was once common to electronics books. The version used in this project is credited to [PA3FWM].

The Nixie tubes are new-made by [Sadudu] of iNixie labs, and we get a fascinating look in how they are made. (Tubemaking starts at around 1:37 in the video below.) It looks like a fiber laser is used to cut out glow elements for the tube, which is then encapsulated on a device which appears to be based around a lathe.

The cold-cathode tubes used as logic rely on ambient light or background radiation to start reliably, since the trigger electrode is left floating. In order to ensure reliable switching from the thyratrons, [Changliang Li] includes a surplus smoke detector source to ensure sufficient ionization. (The video seems to imply the MTX-90 was seeded with radioisotopes that have since decayed, but we could find no evidence for this claim. Comment if you know more.)

The end result is attractive and rather hypnotic. (Jump to 3:37 to see the clock in action.) If you want to know more about this sort of use for neon lamps (and the Soviet MTX-90) we featured a deeper dive a while back.

Thanks to [Changliang Li] for the incandescent tip. If one of your bright ideas has had a glow up into a project, don’t hesitate to share it on our tips line.

Continue reading “This Soviet-Style Clock Uses Homemade Nixie Tubes And Glowing Logic” →

Candle Oscillator Really Heats Things Up

August 23, 2025 by Jenny List 11 Comments

As the timebase for a clock, almost anything with a periodic oscillation can be used. Traditionally, that meant a pendulum, but in our time, we’ve seen plenty of others. Perhaps none as unusual as [Tim]’s candle flicker clock, though.

Candles are known for their flickering, a property of the wick and the fuel supply that candle manufacturers have gone to great lengths to mitigate. If you bring several of them together, they will have a significant flicker, with a surprisingly consistent 9.9 Hz frequency. This is the timebase for the clock, with the capacitance of the flame being sensed by a wire connected to a CH32 microcontroller, and processed to produce the required timing.

We like this project, and consider it a shame that it’s not an entry in our One Hertz Challenge. Oddly, though, it’s not the first candle-based oscillator we’ve seen; they can even be turned into active electronic devices.

2025 One Hertz Challenge: Atomic Decay Clock Is Accurate But Not Precise

August 19, 2025 by Adam Zeloof 7 Comments

At this point, atomic clocks are old news. They’ve been quietly keeping our world on schedule for decades now, and have been through several iterations with each generation gaining more accuracy. They generally all work under the same physical principle though — a radio signal stimulates a gas at a specific frequency, and the response of the gas is used to tune the frequency. This yields high accuracy and high precision — the spacing between each “tick” of an atomic clock doesn’t vary by much, and the ticks cumulatively track the time with very little drift.

All of this had [alnwlsn] thinking about whether he could make an “atomic” clock that measures actual radioactive decay, rather than relying on the hyperfine transition states of atoms. Frustratingly, most of the radioactive materials that are readily available have pretty long half-lives — on the order of decades or centuries. Trying to quantify small changes in the energy output of such a sample over the course of seconds or minutes would be impossible, so he decided to focus on the byproduct of decay — the particles being emitted.

He used a microcontroller to count clicks from a Geiger-Müller tube, and used the count to calculate elapsed time by multiplying by a calibration factor (the expected number of clicks per second). While this is wildly inaccurate in the short term (he’s actually used the same system to generate random numbers), over time it smooths out and can provide a meaningful reading. After one year of continuous operation, the counter was only off by about 26 minutes, or 4.4 seconds per day. That’s better than most mechanical wristwatches (though a traditional Rubidium atomic clock would be less than six milliseconds off, and NIST’s Strontium clock would be within 6.67×10^-11 seconds).

The end result is a probabilistic radiometric timepiece that has style (he even built a clock face with hands, rather than just displaying the time on an LCD). Better yet, it’s got a status page where you can check on on how it’s running. We’ve seen quite a few atomic clocks over the years, but this one is unique and a great entry into the 2025 One Hertz Challenge.