Author: Lewin Day

3334 Articles

Custom Bedroom Lighting Controlled By Alexa

August 2, 2025 by 3 Comments

[Arkandas] had a problem. They liked reading in bed, but their bedroom lamps weren’t cutting it—either too bright and direct, or too dim and diffuse. The solution was custom lighting, and a new project began.

The concept was simple—build a custom controller for a set of addressable LED lighting strips that would be installed in the bedroom. Specifically, in the headboard of the bed, providing controllable light directly where it was needed. The strips themselves were installed in aluminum channel with plastic diffusers to give a nice smooth light. [Arkandas] then tasked an ESP32 to control the strips, using the FastLED library to work with WS2812B LEDs, and also the Adafruit NeoPixel library for using SK6812 LEDs and their extra white channel. The ESP32 was set up to provide a web interface for direct control over the local network. [Arkandas] also made good use of the FauxmoESP library to enable the device to be controlled via Amazon Alexa, which fit nicely into their existing smarthome setup. Files are on Github for the curious.

The final build works well, creating a soft light in the habitable area of the bed that can also be readily controlled via voice commands or via web. We’ve seen the ESP32 do other great feats in this arena before, too, albeit of the more colorful variety. Meanwhile, if you’re cooking up your own smart lighting solutions, don’t hesitate to tell the tipsline!

You Can Make Your Own Floppy Drive Cleaning Disks

August 1, 2025 by 11 Comments

Once upon a time, you could buy floppy drive cleaning disks at just about any stationary or computer store. These days, they’re harder to find. If you want to build one yourself, though, you might do well to follow [Gammitin]’s fine example.

[Gammitin] has been down this road before, having built head cleaning disks before. This time, a US patent was the inspiration. It basically indicated that the spinning cleaning disc inside should be made of spunbonded polyester or spunbonded olefin (such as Dupont Tyvek)—so those materials were sought out.

The project began with [Gammitin] disassembling a standard floppy disk down to its bare components. The spindle was then separated from the magnetic platter, and refitted with a disc of Tyvek material using super glue. The disk housing was then glued back together with more super glue, and labelled as a “Floppy Cleaning Disk.” Using the disk is as simple as putting a few drops of isopropyl alcohol on the Tyvek material, and inserting it into a drive. [Gammitin] tested it with an old Olivetti machine, and found it cleaned up the heads nicely.

Sometimes, when a commercial product ceases to exist, you can just make your own at home. This is a great example of that ethos. If you’re cooking up your own tools and accessories to keep your old machines running, we’d love to hear all about it on the tipsline!

2025 One-Hertz Challenge: The Flip Disc Clock

August 1, 2025 by 1 Comment

Do you like buses, or do you just like the flippy-flappy displays they use to show route information? Either way, you’ll probably love the flip-disc clock created by [David Plass].

The build is based around four seven-segment flip disc displays. The modules in question are from Flipo.io. They use a hefty 0.5 amp pulse to create a magnetic field strong enough to flip the discs from one side to the other with coils placed underneath the fluro/black flipdots themselves. The modules are controlled by a Wemos D1, which uses Wi-Fi to query a NTP server to keep accurate time. It then drives the necessary segments to display the current time. The whole thing is assembled in what appears to be some kind of kitchen storage tub.

Notably, the clock flips a couple dots once every second to meet the requirements of our One-Hertz Challenge. This also makes it obvious that the clock is working when it would otherwise be static. However, [David] notes commenting out that part of the code at times, as it can be quite loud!

This clock has got fluro dots, it’s well-executed, and it’s a fine entry to the 2025 One-Hertz Challenge. We’ve also previously explored how these beautiful displays work in detail, too. Meanwhile, if you’re busy repurposing some other kind of mechanical display technology, don’t hesitate to let us know!

 

 

 

2025 Hackaday One Hertz Challenge

 

DIY MP3 Player Inspired By The IPod

August 1, 2025 by 6 Comments

These days, the personal MP3 player has been largely replaced by the the smartphone. However, [Justinas Petkauskas] still appreciates the iPod for its tactility and portability, and wanted to bring that vibe back. Enter JPL.mp3

The build is based around the ESP32-S3 microcontroller. It’s hooked up with a PCM5102 DAC hooked up over I2S to provide quality audio, along with a micro SD card interface for music storage, and a small IPS LCD. The best feature, though? The mechanical click-wheel which provides a very tactile way to scroll and interact with the user interface. Everything is assembled into a neat 3D printed case, with a custom four-layer PCB lacing all the electronics together.

On the software side, [Justinas] cooked up some custom software for organizing music on the device using a SQLite database. As he primarily listens to classical music, the software features fields for composer/piece and conductor, orchestra, or performer.

[Justinas] calls the final build “chunky, but nevertheless functional” and notes it is “vaguely reminiscent of classic iPods.” We can definitely see the fun in building your own personalized version of a much-enjoyed commercial product, for sure. Meanwhile, if you’re cooking up your own similar hardware, we’d certainly love to hear about it.

2025 One Hertz Challenge: 4-Function Frequency Counter

July 31, 2025 by 1 Comment

Frequency! It’s an important thing to measure, which is why [Jacques Pelletier] built a frequency counter some time ago. The four-function unit is humble, capable, and also an entry into our 2025 One Hertz Challenge!

The build began “a long while ago when electronic parts were still available in local stores,” notes Jacques, dating the project somewhat. The manner of construction, too, is thoroughly old-school. The project case and the sweet red digits are both classic, but so is what’s inside. The counter is based around 4553 BCD counter chips and 4511 decoder ICs. Laced together, the logic both counts frequency in binary-coded decimal and then converts that into the right set of signals to drive the 7-segment displays. Sample time is either 1 Hz or 0.1 Hz, which is derived from an 8MHz oscillator. It can act as a frequency meter, period meter, chronometer, or a basic counter. The whole build is all raw logic chips, there are no microprocessors or microcontrollers involved.

It just goes to show, you can build plenty of useful things without relying on code and RAM and all that nonsense. You just need some CMOS chips and a bucket of smarts to get the job done!

2025 Hackaday One Hertz Challenge

2025 One-Hertz Challenge: A Software-Only AM Radio Transmitter

July 30, 2025 by 10 Comments

We’ve been loving the variety of entries to the 2025 One-Hertz Challenge. Many a clock has been entered, to be sure, but also some projects that step well outside simple timekeeping. Case in point, this AM transmitter from [oldradiofixer.]

The software-only transmitter uses an ATTiny85 processor to output an AM radio signal in the broadcast band. It transmits a simple melody that you can tune in on any old radio you might have lying around the house. Achieving this was simple. [oldradiofixer] set up the cheap microcontroller to toggle pin PB0 at 1 MHz to create an RF carrier. Further code then turns the 1MHz carrier on and off at varying rates to play the four notes—G#, A, G#, and E—of the Twilight Zone theme. This is set up to repeat every second—hence, it’s a perfectly valid entry to the 2025 One-Hertz Challenge!

It’s a simple project, but one that demonstrates the basics of AM radio transmission quite well. The microcontroller may not put out a powerful transmission, but it’s funny to think just how easy it is to generate a broadcast AM signal with a bit of software and a length of wire hanging off one pin. Video after the break.

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2025 One-Hertz Challenge: Fixing The Clock That Once Synced The World

July 29, 2025 by 5 Comments

The HP 115BR is not one of the most well-known products from Hewlett-Packard. And yet, it was remarkably important nonetheless. This hardware once synced time around the world. Now, for our 2025 One-Hertz Challenge, [curiousmarc] has taken on the job of restoring it. 

The HP 115BR itself was not used alone, but in concert with the HP5060A atomic clock. The latter would output a 100 KHz reference output. It was the job of the HP 115BR to divide this frequency down to provide a superbly accurate 1-second tick.

The example on [curiousmarc]’s bench showed up in poor shape. It was “very broken,” and he reported that it had also previously been hacked to some degree. However, he has been able to restore it to proper functionality, including the special modification for continuous tick adjustment, as used in the 1964 flying atomic clock experiment. He was even able to sync it to NIST’s current atomic clock signal from Fort Collins using the WWW radio signal.

We’ve seen plenty of old HP metal restored over the years; it’s always pleasant to see how well things were built back in the day. Video after the break.

Continue reading “2025 One-Hertz Challenge: Fixing The Clock That Once Synced The World” →