A Musically-Reactive LED Christmas Tree

December 10, 2025 by Lewin Day 4 Comments

Regular Christmas trees don’t emit light, nor do they react to music. If you want both things in a holiday decoration, consider this build from [dbmaking].

An ESP32-D1 mini runs the show here. It’s hooked up to a strip of WS2812B addressable LEDs. The LED strip is placed on a wooden frame resembling the shape of a traditional Christmas tree. Ping-pong balls are then stacked inside the wooden frame such that they act as a light diffuser for the LEDs behind. The microcontroller is also hooked up to an INMP441 omnidirectional MEMS microphone module. This allows the ESP32 to detect sound and flash the LEDs in time, creating a colorful display that reacts to music. This is achieved by using the WLED web installer to set the display up in a sound reactive mode.

It’s a fun build, and we’d love to tinker around with coding more advanced visualizer effects for a build like this. We’ve seen builds that go the other way, too, by toning down excessive blinkiness in Christmas decorations.

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Build Yourself A Graphing Weather Display

December 8, 2025 by Lewin Day 5 Comments

These days, Internet connectivity is ubiquitous, so you can look up live weather data on just about any device around you. Regardless, [Jozerworx] wanted a simple, clean, independent weather display, and came up with this simple design.

The build is based on the Lilygo T5 EPD devboard, which combines an ESP32-S3 microcontroller with a nice 4.7-inch e-paper display. This display has the benefit that it only uses power when it’s being updated, making it particularly suitable to run off a battery for extended periods of time. Meanwhile, the ESP32 and its inbuilt Wi-Fi connectivity allow it to query the internet for updated weather forecasts. Weather data is sourced via the OpenWeather API, which [Jozerworx] notes comes with the caveat of requiring an API key. It’s a little fussy, but if you want good weather data, there are few easier ways to get it. The display shows a forecast for the next five days, while also showing graphs of ambient temperature and humidity along with useful information like the sunset and sunrise schedule.

Files are on Github for those eager to learn more. [Jozerworx] also notes that getting started with the display is particularly easy with the inclusion of a setup mode. This allows the display to act as a Wi-Fi access point with a web page that you use enter your home Wi-Fi connection details.

We’ve featured a great many charming weather displays over the years, too. If you’re working to plot, chart, or even predict the weather—don’t hesitate to show us your cool projects over on the tipsline!

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Retro Style VFO Has Single-Digit Parts Count

December 2, 2025 by Tyler August 9 Comments

Not every project has to be complicated– reinventing the wheel has its place, but sometimes you find a module or two that does exactly what you want, and the project is more than halfway done. That the kind of project [mircemk]’s Simple Retro Style VFO is — it’s a variable frequency oscillator for HAM and other use, built with just a couple of modules.

Strictly speaking, this is all you need for the project.

The modules in question are the SI5351 Clock Generator module, which is a handy bit of kit with its own crystal reference and PLL to generate frequencies up to 150 MHz, and the Elecrow CrowPanel 1.28inch-HMI ESP32 Rotary Display. The ESP32 in the CrowPanel controls the SI5351 module via I2C; control is via the rest of the CrowPanel module. This Rotary Display is a circular touchscreen surrounded by a rotary display, so [mircmk] has all the inputs he needs to control the VFO.

To round out the parts count, he adds an appropriate connector, plus a power switch, red LED and a lithium battery. One could include a battery charger module as well, but [mircmk] didn’t have one on hand. Even if he had, that still keeps the parts count well inside the single digits. If you like video, we’ve embedded his about the project below; if not the write up on Hackaday.io is upto [mircmk]’s typical standard.

People have been using the SI5351 to make VFOs for years now, but the addition of the round display makes for a delightfully retro presentation.

Thanks to [mircmk] for the tip.

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Tiny Little TV Runs On ESP32

November 30, 2025 by Lewin Day 12 Comments

Few of us keep big old cathode ray tubes in the house anymore, but we can still appreciate the form factor of the classic TV. Indeed, the Tinytron from [t0mg] is a neat little tchotchke in this vein — a miniature TV that you could just about fit on a keyring.

[t0mg] wanted this project to be quick and easy to put together. It starts with an ESP32-S3-LCD-1.69 from Waveshare. It’s an all-in-one dev module which combines the microcontroller with a small screen right out of the box. You just have to solder a single six pin header to hook it up with an SD card reader and battery, and you’re done with the electronics. Even the case is a cinch to build, with four 3D printed components that can be spat out of a Prusa MK4S in just half an hour. Programming it can be done via a web browser. Just about the only thing it’s missing is a speaker — this TV is video only.

To watch things on the Tinytron, you just have to prepare them properly and drop them on the SD card. [t0mg] provides a web page for transcoding the video files, although you can do it yourself locally with ffmpeg if you prefer.

If you’re looking for a silly gift for a TV-obsessed friend, you could probably whip up a Tinytron in a couple hours or less. It reminds us of another great project, the tiny Simpsons replica TV that endlessly plays the greatest cartoon on Earth.

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A Holographic Seven-Segment Clock

November 30, 2025 by Lewin Day 6 Comments

Seven-segment displays are one of the most ho-hum ways to display the time. They were cool for a little bit in the 70s, but by now, they’re a little bit old hat. That is, unless you get weird with it. This holographic seven-segment clock from [mosivers] qualifies neatly in that category.

The first step was to make the holographic segment displays, because they’re not really something you can just buy off the shelf. [mosivers] achieved this by using a kit from LitiHolo, which enables you to create holograms by shooting a laser at special holographic film. Only, a few upgrades were made to use the kit with a nicer red diode laser that [mosivers] had on hand for better performance. The seven-segment layouts were carefully recorded on to the film to form the basic numerals of the clock, such that illuminating the films from different angles would light different segments of the numeral. It’s quite involved, but it’s explained well in the build video.

As for the timekeeping side of things, an ESP32 was used, setup to query a network time server to stay accurate. The microcontroller then commands a series of LEDs to light up as needed to illuminate the relevant segments of the holographic film to show the time.

Ultimately, [mosivers] built a cool clock with a look you won’t find anywhere else. It’s a lot more work than just wiring up some classic seven-segment LEDs, but we think the result is worth it. If you fancy other weird seven-segment builds, though, we’ve got plenty of others in the till.

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DIY Light Panels Work With Home Assistant

November 29, 2025 by Lewin Day 2 Comments

There are a few major companies out there building colorful LED panels you can stick on your wall for aesthetic purposes. Most commercial options are pretty expensive, and come with certain limitations in how they can be controlled. [Smart Solutions For Home] has whipped up a flexible DIY design for decorating your walls with light that is altogether more customizable.

In this case, the DIY light panels ape the hexagonal design made popular by brands like Nanoleaf. In this case, each hexagon panel runs an ESP32 microcontroller, which controls a series of WS2812 addressable LEDs. This allows each panel to glow whatever color you like, and they’re arranged in an XY grid to enable you to light individual panels with a range of different geometric effects. The benefit of having a full microcontroller on each panel is that they can act quite independently—each one able to be used as a smart light, an notification display, or even as a physical button, all integrated with Home Assistant.

If you’re a fan of DIY smart home products, these might be right up your alley. They’re supremely flexible and customizable, and can do a lot of things that commercial versions can’t easily replicate. Just don’t ignore the fact that they require a considerable amount of assembly, what with the custom PCBs, 3D printed enclosures, and front diffusers to deal with. That’s just the way the LED wall crumbles.

We’ve seen other similar builds before, too. Why? The simple fact is that a lot of people want cool glowy panels on their wall without having to pay through the nose for them.

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Live Train Departure Screens Keep You Abreast Of Transit Developments

November 28, 2025 by Lewin Day 3 Comments

If you want to know when the train is coming, you could pull up a webpage on your phone, or walk all the way to the station to look at the displays there. Or, like [eastfamilyreddish], you could build a neat little train info display to decorate your desktop instead.

The build is based on the work of [gadec-uk]—who developed a train information display some time ago. It’s based around an ESP32 D1 Mini, paired with a 256 x 64 OLED screen to display relevant train information. It accesses a National Rail API for train status information—known as the Darwin LDBWS (Live Departure Board Webservice). Configuration is via a web GUI hosted by the ESP32 itself.

[eastfamilyreddish] took the concept further by adapting this hardware into a more pleasing form. The ESP32 and OLED screen are built into a neat little hanging sign setup that apes one you might expect to see at a real railway station. You might expect that 3D printing was involved, but instead, this was achieved with lasercut parts and resin casting to create something with a beautiful finish. They even went so far as to include a wireless phone charging module in the base, making the device extra useful to really earn its place on the desktop.

The fact is, around these parts we love both trains and the displays you find around them. If you’ve got a railway-adjacent project, or you’ve just built your own awesome railway, don’t hesitate to let us know on the tipsline!