Author: Lewin Day

3515 Articles

A Touchscreen MIDI Controller For The DIY Set

December 7, 2025 by 8 Comments

MIDI controllers are easy to come by these days. Many modern keyboards have USB functionality in this regard, and there are all kinds of pads and gadgets that will spit out MIDI, too. But you might also like to build your own, like this touchscreen design from [Nick Culbertson].

The build takes advantage of a device colloquially called the Cheap Yellow Display. It consists of a 320 x 240 TFT touchscreen combined with a built-in ESP32-WROOM-32, available under the part number ESP32-2432S028R.

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Neat Techniques To Make Interactive Light Sculptures

December 7, 2025 by 21 Comments

[Voria Labs] has created a whole bunch of artworks referred to as Lumanoi Interactive Light Sculptures. A new video explains the hardware behind these beautiful glowing pieces, as well as the magic that makes their interactivity work.

The basic architecture of the Lumanoi pieces starts with a custom main control board, based around the ESP-32-S3-WROOM-2. It’s got two I2C buses onboard, as well as an extension port with some GPIO breakouts. The controller also has lots of protection features and can shut down the whole sculpture if needed. The main control board works in turn with a series of daisy-chained “cell” boards attached via a 20-pin ribbon cable. The cable carries 24-volt power, a bunch of grounds, and LED and UART data that can be passed from cell to cell. The cells are responsible for spitting out data to addressable LEDs that light the sculpture, and also have their own microcontrollers and photodiodes, allowing them to do all kinds of neat tricks.

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The ZX Spectrum Finally Got An FPS

December 7, 2025 by 16 Comments

The ZX Spectrum is known for a lot of things, but it’s not really known for a rich and deep library of FPS titles. However, there is finally such a game for the platform, thanks to [Jakub Trznadel]—and it’s called World of Spells.

Like so many other games of this type, it was inspired by the 3D raycasting techniques made so popular by Wolfenstein 3D back in the day. For that reason, it has a very similar look in some regards, but a very different look in others—the latter mostly due to the characteristic palette available on the ZX Spectrum. A playable FPS is quite a feat to achieve on such limited hardware, but [Jakub] pulled it off well, with the engine able to reach up to 80 frames per second.

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Bridging RTL-433 To Home Assistant

December 6, 2025 by 18 Comments

If you’ve got an RTL-SDR compatible receiver, you’ve probably used it for picking up signals from all kinds of weird things. Now, [Jaron McDaniel] has built a tool to integrate many such devices into the world of Home Assistant.

It’s called RTL-HAOS, and it’s intended to act as a bridge. Whatever you can pick up using the RTL_433 tool, you can set up with Home Assistant using RTL-HAOS. If you’re unfamiliar with RTL_433, it’s a multitalented data receiver for picking up all sorts of stuff on a range of bands using RTL-SDR receivers, as well as a range of other hardware. While it’s most closely associated with products that communicate in the 433 MHz band, it can also work with products that talk in 868 MHz, 315 MHz, 345 MHz, and 915 MHz, assuming your hardware supports it. Out of the box, it’s capable of working with everything from keyless entry systems to thermostats, weather stations, and energy monitors. You can even use it to listen to the tire pressure monitors in your Fiat Abarth 124 Spider, if you’re so inclined.

[Jaron’s] tool integrates these devices nicely into Home Assistant, where they’ll appear automatically thanks to MQTT discovery. It also offers nice signal metrics like RSSI and SNR, so you can determine whether a given link is stable. You can even use multiple RTL-SDR dongles if you’re so inclined. If you’re eager to pull some existing environmental sensors into your smart home, this may prove a very easy way to do it.

The cool thing about Home Assistant is that hackers are always working to integrate more gear into the ecosystem. Oftentimes, they’re far faster and more efficient at doing this than big-name corporations. Meanwhile, if you’re working on your own hacks for this popular smart home platform, we’d probably like to know about it. Be sure to hit up the tips line in due time.

Garage Fridge Gets New DIY Controller

December 5, 2025 by 44 Comments

[Rick] had a problem. His garage refrigerator was tasked with a critical duty—keeping refreshing beverages at low temperature. Unfortunately, it had failed—the condenser was forever running, or not running at all. The beverages were either frozen, or lukewarm, regardless of the thermostat setting. There was nothing for it—the controller had to be rebuilt from scratch.

Thankfully, [Rick]’s junk drawer was obliging. He was able to find an Arduino Uno R4, complete with WiFi connectivity courtesy of the ESP32 microcontroller onboard. This was paired with a DHT11 sensor, which provided temperature and humidity measurements. [Rick] began testing the hardware by spitting out temperature readings on the Uno’s LED matrix.

Once that was working, the microcontroller had to be given control over the fridge itself. This was achieved by programming it to activate a Kasa brand smart plug, which could switch mains power to the fridge as needed. The Uno simply emulated the action of the Kasa phone app to switch the smart plug on and off to control the fridge’s temperature, with the fridge essentially running flat out whenever it was switched on. The Uno also logs temperature to a server so [Rick] can make sure temperatures remain in the proper range.

We’ve seen some great beverage-cooling hacks over the years. If you’ve mastered your own hacky methods of keeping the colas chilled, don’t hesitate to let us know on the tipsline.

Build A Pocket-Sized Wi-Fi Analyzer

December 4, 2025 by 14 Comments

Wi-Fi! It’s everywhere, and yet you can’t really see it, by virtue of the technology relying on the transmission of electromagnetic waves outside the visual spectrum. Never mind, though, because you can always build yourself a Wi-Fi analyzer to get some insight into your radio surroundings, as demonstrated by [moononournation].

The core of the build is the ESP32-C5. The popular microcontroller is well-equipped for this task with its onboard dual-band Wi-Fi hardware, even if the stock antenna on most devboards is a little underwhelming. [moononournation] has paired this with a small rectangular LCD screen running the ILI9341 controller. The graphical interface is drawn with the aid of the Arduino_GFX library. It shows a graph of access points detected in the immediate area, as well as which channels they’re using and their apparent signal strength.

If you’re just trying to get a basic read on the Wi-Fi environment in a given locale, a tool like this can prove pretty useful. If your desires are more advanced, you might leap up to tinkering in the world of software defined radio. Video after the break.

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