Misc Hacks

4182 Articles

Micro:Bit Gets Pseudo-Polyphonic Sound With Neat Hack

November 18, 2025 by No comments

The Micro:bit is a fun microcontroller development platform, designed specifically for educational use. Out of the box, it’s got a pretty basic sound output feature that can play a single note at a time. However, if you’re willing to get a bit tricky, you can do some pseudo-polyphonic stuff as [microbit-noob] explains.

The trick to polyphony in a monophonic world? Rapidly alternating between the different notes you want to be playing at the same time. Do this fast enough and it feels like they’re playing together rather than seperately. [microbit-noob] demonstrates how to implement this with a simple function coded for the Micro:bit. Otherwise, it uses the completely stock sound hardware. However, the IR receiver is added to the device in order to allow a simple remote control to be used to command the notes desired, along with some extra tactile buttons to add further control.

Is it chiptune? Well, it’s a chip, playing a tune, so yes. Even if it is through a tiny speaker stuck to the PCB. In any case, if you’re trying to get some better bleeps and bloops out of the Micro:bit, this is a great place to start. If you’ve got other hacks for Britain’s educational little board, let us know on the tipsline!

Building A Smart Speaker Outside The Corporate Cloud

November 17, 2025 by 12 Comments

If you’re not worried about corporate surveillance bots scraping your shopping list and manipulating you through marketing, you can buy any number of off-the-shelf smart speakers for your home. Alternatively, you can roll your own like [arpy8] did, and keep your life a little more private.

The build is based around an ESP32 microcontroller. It connects to the ‘net via its inbuilt Wi-Fi connection, and listens out for your voice with an INMP441 omnidirectional microphone module. The audio data is trucked off to a backend server running a Whisper speech-to-text model. The text is then passed to Google’s Gemini 2.5 Flash large language model. The response generated is passed to the Piper Neural Voice text-to-speech engine, sent back to the ESP32, and spat out via the device’s DAC output and a speaker attached to an LM386 amplifier. Basically, anything you could ask Gemini, you can do with this device.

By virtue of using a commercial large language model, it’s not perfectly private by any means. Still, it’s at least a little farther removed than using a smart speaker that’s directly logged in to your Amazon/Google/Hulu/Beanstikk account. Files are on Github for those eager to dive into the code. We’ve seen some other fun builds along these lines before, too. Video after the break.

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What Do You Call An Ekranoplan With An Outboard Motor?

November 13, 2025 by 5 Comments

If there’s one thing [rctestflight] likes, it’s… probably radio controlled test flights. If there are two things [rctestflights] likes, the second one is probably ground-effect vehicles, AKA Ekranoplans. Tired of having them flip over and crash, he’s trying an an innovative solution: stick a planing hull on it.

Ekranoplans have a stability problem because the center-of-pressure isn’t static: as the wing gets closer to the ground, the high pressure cushion of air that creates the ground effect tends to put more lift rearwards. The net effect of that is to torque the vehicle nose-down, which is kind of a self-limiting problem at a fraction of a wingspan’s altitude. The opposite problem is more concerning: the higher the ekranoplan gets, the more it wants to nose up, and there’s nothing to stop it. That leads to the vehicle flipping over. Continue reading “What Do You Call An Ekranoplan With An Outboard Motor?” →

Japan’s Forgotten Analog HDTV Standard Was Well Ahead Of Its Time

November 6, 2025 by 36 Comments

When we talk about HDTV, we’re typically talking about any one of a number of standards from when television made the paradigm switch from analog to digital transmission. At the dawn of the new millenium, high-definition TV was a step-change for the medium, perhaps the biggest leap forward since color transmissions began in the middle of the 20th century.

However, a higher-resolution television format did indeed exist well before the TV world went digital. Over in Japan, television engineers had developed an analog HD format that promised quality far beyond regular old NTSC and PAL transmissions. All this, decades before flat screens and digital TV were ever seen in consumer households!

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A Paintball Turret Controlled Via Xbox Controller

November 4, 2025 by 7 Comments

Video games, movies, and modern militaries are all full of robotic gun turrets that allow for remotely-controlled carnage. [Paul Junkin] decided to build his own, albeit in a less-destructive paint-hurling fashion.

The turret sits upon a lazy susan bearing mounted atop a aluminium extrusion frame. A large gear is mounted to the bearing allowing the turret to pan when driven by a stepper motor. A pair of pillow block bearings hold a horizontal shaft which mounts the two paint markers, which again is controlled by another stepper motor to move in the tilt axis. An ESP32 microcontroller is responsible for running the show, panning and tilting the platform by commanding the large stepper motors. Firing the paintball markers is achieved with solenoids mounted to the triggers, which cycle fast enough to make the semi-auto markers fire in a way that almost feels like full-auto. Commanding the turret is via an Xbox One controller; communicating with the ESP32 over Bluetooth using the BluePad32 library.

It’s worth noting you shouldn’t shoot paintballs at unsuspecting individuals, since they can do extreme amounts of damage to those not wearing the proper protection. We’ve featured a great many other sentry guns over the years, too, like this impressive Portal-themed build. Video after the break.

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An Audio Brick For Your Smart Home

November 1, 2025 by 38 Comments

If you’ve ever wanted to pump sound to all the rooms of your house, you might use any one of a number of commercial solutions. Or, you could go the more DIY route and whip up something like the Esparagus Audio Brick built by [Andriy]. 

The concept is simple—it’s a small unit, roughly the size of a brick, which streams high-quality audio. It’s based around an ESP32, which pulls in digital audio over Wi-Fi or Ethernet. The microcontroller is hooked up to a TAS5825M DAC, which comes with a built-in amplifier for convenience. The Esparagus is designed for integration with Home Assistant, allowing for easy control as part of a smart home setup. It’s also compatible with Spotify Connect, AirPlay, and Snapcast—the latter of which provides excellent sync when using multiple units across several rooms.

Design files are available on Github for the curious. We’ve seen other neat projects in this space, before, too—like the charmingly-named OtterCast. Video after the break.

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Building A Clamshell Writer Deck

October 31, 2025 by 10 Comments

Most of us do our writing on computers these days, but the modern computing environment does present a lot of distractions. That’s let to the concept of the writer deck, a simplified device intended more specifically for word processing tasks. [Ashtf] has built a great example of the form with a modified version of the PocketMage device.

The PocketMage is a clamshell PDA device that [Ashtf] has been working on for some time. It’s powered by an ESP32, hooked up to a nice e-ink display. In its basic form, it’s not the ideal device for doing serious writing work, mostly because of its tiny keyboard. However, [Ashtf] has since added external keyboard support, which completely changes the game. With the use of a small USB C to USB A adapter, you can hook up any conventional USB keyboard that you like to best attain your maximum typing speed.

The result is a compact, simple device that lets you type away without distractions. If your latest fanfic isn’t coming along quickly enough because you keep losing focus to social media, perhaps this is a route you might like to go. [Ashtf] also included Markdown support so you can create richer documents on the device while operating in what is still fundamentally a text-only environment.

It’s neat to build custom devices that suit your own personal productivity needs. If you dig the PocketMage, you might like to check out the design files on Github. We’ve featured some other fun writer decks before, too. Video after the break.

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