Building A Big RC Mini Truck

April 16, 2026 by Zoe Skyforest 3 Comments

Kei trucks are some of the smallest commercial vehicles out on the roads today. You can also get lots of cute kei RC cars if you’re into the toy side of things. [Victor] wanted to split the difference with Truck-Kun, and built a 1:3 scale kei truck to show off at a recent anime convention.

The truck is modelled on the Suzuki Carry.

The build started with a classic hacker favorite—a bunch of old hoverboard motors. These brushless hub motors are pretty easy to drive and have plenty of torque right out of the box. A simple ladder frame was whipped up with a hoverboard wheel at each corner, with a body whipped up out of cardboard, paint, and a few 3D printed parts to hold everything together.

Steering was courtesy of a leadscrew and stepper motor from an old 3D printer. RP2040s were thrown in to talk to the motor controllers, while an ESP32-S3 was charged with communicating with an Xbox One controller to receive directional commands.

It was a neat build that stood tall over most any other kei RC car at Anime Los Angeles. Only, it ended in tears when the 100-pound machine accidentally drove at full throttle into a wall and smashed itself to pieces. Still, that’s just an excuse for [Victor] to build a better one for next year.

We love a good RC build around these parts, and we love kei trucks too.

Rust-y Firmware For Waveshare Smartwatch

April 11, 2026 by Tyler August 2 Comments

Waveshare makes a nifty little ESP32-S3 based smartwatch product, but its firmware is apparently not to everyone’s liking. Specifically, it’s not to [infiniton] a.k.a [Bright_Warning_8406]’s liking, as they rewrote the entire code base in Rust. No_std Rust, to be specific, but perhaps that doesn’t need to be specified when dealing with ESP32.

On the Reddit thread about the project, he lists some of the advantages. For one thing, the size of the binary has dropped from 1.2 MB to 579 kB while maintaining the same functionality. More interesting is that he’s been able to eliminate polling entirely: the firmware is purely event-driven. The CPU is not just idle but parked until a timer or GPIO event wakes it up. For this form factor, that’s a big deal — you can’t fit a very large battery in a watch, after all.

Getting drivers for the AMOLED display, touch sensor, audio, and RTC modules written from scratch is an impressive accomplishment. Apparently the screen driver in particular was “a nightmare” and we believe it. There’s a reason most people go for existing libraries for this stuff. [Bright_Warning] did not post screenshots or video, but claims his version of the watch watch can make HTTP calls to Smart Home, play MP3s, play the old phone games– Snake, 2048, Tetris, Flappy Bird, Maze– and even comes with a T9 keyboard for text input.

If you’re looking to get closer to bare metal, and don’t mind it being Rust-y, take a look at the code on GitHub in the first link above. This author isn’t enough of a rustacean to say if the code is as good as it sounds at a glance, but nothing egregious jumps out. The documentation describing exactly what’s going on under the hood isn’t half-bad, either. If you aren’t into Waveshare products, you could easily adapt this code into a more DIY ESP32 watch, too.

If you’re not into Rust, uh… washing soda and electric current can get it off of steel, and probably microcontrollers too. We can’t say that the chip will work after that, but hey — no rust.

Simulating The AVR8 For A Browser-based Arduino Emulator

April 6, 2026 by Fenix Guthrie 8 Comments

It’s always nice to simulate a project before soldering a board together. Tools like QUCS run locally and work quite well for analog circuits, but can fall short with programmable logic. Tools like Wokwi handle the programmable side quite well but may have license issues or require the cloud. The Velxio project by [David Montero Crespo] is quite an excellent example of an (online) circuit simulator with programmable logic and local execution!

It’s built largely around Wowki’s AVR8JS library for Arduino simulation. All CPU simulation occurs on the local computer, while sketch compilation happens on the backend using official Arduino tools. But this was certainly not the most impressive aspect of the project. Likewise, Velxio features RP2040 execution using the rp2040js library. It also features the execution of some ESP32 derivative boards built around the RISC-V architecture using the RiscVCore.ts library.

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Building A Monitor Light Bar For Better Productivity

March 24, 2026 by Zoe Skyforest 10 Comments

If you’re intending to work at your desk for long periods of time, good lighting is a must, as it can help stave off eye strain and mental fatigue. It was a desire for more comfortable productivity that drove [Jade] to whip up a monitor-mounted lighting system for her workstation.

The build uses an ESP32 to run the show, with a rotary encoder for manual control and firmware that allows the monitor light to be neatly integrated with Home Assistant. The light itself comes from light strips that feature both warm white and cold white LEDs. Simple MOSFETs are used to control the brightness of the LEDs and which of the warm and cold LEDs are activated at any time. Everything is wrapped up in a 3D printed housing that neatly sits on top of the monitor with the aid of a simple printed clamp. The LED strips also have a nice soft glow thanks to a strip of diffuser material that [Jade] snatched from an old television.

We love a good lighting build, from the work-focused to the creative and beautiful.

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Stream Deck Radio Controller Built With Cheap Yellow Display

March 23, 2026 by Zoe Skyforest 4 Comments

Stream decks are pretty useful in all kinds of contexts, but commercial models can feel a bit pricy for what is effectively a bunch of buttons. [WhiskeyTangoHotel] has whipped up one of their own on the cheap using some readily available parts.

The build came about due to the use of Stream Decks as a common way to control the Flex-6400 software-defined radio. [WhiskeyTangoHotel] figured that using a full-priced Elgato Stream Deck was overkill for this purpose, and that a cheaper interface could be put together for less. Enter the Cheap Yellow Display—a combination of the ESP32 microcontroller with a 2.8-inch touchscreen LCD. It was simple enough to code the device such that it had four big touch buttons to control RIT-, RIT+, XIT-, and XIT+ on the Flex-6400. Plus, with the ESP32 having WiFi onboard, it’s able to control the radio wirelessly—you just need to feed the unit 5 volts, and you’re up and running.

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Better Faux-Analog VU Meters

March 23, 2026 by Zoe Skyforest 5 Comments

One of the coolest things about old hi-fi hardware is that it often came with flickety needles that danced with the audio level. You can still buy these if you want, or you can simulate the same look on a screen, as [mircemk] demonstrates.

It isn’t [mircemk]’s first rodeo in this regard. An earlier project involved creating simulated VU meters on round displays, but they were somewhat limited. Using the Adafruit GFX library on an ESP32 netted a working setup, but it was jerky and very jagged and digital-looking. It was more akin to a fake needle display running on an 8-bit computer than something that looked like a real vintage VU meter.

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3D Printed Clock Just Taps It In

March 21, 2026 by Bryan Cockfield 4 Comments

The famous cuckoo clock, with its moving, chirping mechanical bird indicating various divisions of time, has been around since at least the 1600s. The most famous of them come from the Black Forest area of Germany, and are still being made worldwide even today. Other clocks with different themes take their inspiration from the standard bird-based clocks from history, and thanks to modern 3D printing and other technologies we can make clocks with almost any type of hour indicator we’d like with relative ease like [Jason]’s golf clock.

While the timekeeping mechanism is a fairly standard analog clock, the hour indicator mechanism in this build is a small figure which putts a golf ball into a hole once every hour. It uses an ESP32-C3 at its core, which controls a pair of servos. One controls the miniature golfer, and the other lifts the ball up into position on the green at the appointed time. Once the ball is in place, the figure rotates, striking the ball towards the hole. Although it looks almost like the ball is guided by a magnet of some sort at first glance, the ball naturally finds its way into the hole by the topography of the green alone.

Almost all of the parts in this build are 3D printed, including the green, the golfer, the frame, and a number of the servo components. There’s also a small sensor that detects if the ball has actually made it into the hole and back to the lifting mechanism, and to that end there’s also a number of configurations that can be made in the software to ensure that the servos controlling everything all work together to putt the ball properly.

While not a cuckoo clock in the strict sense, we always appreciate a unique clock around here, but if you demand your clocks have ideological purity we’ll point you to this cuckoo clock built into a wristwatch.

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