Round AMOLED Badge Does All Kinds Of Cool Stuff

September 16, 2026 by Zoe Skyforest 1 Comment

[curisama] has put together a project simply entitled The Badge. It’s simple enough, being a little round screen that you wear. Only, it does a wide variety of rather interesting things.

The build is based on the Waveshare ESP32-S3-Touch-AMOLED-1.75C. It’s not a very fun part number, but it describes a device which combines a 466×466 round display with a milled aluminium case and an ESP32-S3 to drive everything.

[curisama] started building a custom firmware for the device, intending to use it as an air mouse. Soon enough it had a touchpad, too, a bunch of extra keys, as well as a clock and some games. It was given the ability to record audio too, up to 52 minutes in WAV format. From there, it also gained a rather fetching liquid simulation, with water sloshing around the round display with a little boat riding around on it. This took some optimization, with [curisama] pushing the animation from 3 FPS all the way up to 18 fps, making it much more fluid and satisfying to watch. There were other optimizations too, with [curisama] figuring out how enabling the CONFIG_PM_ENABLE flag and some other tweaks could push standby battery life from 11.9 to 19.6 hours. Not a bad gain at all.

If you need a handy yet unassuming round object to act as a human interface device and some other stuff besides, consider buying the Waveshare part and flashing it yourself. You can do so right from your browser. We’ve featured plenty of other interesting projects with Waveshare parts in recent years, too. The integrated-display-and-microcontroller market is booming for makers right now, and it’s one we’ll continue to follow with interest. If you’re doing innovative stuff in this space, be sure to notify the tipsline!

An Open Heart Rate Monitor

September 14, 2026 by Jenny List 8 Comments

If you spend any time near a gym, you may be familiar with Bluetooth heart rate monitors — a small pack of electronics mounted on a strap round the chest which can relay heart rate data to an external logger or display. We’re pleased to see [Milos Rasic]’s project then, an open-source version of one of those monitors.

The heart rate capture is done by an AD8232, while the Bluetooth part is handled by a Seeed Studio XAIO ESP32 board. Power is provided by a single 3.7 V cell, with a boost converter to push that up to 5 V. The design omits a charge controller to keep things simple, so figuring out how to top off the cell is left as an exercise — no pun intended — for the user. Software is loaded through the Arduino IDE, which raises the possibility that other ESP32 CPUs could be supported with a bit of modification. All in all it’s a surprisingly simple project, and while the manufactured version is cheap enough it’s still very much worth having one that’s open source.

If you’d like to know more about his quest to develop open medical devices, check out the talk [Milos] gave on the intricacies of blood pressure monitoring earlier this year at Hackaday Europe.

Continue reading “An Open Heart Rate Monitor” →

Lara Croft On A Microcontroller

September 10, 2026 by Zoe Skyforest 16 Comments

Once upon a time, you had to carefully budget your microcontroller’s resources if you wanted to do something as simple as flash a bunch of LEDs. These days, they’re powerful enough to humiliate the game consoles of yesteryear. [alexkid77] demonstrates this well, having the ESP32-P4 run Tomb Raider.

Now, [alexkid77] hasn’t gone so far as to create a PlayStation emulator on the ESP32 or anything quite like that. Instead, this is a port—and not of the original Tomb Raider release, either. [alexkid77] started with OpenLara—the classic game running in an open-source engine. With the ESP32-P4 having two cores running at 400 MHz each, there was plenty of processing power on tap to run the engine with a software renderer at 320×240, which is hardware scaled up to 1024×600 via the Pixel Processing Accelerator (PPA) built into the chip. There’s also stereo audio with an ES8311 codec hooked up, while input is via a USB HID keyboard.

It’s funny to think that it could actually be cheaper and quicker to get Tomb Raider running on an ESP32 and a cheap LCD display versus actually going out to buy a PlayStation and an original game disc. But that’s the way the cookie crumbles in 2026. At least you don’t have to play it on an S3 Verge. Continue reading “Lara Croft On A Microcontroller” →

Woodstove Assistant Keeps The Heat On Safely

August 30, 2026 by Bryan Cockfield 3 Comments

Those who have never lived in a cold climate might romanticize winters around a fire, keeping warm under blankets while snow gently falls outside. While it certainly can be a cozy experience, using a woodstove comes with a number of pitfalls, and when operated improperly can even cause house-destroying chimney fires. Modern stoves operated properly with properly dried wood make this possibility extremely remote, but it’s still worth keeping an eye on. Reddit user [nas886] built a system called Oru which takes a lot of the guesswork out using one of these pieces of heating equipment.

The real danger of a woodstove isn’t necessarily running the fire too hot, although that can be a problem, but running it too cold. Without full combustion of the wood, flammable creosote builds up on the inside of the chimney which eventually can combust. This system uses a probe placed in the stovepipe to monitor the temperature of the exhaust gasses. If it’s too low an ESP32 notifies [nas886] remotely with with a status LED inside a seperate custom-built walnut enclosure so that more wood can quickly be added or airflow increased to bring up the temperature, and in the case that the fire gets too hot the LED changes to a different color and the air can be closed off a bit.

Woodstoves themselves have quite a bit of variability in the size wood they can burn, the amount they can hold at once, their efficiency, and their thermal mass, so this could find utility for anyone from those with tiny stoves that have to be fed constantly to those trying to get all-night burns in massive units, all without having to constantly sit by the fire and monitor it. [nas886] found initial success selling a few of these custom units and plans to put it into further production as well, but the general idea is not too difficult to replicate for most of us here either.

Continue reading “Woodstove Assistant Keeps The Heat On Safely” →

Fat Tire Brakes Get Wireless Upgrade

August 29, 2026 by Bryan Cockfield 51 Comments

At first glance, wireless brakes seem like a recipe for disaster. For something as critical as braking, many bicyclists might prefer a physical connection to their method of safely controlling speed. But there are a number of surprising benefits of electronic or wireless braking systems. For one, they can enable systems like anti-lock braking systems and for another they can eliminate cabling or hydraulics on a bicycle. For these reasons, and just for the thrill of it, [Berm Peak] built a set of wireless brakes for his fat tire bicycle to test out the possibilities.

The system uses a set of ESP32 microcontrollers to handle inputs from the braking lever and outputs to the front and rear brakes, as well as a central control unit and display. The brakes themselves are controlled by actuators from car door locks, which when combined with the springs from the stock calipers work to apply a wide range of braking force to the wheels. These did take a bit of prototyping to get working right, by changing to higher quality calipers, increasing the angle of the actuator, and adding longer levers, but eventually a working braking system started to appear.

But replacing a hydraulic system with an electronic one isn’t where something like this shines. [Berm Peak] was able to add in a number of features impossible in traditional braking systems. Not only does this have an ABS system and the possibility to remotely slow down his children’s bikes when they’re riding, but there’s also a braking equalizer that allows the rider to control how much braking there is at certain positions of the brake lever, and another setting called “derp” which doesn’t engage the brakes at all until a certain threshold has passed. This might end up being the next big trend in mountain biking, unlike airless tires.

Continue reading “Fat Tire Brakes Get Wireless Upgrade” →

Building A Headless Game Boy Emulator

August 28, 2026 by Zoe Skyforest 6 Comments

[Artificial-Age] has built a rather unique way to play old Game Boy games. It’s an emulator, but it doesn’t work in quite the way you might think!

Since the Game Boy is a relatively simple 8-bit machine that runs at a leisurely 4 MHz or so, it is well within the capabilities of an ESP32 microcontroller to emulate. [Artificial-Age] got an ESP32-S3 and programmed it to do just that. However, there’s a twist—there is no screen hooked up to the microcontroller, nor any buttons. Instead, the board is accessed over a WiFi access point that it hosts itself.

One then opens a web browser, which streams the emulated video and audio from the console, while accepting button inputs from your keyboard or touchscreen, depending on the platform you’re viewing the web interface on. ROMs are stored on the ESP32’s flash storage, and can be uploaded via the web interface.

It’s an interesting setup, and one that perhaps doesn’t make obvious sense at first. After all, any modern smartphone can easily emulate a Game Boy, too. However, this setup makes it easy to share the emulator with other people, who can simply check out the WiFi AP and web interface without having to download or or install anything on their own device. We’ve featured some other fun emulation projects lately, too.

Continue reading “Building A Headless Game Boy Emulator” →

Eenk Provides EInk, ESP32 Powered Text Adventures

August 27, 2026 by Tyler August 19 Comments

There’s a niche genre of text adventure that’s halfway between a traditional novel and a videogame. Think Zork if it had an extra few novels worth of words of well-crafted story to go with the action. [t0mg] is a fan of such adventures, and also quite enjoys carrying around his palm-sized ESP32 powered Xteink e-ink reader, so decided to create a project to merge the two interests, called eeink.

The Xteink readers have gotten popular lately because their modest internals and size make them very affordable. Not to mention hackable, since they’re basically an ESP32-C3 e-ink dev board that comes with a nice case and battery. The X4 Pro notably comes with an ESP32-S3 which means a lot more RAM, but this project targets both that and the X3/X4 that use the C3 version. Using the C3 means working within some rather stringent limits, as Xteink didn’t spring for any PSRAM, so [t0mg] had less memory to work with than folks did in the 80s.

This project is specifically focused on adventures using the scripting language ink, and comes with its own IDE called eenky to roll your own choose your own adventure book. It’s all on GitHub under an MIT license, and if you want to see it in action there’s a demo video embedded below.

Speaking of Zork, it wasn’t just the first commercial text adventure; it brought some important technological innovations, too.

Continue reading “Eenk Provides EInk, ESP32 Powered Text Adventures” →