ESP32

623 Articles

Cute Face Tells You How Bad The Air Quality Is

February 13, 2025 by 3 Comments

You can use all kinds of numbers and rating systems to determine whether the air quality in a given room is good, bad, or somewhere in between. Or, like [Makestreme], you could go for a more human visual interface. He’s built a air quality monitor that conveys its information via facial expressions on a small screen.

Named Gus, the monitor is based around a Xiao ESP32-C3. It’s hooked up with the SeeedStudio Grove air quality sensor, which can pick up everything from carbon monoxide to a range of vaguely toxic and volatile gases. There’s also a THT22 sensor for measuring temperature and humidity. It’s all wrapped up in a cute 3D-printed robot housing that [Makestreme] created in Fusion 360. A small OLED display serves as Gus’s face.

The indications of poor air quality are simple and intuitive. As “Gus” detects poor air, his eyelids droop and he begins to look more gloomy. Of course, that doesn’t necessarily tell you what you should do to fix the air quality. If your issue is pollution from outside, you’ll probably want to shut windows or turn on an air purifier. On the other hand, if your issue is excess CO2, you’ll want to open a window and let fresh air in. It’s a limitation of this project that it can’t really detect particulates or CO2, but instead is limited to CO and volatiles instead. Still, it’s something that could be worked around with richer sensors a more expressive face. Some will simply prefer hard numbers, though, whatever the case. To that end, you can tap Gus’s head to get more direct information from what the sensors are seeing.

We’ve seen some other great air quality projects before, too, with remarkably similar ideas behind them. Video after the break.

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Automatic Pill Dispenser Is Cheap And Convenient

February 12, 2025 by 20 Comments

If you’re taking any medication, you probably need to take it in a certain dose on a certain schedule. It can quickly become difficult to keep track of when you’re taking multiple medications. To that end, [Mellow_Labs] built an automated pill dispenser to deliver the right pills on time, every time.

The pill dispenser is constructed out of 3D printed components. As shown, it has two main bins for handling two types of pills, controlled with N20 gear motors. The bins spin until a pill drops through a slot into the bottom of the unit, with the drop detected by a piezo sensor. It uses a Beetle ESP32 as the brains of the operation, which is hooked up with a DS1307 real-time clock to ensure it’s dosing out pills at the right time. It’s also wired up with a DRV8833 motor driver to allow it to run the gear motors. The DRV8833 can run up to four motors in unidirectional operation, so you can easily expand the pill dispenser up to four bins if so desired.

We particularly like how the pill dispenser is actually controlled — [Mellow_Labs] used the ESP32 to host a simple web interface which is used for setting the schedule on which each type of pill should be dispensed.

We’ve featured some other pill dispenser builds before, too.

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Push Your Toy Train No More, With This Locomotive!

February 11, 2025 by 8 Comments

One of the most popular evergreen toys is also one of the simplest, wooden track with push-along trains. We all know the brand name, and savvy parents know to pick up the much cheaper knock-off because the kid won’t know the difference. But a really cool kid shouldn’t have to push their train around by hand, and thus [Lauri] has given the wooden track a real, powered, locomotive.

In the 3D printed chassis goes a small geared motor driving one axle, with an ESP32 and a motor driver taking care of the smarts. Power comes from an 18650 cell, which almost looks like the right scale for a fake steam boiler. The surprise with this train comes in the front axle, this machine has steering. We’re curious, because isn’t the whole point of a train that the track directs it where it needs to go? Or perhaps a little help is required in the absence of a child’s guidance when it comes to points. Either way, with remote control we guess there would be few kids who wouldn’t want one. We certainly do.

A Tiny Computer With A 3D Printed QWERTY Keyboard

February 11, 2025 by 10 Comments

The ESP32 family are the microcontrollers which just keep on giving, as new versions keep them up-to-date and plenty of hackers come up with new things for them. A popular device is a general purpose computer with a QWERTY keypad, and the latest of many we’ve seen comes from [StabbyJack]. It’s a credit card sized machine whose special trick is that its keyboard is integrated in the 3D printing of its case. We’ve seen rubber membranes and push in keys, but this one has flexible print-in-place keys that line up on the switches on its PCB.

It’s not complete yet but the hardware appears to be pretty much there, and aside from that keyboard it has an ESP32-S3 and a 1.9″ SPI LCD. When finished it aims for an ambitious specification, with thermal camera and time-of-flight range finder hardware, along with an OS and software to suit. We like it a lot, though we suspect it might be a little small for our fingers.

If you like this project you may appreciate another similar one, and perhaps your version will need an OS.

DIY Drones Deliver The Goods With Printed Release

January 22, 2025 by 17 Comments

It seems like the widespread use of delivery drones by companies like Amazon and Wal-Mart has been perpetually just out of reach. Of course robotics is a tricky field, and producing a fleet of these machines reliable enough to be cost effective has proven to be quite a challenge. But on an individual level, turning any drone into one that can deliver a package is not only doable but is something [Iloke-Alusala] demonstrates with their latest project.

The project aims to be able to turn any drone into a delivery drone, in this case using a FPV drone as the platform. Two hitch-like parts are 3D printed, one which adds an attachment point to the drone and another which attaches to the package, allowing the drone to easily pick up the package and then drop it off quickly. The real key to this build is the control mechanism. [Iloke-Alusala] used an ESP32 to tap into the communications between the receiver and the flight controller. When the ESP32 detects a specific signal has been sent to the flight controller, it can activate the mechanism on the 3D printed hitch to either grab on to a package or release it at a certain point.

While this is a long way from a fully autonomous fleet of delivery drones, it goes a long way into showing that individuals can use existing drones to transport useful amounts of material and also sets up a way for an ESP32 to decode and use a common protocol used in drones, making it easy to expand their capabilities in other ways as well. After all, if we have search and rescue drones we could also have drones that deliver help to those stranded.

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Photo of 3D Tetris LED matrix

From Retro To Radiant: 3D Tetris On A LED Matrix

January 21, 2025 by 8 Comments

We love seeing retro games evolve into new, unexpected dimensions. Enter [Markus]’ adaptation of 3D Tetris on a custom-built 3x3x12 RGB LED matrix. Developed as a university project, this open-source setup combines coding, soldering, and 3D printing. It’s powered by an ESP32 microcontroller with gameplay controlled by a neat web interface.

This 3D build makes the classic game so much harder to play, that one could argue whether it’s still a game, or has turned into a form of art. Although it is challenging to rotate and drop blocks on such a small scale, for die-hard Tetris fans (and we know you’re out there), there is always someone up to become best at it. Just look at the FastLED-powered light show, the responsive web-based GUI, and fully modular 3D printed housing, this project is a joy to look at even when nobody is playing it. Heck, a game that turned 40 only a year ago should be so mature to entertain itself, shouldn’t it?

From homemade Pong tables to LED cube displays, hobbyists keep finding ways to give classic games a futuristic twist. Projects like this are about pushing boundaries. Hackaday’s archives are full of similar innovations, but why not craft some new ones?

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desk with circuit schema and AirTag

Stealth AirTag Broadcasts When Moved: An Experiment

January 18, 2025 by 43 Comments

A simple yet intriguing idea is worth sharing, even if it wasn’t a flawless success: it can inspire others. [Richard]’s experiment with a motion-powered AirTag fits this bill. Starting with our call for simple projects, [Richard] came up with a circuit that selectively powers an AirTag based on movement. His concept was to use an inertial measurement unit (IMU) and a microcontroller to switch the AirTag on only when it’s on the move, creating a stealthy and battery-efficient tracker.

The setup is minimal: an ESP32 microcontroller, an MPU-6050 IMU, a transistor, and some breadboard magic. [Richard] demonstrates the concept using a clone AirTag due to concerns about soldering leads onto a genuine one. The breadboard-powered clone chirps to life when movement is detected, but that’s where challenges arise. For one, Apple AirTags are notoriously picky about batteries—a lesson learned when Duracell’s bitter coating blocks functionality. And while the prototype works initially, an unfortunate soldering mishap sadly sends the experiment off the rails.

Despite the setbacks, this project may spark a discussion on the possibilities of DIY digital camouflage for Bluetooth trackers. By powering up only when needed, such a device avoids constant broadcasting, making it harder to detect or block. Whether for tracking stolen vehicles or low-profile uses, it’s a concept rich with potential. We talked about this back in 2022, and there’s an interesting 38C3 talk that sheds quite some light on the broadcasting protocols and standards. Continue reading “Stealth AirTag Broadcasts When Moved: An Experiment” →