Splashflag: Raising The Flag On A Pool Party

October 5, 2025 by Matt Varian 7 Comments

Some things are more fun when there are more folks involved, and enjoying time in the pool is one of those activities. Knowing this, [Bert Wagner] started thinking of ways to best coordinate pool activities with his kids and their neighborhood friends. Out of this came the Splashflag, an IoT device built from the ground up that provides fun pool parties and a great learning experience along the way.

The USB-powered Splashflag is housed in a 3D-printed case, with a simple 2×16 LCD mounted on the front to display the notification. There’s also a small servo mounted to the rear that raises a 3D-printed flag when the notification comes in—drawing your attention to it a bit more than just text alone would. Hidden on the back is also a reset button: a long press factory-resets the device to connect to a different Wi-Fi network, and a quick press clears the notification to return the device to its resting state.

Inside is an ESP32-S3 that drives the servo and display and connects to the Wi-Fi. The ESP32 is set up with a captive portal, easing the device’s connection to a wireless network. The ESP32, once connected, joins an MQTT broker hosted by [Bert Wagner], allowing easy sending of notifications via the web app he made to quickly and easily send out invitations.

Thanks, [Bert Wagner], for sharing the process of building this fun, unique IoT device—be sure to read all the details on his website or check out the code and design files available over on his GitHub. Check out some of our other IoT projects if this project has you interested in making your own.

Continue reading “Splashflag: Raising The Flag On A Pool Party” →

Hackaday Links: October 5, 2025

October 5, 2025 by Dan Maloney 15 Comments

What the Flock? It’s probably just some quirk of The Almighty Algorithm, but ever since we featured a story on Flock’s crime-fighting drones last week, we’ve been flooded with other stories about the company, some of which aren’t very flattering. The first thing that we were pushed was this handy interactive map of the company’s network of automatic license plate readers. We had no idea how extensive the network was, and while our location is relatively free from these devices, at least ones operated on behalf of state, county, or local law enforcement, we did learn to our dismay that our local Lowe’s saw fit to install three of these cameras on the entrances to their parking lot. Not wishing to have our coming and goings documented, we’ll be taking our home improvement dollars elsewhere for now.

Continue reading “Hackaday Links: October 5, 2025” →

Divining Air Quality With A Cheap Computer Vision Device

October 5, 2025 by Lewin Day 10 Comments

There are all kinds of air quality sensors on the market that rely on all kinds of electro-physical effects to detect gases or contaminants and report them back as a value. [lucascreator] has instead been investigating a method of determining air quality that is closer to divination than measurement—using computer vision and a trained AI model.

The system relies on an Unihiker K10—a microcontroller module based around the ESP32-S3 at heart. The chip is running a lightweight convolutional neural network (CNN) trained on 12,000 images of the sky. These images were sourced from a public dataset; they were taken in India and Nepal, and tagged with the relevant Air Quality Index at the time of capture. [lucascreator] used this data to train their model to look at an image taken with a camera attached to the ESP32 and estimate the air quality index based on what it has seen in that existing dataset.

It might sound like a spurious concept, but it does have some value. [lucascreator] cites studies where video data was used for low-cost air quality estimation—not as a replacement for proper measurement, but as an additional data point that could be sourced from existing surveillance infrastructure. Performance of such models has, in some cases, been remarkably accurate.

[lucascreator] is pragmatic about the limitations of their implementation of this concept, noting that their very compact model didn’t always perform the best in terms of determining actual air quality. The concept may have some value, but implementing it on an ESP32 isn’t so easy if you’re looking for supreme accuracy. We’ve featured some other great air quality projects before, though, if you’re looking for other ways to capture this information. Video after the break.

Continue reading “Divining Air Quality With A Cheap Computer Vision Device” →

Optimizing A QuickTake Image Decoder For The Apple II’s 6502

October 5, 2025 by Maya Posch 7 Comments

The idea of using the Apple II home computer for digital photography purposes may seem somewhat daft considering that this is not a purpose that they were ever designed for, yet this is the goal that [Colin Leroy-Mira] had, requiring some image decoder optimizations. That said, it’s less crazy than one might assume at first glance, considering that the Apple II was manufactured until 1993, while the Apple QuickTake digital cameras that [Colin] wanted to use for his nefarious purposes saw their first release in 1994.

These QuickTake cameras feature an astounding image resolution of up to 640×480, using 24-bit color. Using the official QuickTake software for Apple Macintosh System 7 through 9 the photographs in proprietary QTK format could be fetched for display and processing. Doing the same on an Apple II would obviously require a bit more work, not to mention adapting of the image to the limitations of the 8-bit Apple II compared to the Motorola 68K and PowerPC-based Macs that the QuickTake was designed to be used with.

Targeting the typical ~1 MHz 6502 CPU in an Apple II, the dcraw QTK decoder formed the basis for an initial decoder. Many memory and buffer optimizations later, an early conversion to monochrome and various other tweaks later – including a conversion to 6502 ASM for speed reasons – the decoder as it stands today manages to decode and render a QTK image in about a minute, compared to well over an hour previously.

Considering how anemic the Apple II is compared to even a budget Macintosh Classic II system, it’s amazing that displaying bitmap images works at all, though [Colin] reckons that more optimizations are possible.

Wearable Neon Necklaces Run On Battery Power

October 5, 2025 by Lewin Day 22 Comments

We typically think of neon signs as big commercial advertisements, hanging inside windows and lofted on tall signposts outside highway-adjacent businesses. [James Akers] has gone the other route with a fashionable build, creating little wearable neon necklaces that glow beautifully in just the same way.

Aiming for small scale, [James] began with 6 mm blue phosphor glass tube, which was formed to reference Pink Pony Club, one of Chappell Roan’s more popular songs. The glass was then filled with pure neon up to a relatively low pressure of just 8 torr. This was an intentional choice to create a more conductive lamp that would be easier to run off a battery supply. The use of pure neon also made the tubes easy to repair in the event they had a leak and needed a refill. A Midget Script gas tube power supply is used to drive the tiny tubes from DC power. In testing, the tubes draw just 0.78 amps at 11.8 volts. It’s not a light current draw, but for neon, it’s pretty good—and you could easily carry a battery pack to run it for an hour or three without issue.

If you’re not a glass blower, fear not—you can always make stuff that has a similar visual effect with some LEDs and creativity. Meanwhile, if you’ve got your own neon creations on the go—perhaps for Halloween?—don’t hesitate to light up the tipsline!

3D Printing A New Kind Of Skateboard That Is Ultimately Unsafe

October 5, 2025 by Lewin Day 12 Comments

Skateboards were organically developed in the 1940s and 1950s; 30 years would then pass before the ollie was developed, unlocking new realms for skaters dedicated to the artform. The advent of powerful batteries and motors would later make the electric skateboard a practical and (un?)fashionable method of transport in more recent years. Now, [Ivan Miranda] is pushing the cutting edge of skateboarding even further, with an entirely weird build of his own design.

The build was inspired by one-wheels, which [Ivan] considers fun but ultimately too dangerous. Most specifically, he fears crashing when the one-wheel is tilted beyond a critical angle at which the motor can restore it to a level heading. His concept was to thus create a two-wheeled board that is nonetheless controlled with the leaning interface of a one-wheel.

The frame is assembled from a combination of 3D-printed brackets and aluminium extrusion. The rider stands on a platform which rides on rollers on top of the frame, tilting it to control the drive direction of the board. Detecting the angle is handled by an Arduino Due with an MPU6050 IMU onboard. The microcontroller is then responsible for commanding the speed controller to move the board. Drive is from a brushless DC motor, hooked up to one of the wheels via a toothed belt. Power is courtesy of three power tool batteries.

Early testing showed the design to be a bit of a death trap. However, with refinement to the control system code and an improved battery setup, it became slightly more graceful to ride. [Ivan] notes that more tuning and refinement is needed to make the thing safer than a one-wheel, which was the original goal. We’ve seen some other great builds from [Ivan] before, too. Video after the break.

Continue reading “3D Printing A New Kind Of Skateboard That Is Ultimately Unsafe” →

Simple Counter Mechanism In An Asthma Inhaler

October 5, 2025 by Maya Posch 10 Comments

The counter wheel and white worm gear inside the counter. (Credit: Anthony Francis-Jones, YouTube)

Recently [Anthony Francis-Jones] decided to take a closer look at the inhaler that his son got prescribed for some mild breathing issues, specifically to teardown the mechanical counter on it. Commonly used with COPD conditions as well as asthma, these inhalers are designed to provide the person using it with an exact dose of medication that helps to relax the muscles of the airways. Considering the somewhat crucial nature of this in the case of extreme forms of COPD, the mechanical counter that existed on older versions of these inhalers is very helpful to know how many doses you have left.

Disassembling the inhaler is very easy, with the counter section easily extracted and further disassembled. The mechanism is both ingenious and simple, featuring the counter wheel that’s driven by a worm gear, itself engaged by a ratcheting mechanism that’s progressed every time the cylinder with the medication is pushed down against a metal spring.

After the counter wheel hits the 0 mark, a plastic tab prevents it from spinning any further, so that you know for certain that the medication has run out. In the video [Anthony] speculates that the newer, counter-less inhalers that they got with the latest prescription can perhaps be harvested for their medication cylinder to refill the old inhaler, followed by resetting the mechanical counter. Of course, this should absolutely not be taken as medical advice.

Continue reading “Simple Counter Mechanism In An Asthma Inhaler” →