ESP32 Decodes S/PDIF Like A Boss (Or Any Regular Piece Of Hi-Fi Equipment)

October 6, 2025 by 5 Comments

S/PDIF has been around for a long time; it’s still a really great way to send streams of digital audio from device A to device B. [Nathan Ladwig] has got the ESP32 decoding SPDIF quite effectively, using an onboard peripheral outside its traditional remit.

On the ESP32, the Remote Control Transceiver (RMT) peripheral was intended for use with infrared transceivers—think TV remotes and the like. However, this peripheral is actually quite flexible, and can be used for sending and receiving a range of different signals. [Nathan] was able to get it to work with S/PDIF quite effectively. Notably, it has no defined bitrate, which allows it to work with signals of different sample rates quite easily. Instead, it uses biphase mark code to send data. With one or two transitions for each transmitted bit, it’s possible to capture the timing and determine the correct clock from the signal itself.

[Nathan] achieved this feat as part of his work to create an ESP32-based RTP streaming device. The project allows an ESP32 to work as a USB audio device or take an S/PDIF signal as input, and then transmitting that audio stream over RTP to a receiver which delivers the audio at the other end via USB audio or as an SPDIF output. It’s a nifty project that has applications for anyone that regularly finds themselves needing to get digital audio from once place to another. It can also run a simple visualizer, too, with some attached LEDs.

It’s not the first time we’ve seen S/PDIF decoded on a microcontroller; it’s quite achievable if you know what you’re doing. Meanwhile, if you’re cooking up your own digital audio hacks, we’d love to hear about it. Digitally, of course, because we don’t accept analog phone calls here at Hackaday. Video after the break.

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Apple’s Continuing Failing Repair Score With The AirPods Pro 3

October 5, 2025 by 18 Comments

It takes quite a bit of effort to get a 0 out of 10 repairability score from iFixit, but in-ears like Apple’s AirPods are well on course for a clean streak there, with the AirPod Pro 3 making an abysmal showing in their vitriolic teardown video alongside their summary article. The conclusion is that while they are really well-engineered devices with a good feature set, the moment the battery wears out it is effectively e-waste. The inability to open them without causing at least some level of cosmetic damage is bad, and that’s before trying to glue the device back together. Never mind effecting any repairs beyond this.

Worse is that this glued-together nightmare continues with the charging case. Although you’d expect to be able to disassemble this case for a battery swap, it too is glued shut to the point where a non-destructive entry is basically impossible. As iFixit rightfully points out, there are plenty of examples of how to do it better, like the Fairbuds in-ears. We have seen other in-ears in the past that can have some maintenance performed without having to resort to violence, which makes Apple’s decisions here seem to be on purpose.

Although in the comments to the video there seem to be plenty of happy AirPod users for whom the expected 2-3 year lifespan is no objection, it’s clear that the AirPods are still getting zero love from the iFixit folk.

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Splashflag: Raising The Flag On A Pool Party

October 5, 2025 by 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.

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Hackaday Links: October 5, 2025

October 5, 2025 by 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.

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Divining Air Quality With A Cheap Computer Vision Device

October 5, 2025 by 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.

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

October 5, 2025 by 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 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!