Possibly-Smallest ESP32 Board Uses Smallest-Footprint Parts

November 19, 2025 by No comments

Whenever there’s a superlative involved, you know that degree of optimization has to leave something else on the table. In the case of [PegorK]’s f32, the smallest ESP32 dev board we’ve seen, the cost of miniaturization is GPIO.

There’s only one GPIO pin broken out, and it’s pre-wired to an LED. That’s the bad news, and depending on what you want an ESP32 for, it might not phase you at all. What is impressive here, if not the number of I/O pins, is the size of the board: at 9.85 mm x 8.45 mm barely overhangs the USB-C socket that takes up one side of the board.

Pegor provides this helpful image in the readme so you know what you’re getting into with the 01005 resistors.

In order to get the ESP32-C3FH4 onto such a tiny board, all of the other support hardware had to be the smallest possible sizes– including resistors in 01005. If you don’t speak SMD, one could read that number code as “oh god too small” — at 0.4 mm x 0.2 mm it’s as minuscule as you’ll find– and [Pegor] hand soldered them.

OK, he did use a hot plate for the final step, but he did tin the pads manually with a soldering iron, which is still impressive. Most of us probably would have taken PCBWay up on their offer of assembly services, but not [Pegor]. Apparently part of the reason for this project was that he was looking for an excuse to use the really small footprint components.

Aside from leaving out GPIO and needing too-small SMD components, [Pegor] admits that pesky little details like antenna matching circuits and decoupling capacitors had to get cut to make the tiny footprint, so this board might be more of a stunt than anything practical. So what can you do with the smallest ESP32 board? Well, [Pegor] put up a basic web interface up to get you started blinking the built-in LED; after that, it’s up to you. Perhaps you might fancy a teeny-tiny minecraft server? If you can stand to increase the volume a little bit, we’ve seen how to hack a C3 for much better wifi performance.

Thanks to [Pegor] for the tip, and remember– submit your projects, big or small, we read ’em all!

Build A Stranger Things Wall You Can Freak Out At In Your Own Home

November 19, 2025 by No comments

When Stranger Things premiered in 2016, it was a cultural force. Foreign DJs gushed over the lush 80s soundtrack, fashionistas loved the clothing, and the world became obsessed with the idea of using Christmas lights to communicate across material planes. [kyjohnso] has recreated that experience with the technology of today.

If you haven’t watched the show — Joyce Byers is trying to communicate with her son Will, who just so happens to be stuck in another plane of existence called the Upside Down. She screams questions at her living room wall, upon which hangs a series of Christmas lights, marked with the letters A to Z. Will is able to communicate back by causing the lights to flash, one letter at a time.

This build works a little differently. You basically type a message into a terminal on a Raspberry Pi, and it gets sent to a large language model—namely, the Claude API. The response from Claude (or Will Byers, if you’re imagining) is then flashed out on a WS2812B set of LED Christmas lights on the wall. [kyjohnso] added dramatic pauses whenever there’s a space in the output, somewhat replicating the dramatic elements of the show itself. Files are on GitHub for the spooky and curious.

It’s a neat build that would be a hit at any Halloween party. We can’t imagine how much more immersive it would be if paired with a speech-to-text engine so you could actually scream at the thing like a distraught Midwestern parent who has just lost her youngest child. It’s all about committing to the bit; if you build such a thing, don’t hesitate to notify the tipsline!

FLOSS Weekly Episode 855: Get In The Minecart, Loser!

November 19, 2025 by No comments

This week Jonathan chats with Kevin, Colin, and Curtis about Cataclysm: Dark Days Ahead! It’s a rogue-like post-apocalyptic survival game that you can play in the terminal, over SSH if you really want to! Part of the story is a Kickstarter that resulted in a graphics tile-set. And then there’s the mods!

Continue reading “FLOSS Weekly Episode 855: Get In The Minecart, Loser!” →

Hackers Can’t Spend A Penny

November 19, 2025 by 36 Comments

We aren’t here to praise the penny, but rather, to bury it. The penny, and its counterparts, have been vanishing all around the world as the cost of minting one far outweighs its value. But hackers had already lost a big asset: real copper pennies, and now even the cheaply made ones are doomed to extinction.

If you check your pockets and find a pre-1982 penny, it’s almost all copper. Well, 95% of its slightly-more-than-3-gram heft is pure copper. Since then, the copper penny’s been a fraud, weighing 2.5 g and containing only a 2.5% copper plate over a zinc core. During WWII, they did make some oddball steel pennies, but that was just a temporary measure.

Continue reading “Hackers Can’t Spend A Penny” →

Damn Fine (Solar Powered) Coffee

November 19, 2025 by 19 Comments

The folks at Low Tech Magazine are here again, this time with a solar powered coffee maker. Lest you think of a large parabolic mirror with a pot at its focus, in this case the device is much more friendly. It’s a table-top appliance that relies upon a 100 W 12 V panel for its operation.

They make the point that an electric coffee pot requires at least 300 W to work, so what’s the secret? In this case, insulation, as a standard moka pot is placed within a nichrome heating element set in mortar and surrounded by cork. On the outside are tiles, though they appear largely ornamental and the write-up suggests you could experiment with other materials to serve as an enclosure.

It appears to be an effective coffee maker, with the significant caveat that it’s hardly fast. In full sunlight the first pot takes over an hour to brew, with subsequent ones once it’s up to temperature being somewhat faster. But you can’t argue with the idea of free power, even if your favourite caffeinated beverage may now take a while to appear.

We like this idea, despite its slow brewing. We’ve featured Low Tech Magazine before, not least in their solar powered oven.

Why Samsung Phones Are Failing Emergency Calls In Australia

November 19, 2025 by 39 Comments

We’re taught how to call emergency numbers from a young age; whether it be 911 in the US, 999 in the UK, or 000 in Australia. The concept is simple—if you need aid from police, fire, or ambulance, you pick up a phone and dial and help will be sent in short order.

It’s a service many of us have come to rely on; indeed, it’s function can swing the very balance between life or death. Sadly, in Australia, that has come to pass, with a person dying when their Samsung phone failed to reach the Triple Zero (000) emergency line. It has laid bare an obscure technical issue that potentially leaves thousands of lives at risk. Continue reading “Why Samsung Phones Are Failing Emergency Calls In Australia” →

Smart Bandage Leverages AI Model For Healing Purposes

November 19, 2025 by 11 Comments

If you get a small cut, you might throw a plastic bandage on it to help it heal faster. However, there are fancier options on the horizon, like this advanced AI-powered smart bandage.

Researchers at UC Santa Cruz have developed a proof-of-concept device called a-Heal, intended for use inside existing commercial bandages for colostomy use. The device is fitted with a small camera, which images the wound site every two hours. The images are then uploaded via a wireless connection, and processed with a machine learning model that has been trained to make suggestions on how to better stimulate the healing process based on the image input. The device can then follow these recommendations, either using electrical stimulation to reduce inflammation in the wound, or supplying fluoxetine to stimulate the growth of healthy tissue. In testing, the device was able to improve the rate of skin coverage over an existing wound compared to a control.

The long-term goal is to apply the technology in a broader sense to help better treat things like chronic or infected wounds that may have difficulty healing. It’s still at an early stage for now, but it could one day be routine for medical treatment to involve the use of small smart devices to gain a better rolling insight on the treatment of wounds. It’s not the first time we’ve explored innovative methods of wound care; we’ve previously looked at how treatments from the past could better inform how we treat in future.