Day: August 1, 2025

A Proper Computer For A Dollar?

August 1, 2025 by 49 Comments

When a tipster came to us with the line “One dollar BASIC computer”, it intrigued us enough to have a good look at [Stan6314]’s TinyBasRV computer. It’s a small PCB that forms a computer running BASIC. Not simply a microcontroller with a serial header, this machine is a fully functioning BASIC desktop computer that takes a PS/2 keyboard and a VGA monitor. Would that cheap price stand up?

The board uses a CH32 microcontroller, a RISC-V part that’s certainly very cheap indeed and pretty powerful, paired with an I2C memory chip for storage. The software is TinyBASIC. There’s some GPIO expandability and an I2C bus, and it’s claimed it can run in headless mode for a BASIC program to control things.

We haven’t added up all the parts in the BoM to check, but even if it’s not a one dollar computer it must come pretty close. We can see it could make a fun project for anyone. It’s certainly not the only small BASIC board out there, it’s got some competition.

Thanks [Metan] for the tip.

This Week In Security: Spilling Tea, Rooting AIs, And Accusing Of Backdoors

August 1, 2025 by 4 Comments

The Tea app has had a rough week. It’s not an unfamiliar story: Unsecured Firebase databases were left exposed to the Internet without any authentication. What makes this story particularly troubling is the nature of the app, and the resulting data that was spilled.

Tea is a “dating safety” application strictly for women. To enforce this, creating an account requires an ID verification process where prospective users share their government issued photo IDs with the platform. And that brings us to the first Firebase leak. 59 GB of photo IDs and other photos for a large subset of users. This was not the only problem.

There was a second database discovered, and this one contains private messages between users. As one might imagine, given the topic matter of the app, many of these DMs contain sensitive details. This may not have been an unsecured Firebase database, but a separate problem where any API key could access any DM from any user.

This is the sort of security failing that is difficult for a company to recover from. And while it should be a lesson to users, not to trust their sensitive messages to closed-source apps with questionable security guarantees, history suggests that few will learn the lesson, and we’ll be covering yet another train-wreck of similar magnitude in another few months.

Continue reading “This Week In Security: Spilling Tea, Rooting AIs, And Accusing Of Backdoors” →

A filament extruder is shown on a workbench. On the front is a knob and the display of a PID controller. A black geared spool is mounted on the top of the extruder, and on the right, a clear plastic bottle is positioned over a metal rod.

Turning Waste Plastic Into Spools Of Filament

August 1, 2025 by 28 Comments

Despite being a readily-available source of useful plastic, massive numbers of disposable bottles go to waste every day. To remedy this problem (or take advantage of this situation, depending on your perspective) [Igor Tylman] created the PETmachine, an extruder to make 3D printer filament from PET plastic bottles.

The design of the extruder is fairly standard for such machines: a knife mounted to the frame slices the bottle into one long strip, which feeds through a heated extruder onto a spool which pulls the plastic strand through the system. This design stands out, though, in its documentation and ease of assembly. The detailed assembly guides, diagrams, and the lack of crimped or soldered connections all make it evident that this was designed to be built in a classroom. The filament produced is of respectable quality: 1.75 mm diameter, usually within a tolerance of 0.05 mm, as long as the extruder’s temperature and the spool’s speed were properly calibrated. However, printing with the filament does require an all-metal hotend capable of 270 ℃, and a dual-drive extruder is recommended.

One issue with the extruder is that each bottle only produces a short strand of filament, which isn’t sufficient for printing larger objects. Thus, [Igor] also created a filament welder and a spooling machine. The welder uses an induction coil to heat up a steel tube, inside of which the ends of the filament sections are pressed together to create a bond. The filament winder, for its part, can wind with adjustable speed and tension, and uses a moving guide to distribute the filament evenly across the spool, avoiding tangles.

If you’re interested in this kind of extruder, we’ve covered a number of similar designs in the past. The variety of filament welders, however, is a bit more limited.

Thanks to [RomanMal] for the tip!

DIY MP3 Player Inspired By The IPod

August 1, 2025 by 6 Comments

These days, the personal MP3 player has been largely replaced by the the smartphone. However, [Justinas Petkauskas] still appreciates the iPod for its tactility and portability, and wanted to bring that vibe back. Enter JPL.mp3

The build is based around the ESP32-S3 microcontroller. It’s hooked up with a PCM5102 DAC hooked up over I2S to provide quality audio, along with a micro SD card interface for music storage, and a small IPS LCD. The best feature, though? The mechanical click-wheel which provides a very tactile way to scroll and interact with the user interface. Everything is assembled into a neat 3D printed case, with a custom four-layer PCB lacing all the electronics together.

On the software side, [Justinas] cooked up some custom software for organizing music on the device using a SQLite database. As he primarily listens to classical music, the software features fields for composer/piece and conductor, orchestra, or performer.

[Justinas] calls the final build “chunky, but nevertheless functional” and notes it is “vaguely reminiscent of classic iPods.” We can definitely see the fun in building your own personalized version of a much-enjoyed commercial product, for sure. Meanwhile, if you’re cooking up your own similar hardware, we’d certainly love to hear about it.