Review: Beepy, A Palm-sized Linux Hacking Playground

In the long ago times, when phones still flipped and modems sang proudly the songs of their people, I sent away for a set of Slackware CDs and embarked on a most remarkable journey. Back then, running Linux (especially on the desktop) was not a task to be taken lightly. The kernel itself was still in considerable flux — instead of changing some obscure subsystem or adding support for a niche gadget you don’t even own, new releases were unlocking critical capabilities and whole categories of peripherals. I still remember deciding if I wanted to play it safe and stick with my current kernel, or take a chance on compiling the latest version to check out this new “USB Mass Storage” thing everyone on the forums was talking about…

But modern desktop Linux has reached an incredible level of majority, and is now a viable choice for a great number of computer users. In fact, if you add Android and Chrome OS into the mix, there are millions and millions of people who are using Linux on daily basis and don’t even realize it. These days, the only way to experience that sense of adventure and wonderment that once came pre-loaded with a Linux box is to go out and seek it.

Which is precisely how it feels using using the Beepy from SQFMI. The handheld device, which was formerly known as the Beepberry before its creators received an all-too-predicable formal complaint, is unabashedly designed for Linux nerds. Over the last couple of weeks playing with this first-run hardware, I’ve been compiling kernel drivers, writing custom scripts, and trying (though not always successfully) to get new software installed on it. If you’re into hacking around on Linux, it’s an absolute blast.

There’s a good chance that you already know if the Beepy is for you or not, but if you’re still on the fence, hopefully this in-depth look at the hardware and current state of the overall project can help you decide before SQFMI officially starts taking new orders for the $79 gadget.

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A Magnetohydrodynamic Drive In The Kitchen Sink

The magnetohydrodynamic (MHD) drive certainly sounds like something out of science fiction — using an array of magnets and electrodes, this high-tech propulsion technology promises to silently propel a craft through the water without any moving parts. As long as you can provide it with a constant supply of electricity, anyway.

Of course, as is often the case, the devil is in the details. Even with the obvious scientific and military applications of such a propulsion unit, scaling MHD technology up has proven difficult. But as [Jay Bowles] of Plasma Channel shows in his latest video, that doesn’t mean you can’t experiment with the concept at home. Even better, getting verifiable results is much easier than you’d think.

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This Kinetic Art Display Uses A Gin Bottle

[David McDaid] likes gin. So in homage to their favourite tipple, a certain brand of Scottish origin, a kinetic art project was brewed. Tabled as a Rube Goldberg machine — it’s not — but it is a very smart marble run type installation, dripping with 3D printed parts and a sprinkling of blinkenlights.

The write-up shows the degree of pain we go through with building such contraptions, apparently [David] burned through 2.5 kg of PLA filament despite the bill of materials requiring a mere 660 g. Much experimentation, trial and error, and plenty of print-and-reprint-until-good-enough, resulted in a clean looking run with some neat features. We particularly like the use of a stainless steel jigger to add a touch of metallic ting, to the soundscape produced. The whole show was put together in Fusion 360, since all those tight tolerances do not make for a simple construction without a lot of fiddling around with the layout. Once it was a sound, layout was prototyped on a wood board, which was subsequently used a drill template for the final acrylic version.

On the electronics side of things, an Arduino Nano clone is on control duty, reading an IR trip sensor to fire of a simple light effect, illuminating the gin bottle in a slick fashion. These machines need a mechanism to raise the balls against that pesky force of gravity, in this instance a 3D printed custom chain was constructed, driven with a stepper motor in turn driven from a TMC2208. You see, this thing lives in the kitchen, so the aim was to keep all the noise from the mechanics to a minimum so only the noise of LDPE balls rattling around can be heard. They are the star of the show after all! The build looks nice and would certainly be something we’d like to see on the wall. Obviously we’ve seen a few marble runs over the years. Here’s an interesting one that uses an elevator mechanism, and another project that shows how to generate runs procedurally.

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An Open Firmware For LILYGO’s E-ink Smart Watch

The world’s first quartz wristwatches were miles ahead of electric and mechanical wristwatches by most standards of the time, their accuracy was unprecedented and the batteries typically lasted somewhere on the order of a year. Modern smart watches, at least in terms of battery life, have taken a step backwards — depending on use, some can require daily charging.

If you’re looking to bridge the gap between a day and a year, you might look into a smart watch with an e-ink display. One option is the ESP32-based LILYGO T-Wrist. Of course, it’s not a smart watch without some software to run on it, which is where qpaperOS comes in.

Developed by [qewer33], this open source firmware for the T-Wrist is designed to get the most out of the battery by updating only once per minute. With a 250 mAh battery, it should last about five days on a charge. Of course, with the power of the ESP32 comes a whole host of other features including GPS, a step counter, and a weather display, although since the firmware is still under development, some of these features have yet to be implemented.

With all of the code available, qpaperOS could make an excellent platform from which to build your own smart watch around. Or perhaps you could chip in and add some of the features on the whislity. The ESP32 is a capable and versatile chip, even capable of playing popular 8-bit video games, although we’re not sure this functionality would fit in a smart watch and preserve battery life at the same time.

Star Wars Pit Droid Has A Jetson Brain

In the Star Wars universe, pit droids are little foldable robots that perform automated repairs on spacecraft and the like. They were introduced in 1999’s The Phantom Menace, and beyond the podracing scenes, are probably the only good thing to come out of that particular film.

[Goran Vuksic] wanted a pit droid of his own, and reasoned that if he was going to go through the trouble of sanding and painting all the 3D printed components so they look like the real bot, he might as well add some smarts to it. While this droid won’t be fixing podracers anytime soon, its onboard Jetson Orin Nano Developer Kit does pack a considerable amount of processing under that dome.

A webcam mounted in the bot’s eye socket is connected to the Jetson, which is running an image detection and identification routine based on the example code provided by NVIDIA. The single-board computer uses a relay to blink some LEDs on and off when a human is detected, and a pair of servos pan-and-tilt the bot’s head towards whoever has caught its gaze.

It’s no surprise that [Goran] picked the Jetson Orin over competing SBCs for this task — in our review of the Orin Nano Developer Kit a few months ago, we found it was able to hit nearly 200 frames per second while performing this sort of real-time image analysis. So there’s plenty of room to grow should he want to integrate more complex image recognition tasks.

For example, he could follow in the footsteps of [Kris Kersey], and put a functional data overlay on top of the video to give his bot Iron Man vision.

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Hackaday Links: August 6, 2023

“Have you tried turning it off and on again?” is a common tech support maneuver that everyone already seems to know and apply to just about all the wonky tech in their life. But would you tell someone to apply it to a reservoir? Someone did, and with disastrous results, at least according to a report on the lead-up to the collapse of a reservoir in the city of Lewiston, Idaho — just across the Snake River from Clarkston, Washington; get it? According to the report, operators at the reservoir had an issue crop up that required a contractor to log into the SCADA (supervisory control and data acquisition) system running the reservoir. The contractor’s quick log-in resulted in him issuing instructions to local staff to unplug the network cable on the SCADA controller and plug it back in. Somehow, that caused a variable in the SCADA system — the one storing the level of water in the reservoir — to get stuck at the current value. This made it appear that the water level was too low, which lead the SCADA system to keep adding water to the reservoir, which eventually collapsed.

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Blinkenlights To Bootloader: A Guide To STM32 Development

While things like the Arduino platform certainly opened up the gates of microcontroller programming to a much wider audience, it can also be limiting in some ways. The Arduino IDE, for example, abstracts away plenty of the underlying machinations of the hardware, and the vast amount of libraries can contribute to this effect as well. It’s not a problem if you just need a project to get up and running, in fact, that’s one of its greatest strengths. But for understanding the underlying hardware we’d recommend taking a look at something like this video series on the STM32 platform.

The series comes to us from [Francis Stokes] of Low Byte Productions who has produced eighteen videos for working with the STM32 Cortex-M4 microcontroller. The videos start by getting a developer environment up and blinking LEDs, and then move on to using peripherals for more complex tasks. The project then moves on to more advanced topics and divides into two parts, the development of an application and also a bootloader. The bootloader begins relatively simply, and then goes on to get more and more features built into it. It eventually can validate and update firmware, and includes cryptographic signing (although [Francis] notes that you probably shouldn’t use this feature for production).

One of the primary goals for [Francis], apart from the actual coding and development, was to liven up a subject matter that is often seen as dry, which we think was accomplished quite well. A number of future videos are planned as well. But, if you’re not convinced that the STM32 platform is the correct choice for you, we did publish a feature a while back outlining a few other choices that might provide some other options to consider.

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