KittyOS: Writing A Toy OS For The ATmega168 From Scratch

September 5, 2022 by Dave Rowntree 6 Comments

Writing an operating system for a computing platform is one of those non-trivial tasks few people actually need to do, regardless of whether it’s for a small microcontroller or a larger general-purpose computer. Many of us spend a large amount of our time working on producing robust code for embedded systems, occasionally diving deeper into the abstraction when we’re stuck on a problem. Quite often this work is sitting on top of an RTOS, which we consider a solved problem. [Jonathan Diamond] had picked up a fair bit of knowledge of some of the low-level AVR black magic, as well as some details of how operating systems work internally, and so decided to have a crack a building a toy operating system called KittyOS, for the learning experience alone.

[Jonathan] hastens to add that this is not a practical OS, but a learning platform that needs a few more bells and whistles added to be useful. Aimed at the 8-bit AVR ATmega168 with its mere 16kB of flash and 1kB of SRAM, the diminutive chip can still perform more than well enough to host the rudimentary OS — up to four application tasks, and some basic system call support.

Already, KittyOS sports preemptive multitasking, with prioritization and support for applications written in C. Hardware support is a bit limited, with just serial I/O and a spot of GPIO, but that’s more than enough for a demonstrator. Applications can be loaded into any of the four available slots, with per-slot run state control, using the Python-based host interface. The post is a long one, with an absolute ton of the gory details we love around these parts, and we’re very glad [Jonathan] took the time to make a proper write-up as well as a demonstration video, which can be found after the break.

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Why You’ve Never Heard About Nintendo’s U-Force

September 5, 2022 by Elliot Williams 21 Comments

90’s kids think that the Power Glove was the coolest game peripheral of the epoch. We might have thought so too, until we heard about Don’t Touch: The Story of the U-Force from [The Gaming Historian].

The device itself folded up like a laptop, and on the two surfaces had four IR LED/sensor pairs. All of these combined would localize your fist in space for playing Mike Tyson’s Punch Out, or would work with various other passive controller add-ons like a flight yoke for playing Top Gun. (One of the coolest bits is the flip-out IR reflectors triggered by the buttons in the yoke.)

All-in-all, the video’s take is that a number of factors doomed the U-Force to play second fiddle to the Power Glove. Battling Mattel’s marketing prowess is obvious, but other things like manufacturing problems due to bad hinges and inconsistent IR sensors delayed release and added cost. In the end, though, [Dave Capper], the U-Force’s inventor, puts it down simply to non-convincing gameplay. There were no blockbuster games that used it to its full potential.

At the time, the U-Force utilized more IR LEDs than any other consumer electronic device.

We think there’s interesting hacker potential in a simple interface like this. Perhaps its biggest Achilles heel outside of the lack of a killer application was the fact that it required calibration. We can imagine all sorts of awesome interactions, and we’re not afraid of a little tweaking. Or maybe we would update the sensors to something more modern, like those inexpensive time-of-flight distance units.

Thanks [Karl Koscher] for bringing this documentary to our attention in the comments about the very similarly interesting laser theremin project we featured last year. It’s definitely opened our eyes to an old interaction of the past that would seem no less magical today.

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The 7805 Is Dead! Long Live The 7805!

September 5, 2022 by Al Williams 70 Comments

The 78XX series of regulators are very handy to use. If you need, say, a 5V regulator, you grab a 7805, add a capacitor for stability, and send in enough voltage for the regulator to work with. Cheap and easy. However, the part is not without its faults.

A stock 7805 can’t convert 5.1V to 5V. You need to have a good bit more voltage coming in. But the more voltage you put in, the more the part is going to dump out as heat. So running from 9V is going to be cooler than running from 24V. All that heat isn’t very energy efficient on batteries, either. [Stefan] wanted to do better, so he made a drop-in replacement for these venerable regulators some time ago. But he’s recently made the board layouts available so you can build your own replacement, too.

The device accepts 4.5 to 16V, and you can select the output voltage using two resistors. You can draw up to 2A out of the regulator, which is more than you can say for a stock 7805.

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A portable computer built inside a rugged carrying case

2022 Cyberdeck Contest: The Black Beast Will Help You Survive A Robot Apocalypse

September 4, 2022 by Robin Kearey 19 Comments

With AI systems getting smarter every day, one might wonder if they might someday evolve into a sentient Skynet-like system and try to take over the world. We’re not sure how close we are to such a situation, but we do know that if the robot apocalypse were to happen, we would want to stay close to [LordOfAllThings], who would likely be carrying the Black Beast. This scary-sounding machine is in essence a Raspberry Pi-based portable computer built inside an outdoor carrying case, with a wide range of unusual peripherals that make it the digital equivalent of a Swiss army knife. In other words, it’s a cyberdeck built for end times — and whatever comes after.

For example, an array of ESP32-based modules plus an SDR module allow you to intercept and analyze hostile robots’ communications, whether they’re using Bluetooth, WiFi, LoRaWAN, or anything in the 433 or 868 MHz ranges. An FM transmitter comes in handy for reaching out to fellow citizens who are trapped with nothing more than an analog radio receiver, while a suite of environmental sensors (including a Geiger counter) should help determine if Skynet has released any harmful substances to flush out those last few pesky humans. (Ed. note: No marigolds in the promised land and all that.)

If you manage to find a wired Ethernet connection somewhere, a built-in five-port gigabit router lets you set up a local network, obviously with a custom network analyzer to detect any unwanted intrusions. A storage compartment contains every kind of cable you could need, as well as useful gadgets like flashlights and, indeed, an actual Swiss army knife.

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Magnetic Maniac Manages Mangled Memory

September 4, 2022 by Jonathan Bennett 29 Comments

Ahh, floppy disks. Few things carry nostalgia quite like a floppy — either 3 1⁄2 or 5 1⁄4, depending on which generation of hacker you happen to be. (And yes, we hear you grey-beards, 8-inch floppies were definitely a thing.) The real goodies aren’t the floppies themselves, but what they carried, like Wolfenstein 3d, Commander Keen, DOS, or any number of other classics from the past. Unfortunately a bunch of floppy disks these aren’t carrying anything anymore, as bit rot eventually catches up with them. Even worse, on some trashed floppies, a format operation fails, too. Surely, these floppies are destined for the trash, right?
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Hackaday Links: September 4, 2022

September 4, 2022 by Dan Maloney 19 Comments

Say what you will about Tesla, but there’s little doubt that the electric vehicle maker inspires a certain degree of fanaticism in owners. We’re used to the ones who can’t stop going on about neck-snapping acceleration and a sci-fi interior. But the ones we didn’t see coming are those who feel their cars are so bad that they need to stage a hunger strike to get the attention of Tesla. The strike is being organized by a group of Tesla owners in Norway, who on their website enumerate a long list of grievances, including design defects, manufacturing issues, quality control problems, and customer service complaints. It’s not clear how many people are in the group, although we assume at least 18, as that’s the number of Tesla cars they used to spell out “HELP” in a parking lot. It’s also not clear how or even if the group is really off their feed, or if this is just a stunt to get the attention of Tesla honcho and notorious social media gadfly Elon Musk.

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Hackaday Prize 2022: Drying Clothes With Ultrasound

September 4, 2022 by Lewin Day 29 Comments

Clothes dryers are great, and a key part of modern life, but they do use a lot of energy. [Mike Rigsby] decided to see if there was a more efficient method of drying clothes that could compete with resistive heating for efficiency. Thus, he started work on an ultrasonic clothes dryer.

In early testing, he found ultrasonic transducers could indeed blast droplets of moisture away from fabric, effectively drying it. However, unlike heat, the ultrasonic field doesn’t effectively permeate through a pile of clothes, nor can it readily be used with a spinning drum to dry many garments at once.

[Mike]’s current experiments are centered around using a basket-type system, with a bed of ultrasonic transducers at the bottom. The idea is that the basket will shake back and forth, agitating the load of clothing and allowing the different garments to effectively contact the transducers. It’s still a work in progress, but it’s an interesting approach to the problem. We’d love to see a comparison of the energy use of a full-scale build versus a regular dryer.

We’ve heard of the ultrasonic drying concept before, too, with the Department of Energy researching the matter. It could just be that we’ll all be using ultrasonic dryers in decades to come!