Learn Sailing Mechanics Without Leaving Dry Land

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.

How A Steam Bug Once Deleted All Of Someone’s User Data

In a retrospective, [Kevin Fang] takes us back to 2015, when on the Steam for Linux issue tracker [keyvin] opened an issue to report that starting the Steam client after moving the Steam folder had just wiped all of his user data, including his backup drive mounted under /media. According to [keyvin], he moved the standard ~/.local/share/steam to a drive mounted under /media and symlinked ~/.local/share/steam to this new location on the external drive. He then tried starting Steam, which failed, before Steam crashed and tried reinstalling itself. That’s when [keyvin] realized that Steam had apparently recursively deleted everything owned by his user from the root folder.

The infamous Valve code that made Linux users sad.
The infamous Valve code that made Linux users sad.

In the issue thread, user [doofy] got hit by the same bug when trying to directly start the ~/.local/share/steam/steam.sh script with debugging enabled. He then was the first to point out the rm -rf in that steam.sh script, but since this particular line is in a function only called when Steam tries to remove and reinstall itself to ‘fix’ a botched start, how did this happen? Ultimately it seems to be because of the STEAMROOT variable being set to an empty string, and another unset variable triggering the reset_steam() function, leading to the demise of all the user data.

Since then Valve has presumably fixed the issue, as no further users have filed tickets, but it’s concerning that a similar issue seems to still exist on Windows. Whether or not the original Linux issue has been fixed, it shows clearly how one should always check return values and perhaps, just maybe, never do an automated rm -rf or equivalent.

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The Giant LEGO You Always Wanted To Play With

The interlocking LEGO bricks are probably one of the most versatile toys to come out of the 20th century, but aside from the Duplo larger-sized version for smaller kids, they don’t come in what you might term grown-up sizes. This has not deterred [Veranda Vikings] though, who have come up with the fantastic idea of giant LEGO bricks made from snow.

Making them is simplicity itself given enough depth of the white stuff, simply press the lid of one of those plastic LEGO storage bins into some fresh snowfall hard enough to compact  your brick, and then lift clear a perfect icy 2 by 2 brick. Most of the post is devoted to the building escapades of some very happy kids, and we can’t help envying them the opportunity. It appears that like the LEGO fries in the cafe at Legoland in Bilund, these bricks don’t quite interlock. We think that it would be possible to press the LEGO storage lid into the bottom of them though, perhaps some readers would like to experiment.

Either way, this is a hack to warm the hearts of readers worldwide, whether they live in a country with snow or not. We’re surprised Lego themselves haven’t caught on to the idea, and sold giant snow-brick moulds.

HOPE Is On, Spread The Word

Since 1994, Hackers on Planet Earth (HOPE) has been on the short list of must-see hacker events in the United States. Held in New York every other year (global pandemics notwithstanding), it’s an event where hackers, makers, artists, and luminaries can meet and swap ideas into the wee hours of the morning. With hands-on demonstrations, art installations, an incredible roster of speakers, and all the Club-Mate you can drink, there really is something for everyone.

Tickets are now available for HOPE XV, which will be held from July 12th to the 14th in Queens. It will once again be held on the campus of St. John’s University, as the historic Hotel Pennsylvania which played host to the con since its inception was converted into a somewhat less luxurious empty lot in 2022.

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Street Photography, With RADAR!

As the art of film photography has gained once more in popularity, some of the accessories from a previous age have been reinvented, as is the case with [tdsepsilon]’s radar rangefinder. Photographers who specialized in up-close-and-personal street photography in the mid-20th century faced the problem of how to focus their cameras. The first single-lens reflex cameras (SLRs) were rare and expensive beasts, so for most this meant a mechanical rangefinder either clipped to the accessory shoe, or if you were lucky, built into the camera.

The modern equivalent uses an inexpensive 24 GHz radar module coupled to an ESP32 board with an OLED display, and fits in a rather neat 3D printed enclosure that sits again in the accessory shoe. It has a 3 meter range perfect for the street photographer, and the distance can easily be read out  and dialed in on the lens barrel.

Whenever the revival of film photography is discussed, it’s inevitable that someone will ask why, and point to the futility of using silver halides in a digital age. It’s projects like this one which answer that question, with second-hand SLRs being cheap and plentiful you might ask why use a manual rangefinder over one of them, but the answer lies in the fun of using one to get the perfect shot. Try it, you’ll enjoy it!

Some of us have been known to dabble in film photography, too.

Thanks [Joyce] for the tip.

Hardware Should Lead Software, Right?

Once upon a time, about twenty years ago, there was a Linux-based router, the Linksys WRT54G. Back then, the number of useful devices running embedded Linux was rather small, and this was a standout. Back then, getting a hacker device that wasn’t a full-fledged computer onto a WiFi network was also fairly difficult. This one, relatively inexpensive WiFi router got you both in one box, so it was no surprise that we saw rovers with WRT54Gs as their brains, among other projects.

Long Live the WRT54G

Of course, some people just wanted a better router, and thus the OpenWRT project was born as a minimal Linux system that let you do fancy stuff with the stock router. Years passed, and OpenWRT was ported to newer routers, and features were added. Software grew, and as far as we know, current versions won’t even run on the minuscule RAM of the original hardware that gave it it’s name.

Enter the ironic proposal that OpenWRT – the free software group that developed their code on a long-gone purple box – is developing their own hardware. Normally, we think of the development flow going the other way, right? But there’s a certain logic here as well. The software stack is now tried-and-true. They’ve got brand recognition, at least within the Hackaday universe. And in comparison, developing some known-good hardware to work with it is relatively easy.

We’re hardware hobbyists, and for us it’s often the case that the software is the hard part. It’s also the part that can make or break the user experience, so getting it right is crucial. On our hacker scale, we often choose a microcontroller to work with a codebase or tools that we want to use, because it’s easier to move some wires around on a PCB than it is to re-jigger a software house of cards. So maybe OpenWRT’s router proposal isn’t backwards after all? How many other examples of hardware designed to fit into existing software ecosystems can you think of?

Erasing EEPROMs Isn’t Always As Easy As It Seems

When is 14 volts not actually 14 volts? Given [Anders Nielsen]’s recent struggles with erasing an old-school EEPROM, it’s when you really need it that things tend to go pear-shaped.

A little background is perhaps in order. [Anders] is working on a scratch-built programmer for ROMs to complement his 65uino project, which puts a complete 6502 computer into the footprint of an Arduino Uno. He wisely started the ROM programmer project at the beginning, which was to generate the correct voltages for programming. This turned out to be not as easy as you might think thanks to the solderless breadboard’s parasitic effects on the MIC2288 switching boost regulator he chose.

The video below is a continuation of the programmer build, which ends up being just as fraught as the first part. Being able to generate the programming voltages is one thing; getting them onto the right pins at the right time using nothing but the 5-volt GPIOs on a microcontroller is another. In true retro fashion, [Anders] tackled that problem with a pair of small-signal transistors, which seemed to work once the resistor values were sorted, at least when applying a 12-volt signal intended to show the ROM’s hard-coded manufacturer ID on the data bus.

But erasing the ROM, which requires 14 volts while the chip enable line is held high for 100 ms, proved a little trickier. Despite multiple tries, the ROM wouldn’t erase thanks to the 14-volt rail being dragged down to around 9 volts. [Anders] fixed that with a new base resistor on the driver, to increase the current and keep the voltage up where it needs to be. Just goes to show you that the data sheets don’t always tell the whole story.

We’ve been enjoying the unfolding story of this programmer, and we’re looking forward to the next installment.

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