Walk-Bot Is A Navigation Device For The Vision-Impaired

For the vision impaired, there are a wide variety of tools and techniques used to navigate around in the real world. Walk-bot is a device that aims to help with this task, using ultrasound to provide a greater sense of obstacles in one’s surroundings.

Is trigonometry the most useful high school maths out there? There’s an argument that says yes.

Created by [Nilay Roy Choudhury], the device is intended to be worn on the waist, and features two sets of ultrasonic sensors. One set is aimed straight ahead, while the other points upwards at an angle of 45 degrees. An infrared sensor then points downward at an angle of 45 degrees, aimed at the ground.

The distance readings from these sensors are then collated by a microcontroller, which uses trigonometry to determine the user’s actual distance to the object. When objects are closer than a given threshold, the device provides feedback to the user via a buzzer and a vibration motor. The combination of three sensors looking out at different angles helps capture a variety of obstacles, whether they be at head, chest, or knee height.

It’s unlikely that a complex electronic device would serve as a direct replacement for solutions like the tried-and-tested cane. However, that’s not to say there isn’t value in such tools, particularly when properly tested and designed to suit user’s needs.

We’ve seen some great projects regarding visual impairment before, like this rig that allows users to fly in a simulator. If you’ve been working on your own accessibility tools, don’t hesitate to drop us a line!

Ask Hackaday: What’s Your Worst Repair Win?

Like many of you, I’ve become the designated “fix-it” person for my family and friends. While it can be a lot of work — I just finished an oil change that required me to lay in a cold, wet driveway and I can’t mention in polite company the substances I was bathed in while fixing a clogged pipe last week  — I generally relish my role. I enjoy solving problems, I love working with my hands and my head, and who doesn’t like saving money and time?

But for me, the best part of being the fix-it guy is the satisfaction that comes from doing something others can’t do. I find this especially true with automotive repairs, which conventional wisdom says is strictly the province of factory-trained experts. A little bit of a hero complex, perhaps? Absolutely! After all, I don’t get paid for my repairs, so I’ve got to get a little something for the effort.

This is why a recent pair of unrelated fixes left me feeling thoroughly unsatisfied. Neither of these jobs was a clear win, at least in terms of getting the rush of being able to do something that nobody else could. At best, these were qualified wins, which both still left me feeling a little defeated. And that got me thinking that I’m probably not the only one who has had marginal repair wins like these.

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Building A Giant Remote Controlled Model Airbus A380 In A Year

A year ago [Ramy RC] set out on a momentous challenge: to build a 1:21 scale Airbus A380-800 RC model with functional engines, landing gear and all other details. Recently he finished the project and published a video with a summary of the whole build process (also linked below). The full video series can be found on the Ramy RC channel. The final RC airplane came out at a massive wingspan of 3.9 meters (12.7′), a length of 3.6 meters (11.8′) and a weight of 25 kg. This weight is carried by the full landing gear of multiple bogeys that can retract much like on the real airplane.

A range of materials were used for the body, including carbon fiber and wood, with each part carefully modeled with CAD software and 3D-printed or cut on a CNC cutter. Four ducted fans provide the propulsive power that lift this enormous model airplane into the skies, which is the only part where the noise profile doesn’t quite match that of the real A380. Even so, seeing the airplane taxing, taking off and flying through the skies makes you look twice to realize that it is in fact a scale model and not a real Emirates A380-800, also courtesy of the excruciating amount of detail to the model’s final look, down from the logos to the silver-grey lines.

We’re also quite convinced that the maiden flight of such an exquisite model has to be one of the most terrifying experiences imaginable.

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Zen And Glowing Air Bubble Displays

When you work in a medium for long enough, and you learn how it works more and more deeply, you eventually become its master. [Yukio Shinoda] is probably master of the LED bubble display.

She started out with an idea, back in 1994, of a column of water and an array of solenoids to inject air, making patterns in the bubbles. Time passed, and she began to realize these works, first in water and then switching over to glycerine for slower, more predictable, and more spherical bubbles. The latest version realizes her initial vision, after 29 years, with an 8×8 array of nozzles making 3D shapes in the slowly rising columns. Continue reading “Zen And Glowing Air Bubble Displays”

HP 33120A Repair: Shutting Down The Eye Of Sauron

When a friend of [Tom Verbeure] came into possession of two HP 33120A 15 MHz function/arbitrary waveform generators, he could not resist giving them a try. Although not exactly high-end units, the HP 33120A makes for a pretty nice unit for a home lab. During the first test run, however, [Tom] discovered that one of the units had a dead output, which made it rather useless. Undeterred, [Tom] set to work diagnosing it, helped by the repair manual and full schematics.

While the cause was quickly tracked down to the general area around an exploded MLCC, fixing the fried Zener diode that may have initiated the short on the -15V rail revealed an unpleasant surprise. To [Tom]’s horror, he saw a portal to Hell itself open when part of the PCB caught on fire due to an internal short. After making sure to capture a video of this event, he then proceeded to use a thermal camera to track down the hot spot and uses a drill to remove the short.

While one can argue with the use of a drill to remove shorts on inner layers of a PCB, ultimately the fix was effective. A look on the schematic and comparison with the functioning 33120A unit later, all it took was two bodge wires to restore functionality. After this event, [Tom]’s friend gave him the repaired unit as thanks, and definitely not because [Tom] had begun to refer to it as ‘his precious’.

A simple wooden chair with mint metallic connectors at the corners sits next to a pile of wooden pieces wrapped in leather and straps to form a backpack.

A Nomadic Chair

There’s no shortage of different types of folding or portable chairs, but designer [Jorge Penadés] built a backpack chair that will go the long haul.

Furniture that assembles without screws or glue is always intriguing, and this chair fits the bill. Using simple metal connectors and joinery, it can be setup and taken down in about two minutes without the flimsy feeling of a bag chair. With a natural finish on the wood, the connectors give a nice pop of color without feeling overwhelming. There are even some pictures of a couch version if you follow the link.

In backpack mode, the pieces are held together by leather patches and ratchet straps. [Penadés] was focused on portability over comfort with this piece, but we think this connection method could be used in the future for more comfortable furniture that is still portable.

If you’re looking for more interesting furniture, checkout this Tambour Table with a Puzzling Secret or these CNC-able Seats.

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Your Next Airport Meal May Be Delivered By Robot

Robot delivery has long been touted as a game-changing technology of the future. However, it still hasn’t cracked the big time. Drones still aren’t airdropping packages into our gutters by accident, nor are our pizzas brought to us via self-driving cars.

That’s not to say that able minds aren’t working on the problem. In one case, a group of engineers are working ton a robot that will handle the crucial duty of delivering food to hungry flyers at the airport.

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