A rectangle-shaped wristband wearable, worn on a wrist

A Digital White Cane For The Visually Impaired

August 12, 2021 by 22 Comments

The white cane (and its many variants) is an everyday carry for many visually impaired people. This low-tech tool allows those afflicted by visual impairment to safely navigate the world around them, and has been ubiquitous in many parts of the world for decades. [Madaeon] has been hard at work going one step further in prototyping an open-source assistive wearable that could help in situations where a cane is not practical, or useful.

The T.O.F Wristband V2 alerts its wearer to nearby obstacles through vibrations, and is able to detect objects up to four meters away. As the wearer veers closer and closer to an obstacle, the vibration increases in frequency. A time-of-flight distance sensor is controlled by a Feather, and the whole system is powered by a small lithium-polymer battery. The prototype consists of just four components plus a 3D printed case and bracelet, which inevitably keeps down costs and complexity.

Version two of this project picks up where version one left off. In that project, [Madaeon] mentioned the possibility of squeezing this project down to the size of a ring. Perhaps with better battery technology, a ring-sized sensor might just be possible one day.

This isn’t the first wearable that has set out to assist the visually impaired. Back in 2019 we covered a laser-augmented glove that attempts something very similar.

By some estimates, nearly one billion people worldwide have some degree of visual impairment. Assistive devices like the T.O.F Wristband V2, and others like it, offer these people the potential for greater independence and an improved standard of living.

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Should You Be Able To Repair It? We Think So.

August 11, 2021 by 179 Comments

You own it, you should be able to fix it. So much equipment on sale today has either been designed to be impossible to maintain, unnecessarily too complex to maintain, maintainable only with specialist tooling only available to authorised service agents, or with no repair parts availability. It’s a hot-button issue in an age when sustainability is a global concern, so legislators and regulators worldwide now finally have it in their sights after years of inaction and it’s become a buzzword. But what exactly is the right to repair, and what do we want it to be?

Is It Designed For Repair?

A Nestle Dolce Gusto machine
For some reason, pod coffee makers are especially resistant to repair. Andy1982, CC BY 3.0

The first question to consider is this: does it matter whether or not you have the right to repair something, if it’s designed specifically with lack of repairability in mind? Consider a typical domestic pod coffeemaker such as a Tassimo or similar: despite being physically quite a simple device, it is designed to be especially complex to dismantle and reassemble. You just can’t get into it when something goes wrong.

Should it be the preserve of regulators to require design for easy repair? We think so. There are other forces working on the designers of home appliances; design-for-manufacture considerations and exterior appearance concerns directly affect the firm’s bottom line, while the end users’ repair experience is often at the bottom of the list, even though the benefit at a national level is obvious. That’s what laws are for.
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From Tube And Wing To Just Wing: The Future Of Airliners

August 8, 2021 by 77 Comments

Airliners have become an unremarkable part of modern life, but unless you happen to be an aircraft enthusiast, you’d be forgiven for thinking the latest Airbus model looks more or less the same as the Boeing 707 that ushered in the Jet Age. But that might soon change, with blended wing airliners looking like the next step in air travel efficiency. In the video after the break, [Real Engineering] takes us on a fascinating tour of the past and possible future of jet airliners.

Contemporary airliners all still follow the same old “tube and wing” design, but have become vastly more efficient. The latest jetliners burn almost 50% less fuel per passenger-km than they did 50 years ago. This is thanks to better engines, improved aerodynamics, reduced weight, and a vast array of other, often invisible changes. However, it’s looking like a more drastic change is needed to keep the progress going, and NASA, Boeing, and Airbus are all betting on blended wing designs to do this.

Blended wing aircraft are basically flying wings, where the cargo-carrying section of aircraft is shorter, wider, and produces lift. This layout can be used to increase the aircraft’s internal volume, and improve aerodynamic losses, by eliminating the tail. Research shows that blended wing design could reduce fuel consumption by as much as 27%. Since load and produced lift are spread more evenly along the entire width of the aircraft, it also reduces the amount of structural reinforcement required for the wings, especially at the root. The large internal volumes also allow other power sources, like hydrogen fuel cells to be used.

Blended wing aircraft are not without challenges. They are inherently unstable and require complex control systems to fly. These control systems depend on sensors, actuators, and software to work properly, and require multiple levels of redundancy. The omission of these redundancies ultimately led to the 2008 crash of a B-2 bomber, and the more recent fatal crashes of Boeing’s 737 MAX airliners. Also, unlike tubular fuselages, blended wing designs are not ideal pressure vessels. However, this is not a major problem thanks to the availability of carbon composite materials to create strong, lightweight structures.

With aircraft technology moving as fast as ever, we look forward to seeing what the future will bring. Whether it’s personal rotorcraft or commercial space flight, it sure won’t be boring.

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Wristwatch PCB Swaps Must Be In The Air

August 8, 2021 by 19 Comments

Are we seeing more wristwatch PCB swapping projects because more people are working on them, or because we saw one and they’re on our mind? The world may never know, but when it comes to design constraints, there’s a pretty fun challenge here both in fitting your electronic wizardry inside the confines of an injection molded case, and in the power budget to make your creation run on a sippy straw of battery power.

Just this morning we came across [Joey Castillo’s] sensor-watch project. He chose the Casio F-91W as the donor wristwatch. It’s got that classic Casio look of a segment LCD display capable of displaying hours, minutes, and seconds, as well as day and date. But the added bonus is that we know these have decent water resistance while still providing three buttons for user input. Sure, it’s less buttons than the pink calculator watch we saw [Dave Darko] working on earlier in the week, but which would you trust in the pool?

Replacement PCB sized to use the same battery contact and CR2016 for power [via @josecastillo]
We see that [Joey] also chose to use the ATSAML22 microcontroller and sheds some light on why: it includes a built-in segment LCD controller! If you’re a peripheral geek like us, you can read about the SLCD controller on page 924 of the datasheet (PDF), it’s a whole datasheet onto itself.

The sensor part of the sensor-watch is a flex PCB breakout that allows you to swap in whatever sensor fits your needs. The first to be reflowed at [Joey’s] bench is a BME280 humidity sensor, which is most obviously useful for the included temperature measurements, but maybe it could also alarm at moisture ingress? [Joey] says you can swap in other parts as long as they’re in the QFN or LGA size range. We think an IMU is in order since there’s a lot of fun interaction there like the watch reacting to being positioned in front of your face, or to take tap-based inputs.

We think beginning with a donor watch is brilliant since pulling off a case, especially one that keeps water out, is 97% of the battle. But when your UI is unique to the watch world, sometimes you need to start from scratch like this wooden word clock wristwatch.

Magnus-Effect RC Aircraft Is A Lot Harder Than It Looks

August 5, 2021 by 13 Comments

Conventional airfoil wings have come out on top for getting flying machines airborne over the last century, but there were a few other interesting designs that have come and gone. One of these is the Magnus effect plane, which makes use of the lift produced by a spinning cylinder. [James Whomsley] from [Project Air] decided to build one as a side project, but it ended up being a lot more challenging than what he initially suspected. (Video, embedded below.)

The Magnus effect achieved a bit of viral fame a few years when [How Ridiculous] dropped a basketball down a dam wall with some backspin. [James] T-shaped Magnus effect plane has a pair of spinning cylinders at the top to create lift, driven by a brushless motor using a belt. A second brushless motor with a propeller is on the center carbon fiber tube provides forward thrust, and a rudder provides yaw control. The battery is attached to the bottom of the tub for stability.

The very first flight looked very promising, but [James] quickly ran into a series of problems related to center of gravity, power, pitch control, and drag. After iterations of the build-crash-rebuild cycle, he ended up with larger motors and rudder, shorter “wings”, and a higher thrust motor position. This resulted in a craft still only marginally controllable, but stayed in the air for quite a while. Since the intention was never to turn it into a long-term project, James] called it a success to avoid more yak shaving, and continue work on his airboat and rocketplane.

If you are interested in building one of your own, he put all the findings of his experimentation in a short report. For more inspiration, check out the other Magnus effect plane we covered that used KFC buckets for the wings.

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FTC Rules On Right To Repair

July 27, 2021 by 59 Comments

A few days ago, the US Federal Trade Commission (FTC) came out with a 5-0 unanimous vote on its position on right to repair. (PDF) It’s great news, in that they basically agree with us all:

Restricting consumers and businesses from choosing how they repair products can substantially increase the total cost of repairs, generate harmful electronic waste, and unnecessarily increase wait times for repairs. In contrast, providing more choice in repairs can lead to lower costs, reduce e-waste by extending the useful lifespan of products, enable more timely repairs, and provide economic opportunities for entrepreneurs and local businesses.

The long version of the “Nixing the Fix” report goes on to list ways that the FTC found firms were impeding repair: ranging from poor initial design, through restrictive firmware and digital rights management (DRM), all the way down to “disparagement of non-OEM parts and independent repair services”.

While the FTC isn’t making any new laws here, they’re conveying a willingness to use the consumer-protection laws that are already on the books: the Magnuson-Moss Warranty Act and Section 5 of the FTC Act, which prohibits unfair competitive practices.

Only time will tell if this dog really has teeth, but it’s a good sign that it’s barking. And given that the European Union is heading in a similar direction, we’d be betting that repairability increases in the future.

Thanks [deshipu] for tipping us off on this one!

Get Some Close Air Support With A Nerf Drone

July 26, 2021 by 12 Comments

Working from home has the major advantage of spending more time with loved ones, but it all that time can sometimes lead to friction. [Cory] found that Nerf battles with his kids is an effective way to blow off some steam, but felt he was getting a bit too much exercise in the process. Instead, he equipped an FPV quadcopter with a 3D printed Nerf gun to take his place.

Since manually reloading the Nerf gun after every shot wasn’t an option, he needed to create an autoloader. The darts are propelled by a pair of brushless drone motors mounted side-by-side, with just enough space for a dart the squeeze between. The motors are allowed to spin up, and then a dart is loaded servo-operated plunger, out of an off-the-shelf Nerf magazine. The motors ESCs and servo is controlled by an Arduino Nano, which receives the fire command from one of the spare outputs on the drone’s flight controller. To nerf gear is easily removable from the drone, so [Cory] to also fly the drone on more peaceful missions. See the video of one of the battles after the break. [Cory] might need to find an alternative control location to prevent himself being used as cover by his adversaries.

Nerf guns are a fun and harmless way to live out your sci-fi warfare fantasies, especially with the technology we have available these days. From FPV sentry guns to auto-aiming rifles, and heavy artillery, anything is possible.

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