Year: 2017

Visual Scanner Turns Obstacles Into Braille

June 9, 2017 by 8 Comments

This interesting project out of MIT aims to use technology to help visually impaired people navigate through the use of a haptic feedback belt, chest-mounted sensors, and a braille display.

The belt consists of a vibration motors controlled by what appears to be a Raspberry Pi (for the prototype anyway) with a distance sensor and camera connected as well. The core algorithm is designed to take input from the camera and distance sensors to compute the distance to obstacles, and to buzz the right motor to alert the user — fairly expected stuff. However, the project has a higher goal: to assist in identifying and using chairs.

Aiming to detect the seat and arms, the algorithm looks for three horizontal surfaces near each other, taking extra care to ensure the chair isn’t occupied. The study found that, used in conjunction with a cane, the system noticeably helped users navigate through realistic environments, as measured by minor and major collisions. Users recorded dramatically fewer collisions as compared to using the system alone or the cane alone. The project also calls for a belt-mounted braille display to relay more complicated information to the user.

We at HaD have followed along with several braille projects, including a refreshable braille display, a computer with a braille display and keyboard, and this braille printer.

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Bouncing Pack Eases Those Tired Shoulders

June 9, 2017 by 41 Comments

If you are a hillwalker, wherever your preferred stomping ground may be you’ll know the importance of a pack with a good strap system. A comfortable pack will make the difference between tiredness and agony, and can easily add a considerable difference to your daily range.

At Arizona State University’s Human Integration Laboratory, they were approached by the US Army to investigate means by which the effect of carrying a heavy backpack could be mitigated. A soldier’s full kit is extremely heavy, and while the best available webbing systems will make a contribution to the comfort of carrying it, they can only go so far. There is still the jarring effect of the impulse force of such a significant load bearing down on the soldier’s shoulders as it comes down after every step, and this when taken over a lengthy march makes a significant difference to overall endurance.

The ASU lab’s solution was to mount the load on a spring-loaded vertical actuator attached to the pack harness and frame. The on-board microcontroller judges the moment of maximum downward impulse force as the wearer comes down from a step, and applies a corresponding upward force to the actuator. Power comes from a lithium-ion battery pack. The effect is to make the load oscillate up and down, and to lessen the wear and tear on the shoulders. It does not reduce the weight you are carrying, but it does lift it off your shoulders for an instant just when you need it.

There is a video of it being tested in the sun-drenched Arizona mountains, that we’ve placed below the break.

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Casting Cylinder Heads Out Of JB Weld

June 9, 2017 by 57 Comments

Like friendship, JB Weld is magic. Rumors persist of shade tree mechanics in the Yukon repairing cracked engine blocks with JB Weld, and last month this theory was proved correct. [Project Farm] over on YouTube took a grinder to the head of a lawnmower engine, filled the gouge with JB Weld, and ran the engine for twenty minutes.

However, as with anything mechanical that doesn’t have a foul-mouthed Canadian in it, arguments ensued. ‘This was not a true test of JB Weld repairing a cracked engine block’, claimed Internet commenters, ‘I won’t even watch the video because the idea alone is click bait.’

Now, [Project Farm] is back at it. Is it possible to use JB Weld to cast an entire cylinder head for a lawnmower? It sure is. With a cast epoxy cylinder head, this engine will run for just long enough for a proof of concept.

This experiment began by casting a single monolithic block of JB Weld that’s a bit larger than the cylinder head for a lawnmower. After curing, this JB Brick was surfaced on both sides with a belt sander. No, there was no vacuum chamber or any other techniques used by people who work with epoxies for a living. With the brick surfaced, the head gasket was used to place the bolt holes, the brick was tapped for a spark plug, and a bit of the inside was Dremeled out for the valves.

After attaching the JB Weld cylinder head to a lawnmower, [Project Farm] ran the lawnmower for about a minute. Is this a proof of concept? Yes. Did it work? Absolutely. Is it the ultimate test of JB Weld and the myth of the cracked engine block? Unfortunately, no. For that, someone will have to build a real engine entirely out of JB Weld. Until then, just check out the video below.

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Hackaday Prize Entry : Cosmic Particle Detector Is Citizen Science Disguised As Art

June 9, 2017 by 8 Comments

Thanks to CERN and their work in detecting the Higgs Boson using the Large Hadron Collider (LHC), there has been a surge of interest among many to learn more about the basic building blocks of the Universe. CERN could do it due to the immense power of the LHC — capable of reaching a beam energy of almost 14TeV. Compared to this, some cosmic rays have energies as high as 3 × 1020 eV. And these cosmic rays keep raining down on Earth continuously, creating a chain reaction of particles when they interact with atmospheric molecules. By the time many of these particles reach the surface of the earth, they have mutated into “muons”, which can be detected using Geiger–Müller Tubes (GMT).

[Robert Hart] is building an array of individual cosmic ray detectors that can be distributed across a landscape to display how these cosmic rays (particles, technically) arrive as showers of muons. It’s a citizen science project disguised as an art installation.

The heart of each individual device will be a set of three Russian Geiger–Müller Tubes to detect the particles, and an RGB LED that lights up depending on the type of particle detected. There will also be an audio amplifier driving a small 1W speaker to provide some sound effects. A solar panel is used to charge the battery, which will feed the converters that generate the logic and high voltages required for the GMT array. The GMT signals pass through a pulse shaper and then through the logic gates, finally being amplified to drive the LEDs and the audio amplifier. Depending on the direction and order in which the particles pass through the GMT’s, the device will produce a bright flash of one of 4 colors — red, green, blue or white. It also triggers generation one of three musical notes — C, F, G or a combination of all three. The logic section uses coincidence detection, which has worked well for his earlier iterations. A coincidence detector is an AND logic which produces an output when two input events occur sufficiently close to each other in time. He’s experimented with several design versions, before settling on a trio of 555 monostable multivibrators to provide the initial pulse shaping, followed by some AND gates. A neat PCB design brings it all together.

While the prototypes are housed in wooden cases, he’s going to experiment with various enclosure and mounting options to see which works best — bollard lamp posts, spheres, something that hangs on a tree or tripod or is put in the ground like a paving block. Future prototypes and installations may include a software, pulse summing and solid-state detectors. Embedded below is a video of his current version of the detector, but there are several other interesting videos on his project page that are worth looking at. And if this has gotten you interested, check out this CERN brochure — LHC, The guide for a simple explanation of particle physics and information on the LHC.

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NEETS: Electronics Education Courtesy Of The US Navy

June 9, 2017 by 29 Comments

Just about everything the US Government publishes is available to the public. Granted, browsing the GPO bookstore yields a lot of highly specialized documents like a book on how to perform pediatric surgery in hostile environments. However, there are some gems if you know where to look. If you ever wanted to have a comprehensive electronics course, the US Navy’s NEETS (Navy Electricity and Electronics Training Series) is freely available and has 24 modules that cover everything from electron flow through conductors, to tubes, to transistors and integrated circuits.

There are many places you can download these in one form or another. Some of them are in HTML format. Others are in PDF, which might be easier to put on a mobile device. The Internet Archive has them, although sorting by title isn’t quite in numerical order.

Some of the content is a bit dated — the computer section talks about magnetic core and bubble memory, for example, even though the latest revision we know of was in 1998. Of course, there are also references to bits of Navy gear that probably doesn’t mean much to most of us. However, things like the shift register (from module 13) you can see above haven’t changed in a few decades, so you can still learn a lot. The phase splitter in the top banner is even more timeless (you can find it in module 8).

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Portable Jacob’s Ladder For When…You Know… You Need A Portable Jacob’s Ladder

June 9, 2017 by 32 Comments

When do you need a portable Jacob’s Ladder? We don’t know, but apparently [mitxela] doesn’t want to leave home (or the laboratory) without one. So he built a portable unit that works for a few minutes on a battery. In the video (see below), he says he wouldn’t presume to claim it was the smallest Jacob’s Ladder ever, but he thought it might be a contender.

The battery is a LiPo cell and although it might last up to four minutes, [mitxela] points out that the transistors probably wouldn’t survive that much on time, despite the heat sinks he put in place. The whole device is 45mm square and 17mm thick. Of course, the wires add some height (about 150mm total).

We were hoping to see more of the insides, but we presume this uses one of the cheap high voltage modules you can procure from the usual Far East sources–or, at least–it could. The rest is just laser cutting and workmanship.

If you haven’t encountered them before (outside of old monster movies), a Jacob’s Ladder lets high voltage ionize the air down at the bottom of the narrow gap. The ionized air is hot and rises, and the current flows through it, despite the electrodes getting further apart. Of course, that means you shouldn’t put on in your zero-gee space station.

You might think a portable Jacob’s ladders is unique. Turns out, it isn’t. If you want something easy (and perhaps not as portable), you can’t get much easier than this one.

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Retrotechtacular: Reading And Sorting Mail Automatically

June 9, 2017 by 21 Comments

We often read about the minicomputers of the 1960s, and see examples of their use in university research laboratories or medium-sized companies where they might have managed the accounts. It’s tempting though to believe that much of the world in those last decades of the analogue era remained untouched by computing, only succumbing in the decade of the microcomputer, or of the widespread use of the Internet.

What could be more synonymous with the pre-computing age than the mail system? Hundreds of years of processing hand-written letters, sorted by hand, transported by horses, boats, railroads and then motor transport, then delivered to your mailbox by your friendly local postman. How did minicomputer technology find its way into that environment?

Thus we come to today’s film, a 1970 US Postal Service short entitled “Reading And Sorting Mail Automatically”. In it we see the latest high-speed OCR systems processing thousands of letters an hour and sorting them by destination, and are treated to a description of the scanning technology.

If a Hackaday reader in 2017 was tasked with scanning and OCR-ing addresses, they would have high-resolution cameras and formidable computing power at their disposal. It wouldn’t be a trivial task to get it right, but it would be one that given suitable open-source OCR software could be achieved by most of us. By contrast the Philco engineers who manufactured the Postal Service’s  scanners would have had to create them from scratch.

This they performed in a curiously analogue manner, with a raster scan generated by a CRT. First a coarse scan to identify the address and its individual lines, then a fine scan to pick out the line they needed. An optical sensor could then pick up the reflected light and feed the information back to the computer for processing.

The description of the OCR process is a seemingly straightforward one of recognizing the individual components of letters which probably required some impressive coding to achieve in the limited resources of a 1960s minicomputer. The system couldn’t process handwriting, instead it was reserved for OCR-compatible business mail.

Finally, the address lines are compared with a database of known US cities and states, and each letter is routed to the appropriate hopper. We are shown a magnetic drum data store, the precursor of our modern hard drives, and told that it holds an impressive 10 megabytes of data. For 1970, that was evidently a lot.

It’s quaint to see what seems to be such basic computing technology presented as the last word in sophistication, but the truth is that to achieve this level of functionality and performance with the technology of that era was an extremely impressive achievement. Sit back and enjoy the film, we’ve placed it below the break.

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