Hackaday Prize Entry: Visioneer Sensor HUD

Only about two percent of the blind or visually impaired work with guide animals and assistive canes have their own limitations. There are wearable devices out there that take sensor data and turn the world into something a visually impaired person can understand, but these are expensive. The Visioneer is a wearable device that was intended as a sensor package for the benefit of visually impaired persons. The key feature: it’s really inexpensive.

The Visioneer consists of a pair of sunglasses, two cameras, sensors, a Pi Zero, and bone conduction transducers for audio and vibration feedback. The Pi listens to a 3-axis accelerometer and gyroscope, a laser proximity sensor for obstacle detection within 6.5ft, and a pair of NOIR cameras. This data is processed by neural nets and OpenCV, giving the wearer motion detection and object recognition. A 2200mA battery powers it all.

When the accelerometer determines that the person is walking, the software switches into obstacle avoidance mode. However, if the wearer is standing still, the Visioneer assumes you’re looking to interact with nearby objects, leveraging object recognition software and haptic/audio cues to relay the information. It’s a great device, and unlike most commercial versions of ‘glasses-based object detection’ devices, the BOM cost on this project is only about $100. Even if you double or triple that (as you should), that’s still almost an order of magnitude of cost reduction.

Retrotechtacular: An Oceanographic Data Station Buoy For The 1960s

When we watch a TV weather report such as the ones that plaster our screens during hurricane season, it is easy to forget the scale of the achievement they represent in terms of data collection and interpretation. Huge amounts of data from a diverse array of sources feed weather models running on some of our most powerful computers, and though they don’t always forecast with complete accuracy we have become used to their getting it right often enough to be trustworthy.

It is also easy to forget that such advanced technology and the vast array of data behind it are relatively recent developments. In the middle of the twentieth century the bulk of meteorological data came from hand-recorded human observations, and meteorologists were dispatched to far-flung corners of the globe to record them. There were still significant areas of meteorological science that were closed books, and through the 1957 International Geophysical Year there was a concerted worldwide effort to close that gap.

We take for granted that many environmental readings are now taken automatically, and indeed most of us could produce an automated suite of meteorological instruments relatively easily using a microcontroller and a few sensors. In the International Geophysical Year era though this technology was still very much in its infancy, and the film below the break details the development through the early 1960s of one of the first automated remote ocean sensor buoys.

Perhaps our last sentence conjures up a vision of something small enough to hold, from all those National Geographic images of intrepid oilskin-clad scientists launching them from the decks of research vessels. But the technology of the early 1960s required something a little more substantial, so the buoy in question is a (using the units of the day) 100 ton circular platform more in the scale of a medium-sized boat. Above deck it was dominated by an HF (shortwave) discone antenna and its atmospheric instrument package. Below deck (aside from its electronic payload) it had a propane-powered internal combustion engine and generator to periodically charge its batteries. In use it would be anchored to the sea floor, and it was designed to operate even in the roughest of maritime conditions.

The film introduces the project, then looks at the design of a hull suitable for the extreme conditions like a hurricane. We see the first prototype being installed off the Florida coast in late 1964, and follow its progress through Hurricane Betsy in 1965. The mobile monitoring station in a converted passenger bus is shown in the heart of the foul weather, receiving constant telemetry from the buoy through 40 foot waves and 110 mph gusts of wind.

We are then shown the 1967 second prototype intended to be moored in the Pacific, this time equipped with a computerised data logging system. A DEC PDP-8 receives the data mounted in the bus, and are told that this buoy can store 24 hours at a stretch for transmission in one go. Top marks to the film production team for use of the word “data” in the plural.

Finally we’re told how a future network of the buoys for presumably the late 1960s and early 1970s could be served by a chain of receiving stations for near-complete coverage of the major oceans. At the height of the Cold War this aspect of the project would have been extremely important, as up-to-the-minute meteorological readings would have had considerable military value.

The film makes an engaging look at a technology few of us will ever come directly into contact with but the benefits of which we will all feel every time we see a TV weather forecast.

Continue reading “Retrotechtacular: An Oceanographic Data Station Buoy For The 1960s”

Classic British Phone Gets A Google Makeover

It may seem like an odd concept to younger readers, but there was once a time when people rented their phones rather than buying them outright. Accordingly, these phones were built like tanks, and seeing one of these sturdy classics of midcentury modern design can be a trip down memory lane for some of us. So retrofitting a retro phone with a Raspberry Pi and Google’s AIY seems like a natural project to tackle for nostalgia’s sake.

The phone that [Alasdair Allan] decided to hack was the iconic British desk telephone, the GPO-746, or at least a modern interpretation of the default rental phone from the late 60s through the 70s. But the phone’s looks were more important than its guts, which were stripped away to make room for the Raspberry Pi and Google AIY hat. [Alasdair] originally thought he’d interface the Pi to the rotary dial through DIOs, until he discovered the odd optical interface of the dialer — a mask rotates over a ring of photoresistors, one for each digit, exposing only one to light from an LED illuminated by a microswitch on the finger stop. The digital interface brings up the Google voice assistant, along with some realistic retro phone line sounds. It’s a work in progress, but you can see where [Alasdair] is in the video below.

If stuffing a Google Pi into a retro appliance sounds familiar, it might be this vintage intercom rebuild you have in mind, which [Alasdair] cites as inspiration for his build.

Continue reading “Classic British Phone Gets A Google Makeover”

There Is No Parity: Chien-Shiung Wu

Hold out your hands in front of you, palms forward. They look quite similar, but I’m sure you’re all too aware that they’re actually mirror images of each other. Your hands are chiral objects, which means they’re asymmetric but not superimposable. This property is quite interesting when studying the physical properties of matter. A chiral molecule can have completely different properties from its mirrored counterpart. In physics, producing the mirror image of something is known as parity. And in 1927, a hypothetical law known as the conservation of parity was formulated. It stated that no matter the experiment or physical interaction between objects – parity must be conserved. In other words, the results of an experiment would remain the same if you tired it again with the experiment arranged in its mirror image. There can be no distinction between left/right or clockwise/counter-clockwise in terms of any physical interaction.

Dr. Wu working with a particle accelerator via Biography.

The nuclear physicist, Chien-Shiung Wu, who would eventually prove that quantum mechanics discriminates between left- and right-handedness, was a woman, and the two men who worked out the theory behind the “Wu Experiment” received a Nobel prize for their joint work. If we think it’s strange that quantum mechanics works differently for mirror-image particles, how strange is it that a physicist wouldn’t get recognized just because of (her) gender? We’re mostly here to talk about the physics, but we’ll get back to Chien-Shiung Wu soon.

The End of Parity

Conservation of parity was the product of a physicist by the name of Eugene P. Wigner, and it would play an important role in the growing maturity of quantum mechanics. It was common knowledge that macro-world objects like planets and baseballs followed Wigner’s conservation of parity. To suggest that this law extended into the quantum world was intuitive, but not more than intuition. And at that time, it was already well known that quantum objects did not play by the same rules as classical objects. Would quantum mechanics be so strange as to care about handedness? Continue reading “There Is No Parity: Chien-Shiung Wu”

Mini Drill Made From A Motor

We love this hacked-together mini drill by [BuenaTec] that uses a DC7.2V 10K-RPM motor with a 1/8” Dremel chuck added on. Power is supplied by a USB-A cable with the data wires cut off, with a switch controlling the voltage and a rectifier diode protecting the USB port or battery pack from back voltage from the motor.

The drill isn’t very powerful, only able to bore holes in PCBs, plastic, and similar soft materials. However, you could see how just a couple more components could make it even more robust — maybe a speed controller and voltage booster? Even so, we appreciate this bare-bones, ultra-low budget approach — only the barest essentials are included, with the components held together with hot glue and solder. Also, no one is allowed to complain about their soldering iron after viewing this video.

For more projects involving motors, read up on this brushless motor made from 3D-printed parts and this guide to hand-winding quadcopter motors.

 

Laser-Cut Modular Toolbox

[ystoelen] created this modular wooden toolbox out of laser-cut 5mm plywood secured with leather hinges bolted into place. The leather strips secure the various tool boards with grommets connecting to plastic plugs. The toolboards use cross-shaped holes with laser-cut plugs and strips of elastic securing the tools, allowing each board to be uniquely configured depending on what tool is being stored there. There is a larger, “main” board, onto which smaller boards can be placed depending on what tools you’ll need.

While this is a clever approach to tool transport, we have some concerns about this project. Usually the problem with a box full of tools is that you’ve overloaded it and can’t readily lift it up. Often this involves a steel toolbox that won’t break, no matter what happens. But a plywood construct isn’t nearly that strong, and if overloaded or dropped it’s gonna take some damage.

For more toolbox inspirations, read our posts on a machine shop in a toolbox as well as this Transformers-themed portable workbench.

 

Lock In Amplifiers

If you have about an hour to kill, you might want to check out [Shahriar’s] video about the Stanford Research SR530 lock in amplifier (see below). If you know what a lock in amplifier is, it is still a pretty interesting video and if you don’t know, then it really is a must see.

Most of the time, you think of an amplifier as just a circuit that makes a small signal bigger in some way — that is, increase the voltage or increase the current. But there are whole classes of amplifiers designed to reject noise and the lock in amplifier is one of them. [Shahriar’s] video discusses the math theory behind the amplifier, shows the guts, and demonstrates a few experiments (including measuring the speed of sound), as well.

Continue reading “Lock In Amplifiers”