Building An Archery Mech Suit To Skip Practice

August 19, 2021 by 8 Comments

According to legend, King Edward III once said: “If you want to train a longbowman, start with his grandfather.” Consistently making accurate hits with any bow, especially on moving targets, takes many hours of practice. Or, if you’re [Shane Wighton], you can spend a comparable amount of time building, debugging, and rebuilding a robotically-enhanced bow to do it.

The goal was to shoot flying targets out of the air, so [Shane] had to create a system that could track the position of the bow and the target, and automatically adjust the position of the bow and loose the arrow at exactly the right moment to intercept the target. The position tracking was done with the same Optitrack cameras [Shane] used on his robotic basketball hoop, with reflective marking balls on the bow, target, and the release mechanism. The auto-aiming is done with a two-axis rack and pinion mechanism driven by a pair of stepper motors. [Shane] first used the cheapest recurve bow he could find online, which caused accuracy issues likely related to the Archer’s paradox. The setup also made him repeatedly hit himself in the face, because the servo-operated release mechanism would release unexpectedly without having a proper anchor with his draw hand.

[Shane] eventually upgraded to a compound bow, which reduced the tension he had to hold while lining up the shot, but also increased the weight of the system dramatically. This leads him to fully embrace the mech suit look, and use a Steadicam vest to hold the weight of the bow. This finally allowed him to reliably William Tell shots and hit the flying targets.

Whether it’s an all-in-one electronic golf club, an explosive baseball bat, or a robotic pool cue, [Shane] is certainly adept at using impressive engineering skills to compensate for his lack of physical skill, or just his willfully closed eyes. Continue reading “Building An Archery Mech Suit To Skip Practice” →

Neuromorphic Computing: What Is It And Where Are We At?

August 19, 2021 by 31 Comments

For the last hundred or so years, collectively as humanity, we’ve been dreaming, thinking, writing, singing, and producing movies about a machine that could think, reason, and be intelligent in a similar way to us. The stories beginning with “Erewhon” published in 1872 by Sam Butler, Edgar Allan Poe’s “Maelzel’s Chess Player,” and the 1927 film “Metropolis” showed the idea that a machine could think and reason like a person. Not in magic or fantastical way. They drew from the automata of ancient Greece and Egypt and combined notions of philosophers such as Aristotle, Ramon Llull, Hobbes, and thousands of others.

Their notions of the human mind led them to believe that all rational thought could be expressed as algebra or logic. Later the arrival of circuits, computers, and Moore’s law led to continual speculation that human-level intelligence was just around the corner. Some have heralded it as the savior of humanity, where others portray a calamity as a second intelligent entity rises to crush the first (humans).

The flame of computerized artificial intelligence has brightly burned a few times before, such as in the 1950s, 1980s, and 2010s. Unfortunately, both prior AI booms have been followed by an “AI winter” that falls out of fashion for failing to deliver on expectations. This winter is often blamed on a lack of computer power, inadequate understanding of the brain, or hype and over-speculation. In the midst of our current AI summer, most AI researchers focus on using the steadily increasing computer power available to increase the depth of their neural nets. Despite their name, neural nets are inspired by the neurons in the brain and share only surface-level similarities.

Some researchers believe that human-level general intelligence can be achieved by simply adding more and more layers to these simplified convolutional systems fed by an ever-increasing trove of data. This point is backed up by the incredible things these networks can produce, and it gets a little better every year. However, despite what wonders deep neural nets produce, they still specialize and excel at just one thing. A superhuman Atari playing AI cannot make music or think about weather patterns without a human adding those capabilities. Furthermore, the quality of the input data dramatically impacts the quality of the net, and the ability to make an inference is limited, producing disappointing results in some domains. Some think that recurrent neural nets will never gain the sort of general intelligence and flexibility that our brains offer.

However, some researchers are trying to creating something more brainlike by, you guessed it, more closely emulates a brain. Given that we are in a golden age of computer architecture, now seems the time to create new hardware. This type of hardware is known as Neuromorphic hardware.

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Why You Can’t Make A Wearable Display With A Transparent OLED

August 19, 2021 by 38 Comments

After seeing the cheap transparent OLED displays that have recently hit the market, you might have thought of using them as an affordable way to build your own wearable display. To save you the inevitable disappointment that would result from such a build, [Zack Freedman] took it upon himself to test out the idea, and show why transparent wearable displays are a harder than it looks.

He put together a headband with integrated microcontroller that holds the transparent OLED over the user’s eye, but unfortunately, anything shown on the display ends up being more or less invisible to the wearer. As [Zack] explains in the video after the break, the human eye is physically incapable of focusing on any object at  such a short distance. Contrary to what many people might think, the hard part of wearable displays is not in the display itself, but rather the optics.  For a wearable display to work, all the light beams from the display need to be focused into your eyeball by lenses and or reflectors, without distorting your view of everything beyond the lens. This requires, lightweight and distortion-free collimators and beam splitters, which are expensive and hard to make.

While these transparent OLEDs might not make practical heads-up displays, they are still a cool part for projects like a volumetric display. It’s certainly possible to build your own smart glasses or augmented reality glasses, you just need to focus on getting the optics right.

radio direction finding

Where’s That Radio? A Brief History Of Direction Finding

August 19, 2021 by 35 Comments

We think of radio navigation and direction finding as something fairly modern. However, it might surprise you that direction finding is nearly as old as radio itself. In 1888, Heinrich Hertz noted that signals were strongest when in one orientation of a loop antenna and weakest 90 degrees rotated. By 1900, experimenters noted dipoles exhibit similar behavior and it wasn’t long before antennas were made to rotate to either maximize signal or locate the transmitter.

British radio direction finding truck from 1927; public domain
British radio direction finding truck from 1927; public domain

Of course, there is one problem. You can’t actually tell which side of the antenna is pointing to the signal with a loop or a dipole. So if the antenna is pointing north, the signal might be to the north but it could also be to the south. Still, in some cases that’s enough information.

John Stone patented a system like this in 1901. Well-known radio experimenter Lee De Forest also had a novel system in 1904. These systems all suffered from a variety of issues. At shortwave frequencies, multipath propagation can confuse the receiver and while longwave signals need very large antennas. Most of the antennas moved, but some — like one by Marconi — used multiple elements and a switch.

However, there are special cases where these limitations are acceptable. For example, when Pan Am needed to navigate airplanes over the ocean in the 1930s, Hugo Leuteritz who had worked at RCA before Pan Am, used a loop antenna at the airport to locate a transmitter on the plane. Since you knew which side of the antenna the airplane must be on, the bidirectional detection wasn’t a problem.

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Cobbled together proof-of-concept vaccination verification system, showing a dot-matrix receipt printer, a webcam for QR code scanning, and an old laptop running the software

Manitoban Makes Open Software Demo Of Proprietary Vaccine Verification Systems

August 19, 2021 by 31 Comments

[Mark Jenkins] wasn’t impressed with the Covid 19 vaccination verification systems that restaurants in Manitoba are required to use. Patrons must present a QR code, which must be verified by a mobile app available only from Apple or Google. With help from his local hackerspace, he came up with a bash script solution requiring only kilobytes vs the 50 MB of the mobile apps. [Mark] isn’t pleased with the exclusivity of the apps availability and the lack of an open API. His concern isn’t entirely theoretical, either — Google mysteriously pulled their app from the Play Store for over a week.

The interim result, shown in the video below, is a demonstration system called Alexandra. It consists of a receipt printer, a webcam being used as a QR scanner, and a 2005-era laptop running the script. This is merely a proof of concept, as [Mark] clearly notes. There is still some work to be done — for example, the method used to authenticate with the Google server is transient. But eventually [Mark] hopes to have a free software alternative soon, suitable for restaurant owners to use in their establishments.

What kinds of vaccination verifications systems, if any, are used in your part of the world? Is the system open or proprietary? Let us know in the comments below.

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ATtiny85 on circuit board with 2n2222, pushbutton, usb-c power connector, LED, and speaker.

Custom Compression Squeezes Classic Computer Choruses Into A Tiny Controller

August 19, 2021 by 14 Comments

Geeks of a certain vintage will have fond memories of games that were simplistic by today’s standards, but drew one in all the same. Their low fidelity graphics were often complimented by equally low fidelity music being forced through the afterthought of a speaker that inhabited most computers. Despite the technical constraints of the era, these games didn’t just offer gameplay. They told stories, and they were immersive in a way that some would think wouldn’t be relatable to a younger generation.

That didn’t stop [Thanassis Tsiodras] from sharing the classic “The Secret of Monkey Island” with his niece and nephew when they were young. Excited to see his family after a year of separation due to COVID-19, [Thanassis] wanted to give them a handmade gift: The music from “The Secret of Monkey Island” on a custom player. What an uncle!

[Thanassis] could have just recorded the music and played it back using any number of chips made for the purpose, but being a long time software engineer, he decided to take the scenic route to his destination. First, DOSBox was hacked to dump the speaker output into a file. Python, C, and 30 years of experience were leveraged to squeeze everything into the 8 KB storage of an ATtiny85. Doing so was no small feat, as it required that he create a custom implementation of Huffman compression to get the data small enough to fit on chip. And when it fit, but didn’t work, even more optimization was needed.

The end result was worth it however, with the music from “The Secret of Monkey Island” playing in its original form from a speaker driven by the ever so humble but useful 2n2222. [Thanassis]’ site is replete with details too intricate to post here, but too neat to miss. Watch the video below the break for a demonstration.

Continue reading “Custom Compression Squeezes Classic Computer Choruses Into A Tiny Controller” →

David Murray and Kevin Williams with an early X16 prototype

Commander X16: A Dreamy 8 Bit Computer Comes Closer To Reality

August 18, 2021 by 34 Comments

Imagine the ultimate homage to 1980s 8-bit home computers. It might  look like [David Murray] aka The 8-Bit Guy’s Commander X16.

As a core group of geeks, hackers, and developers age, we yearn for the computers of our youth. VIC-20s, Commodore Pets, 64s, 128s, Ataris, Apple IIes, and the list goes on and on. For many of us, our first hands on experience with a computer was with such a machine that is now called “retro”. Sadly, many of these relics are getting more expensive as demand increases and supplies dwindle. Working examples are harder to find, and even those can break down. Original monitors, peripherals, and accessories are also getting scarcer. This is all quite understandable when we consider that some of these classics are over 40 years old.

What was it that we loved about these old rigs that makes them so attractive? [David] decided to distil what makes a classic a classic, and then turn that list into a spec list for what he calls his “Dream Computer”. He found that things like a printed and spiral bound manual were a big part of the charm and utility of these early home computers. Booting directly to a prompt and being able to directly control the hardware was another highly desirable trait.

[David] also took the time to determine what people don’t like about these retro machines: Wacky keyboard layouts, composite video output, and glacially slow storage. Swapping multiple floppies to load a program or respooling a cassette tape is just as undesirable in 2021 as it was in 1981. Who knew?

X16 Prototype #3
The X16’s’ prototyping is still in progress.

The result of [David]’s research is the Commander X16. Inspired by the VIC-20, it’s a fresh take on the retrocomputer that only uses parts that are currently available. You can see the first video in a series about the development of the X16 below the break. Be aware that a lot of progress has been made since the video came out in 2019, but it still provides an excellent starting point for learning about the project.

The X16’s specifications read like dream list made in the mid 80s: 256 color VGA, up to 2MB memory, an 8 MHz 6502, plenty of expansion ports, and even ports for SNES style controllers.  And what else will this dream machine include? You guessed it: A spiral bound manual!

It’s not possible to list all of the great features of the X16 in this space, so check out the Commander X16 FAQ for all the details. If this project makes your heart go pitter patter, you may be interested to know that they need help with software development! An emulator is available for development. The goal is to have a healthy software ecosystem in place when the X16 launches.

You may also enjoy reading about other 6502 retrocomputer reports such as this “Brain in a vat” 6502 computer, or a guided tour of the birthplace of the 6502 and the Commodore 64 with our very own Bil Herd.

Thank you to [Truth] for bringing us a report of this fine project via the Tip Line. Keep those tips coming!

Continue reading “Commander X16: A Dreamy 8 Bit Computer Comes Closer To Reality” →