Adding A Laser Blaster To Classic Atari 2600 Games With Machine Vision

June 3, 2021 by 5 Comments

Remember the pistol controller for the original Atari 2600? No? Perhaps that’s because it never existed. But now that we’re living in the future, adding a pistol to the classic games of the 2600 is actually possible.

Possible, but not exactly easy. [Nick Bild]’s approach to the problem is based on machine vision, using an NVIDIA Xavier NX to run an Atari 2600 emulator. The game is projected on a wall, while a camera watches the game field. A toy pistol with a laser pointer attached to it blasts away at targets, while OpenCV is used to find the spots that have been hit by the laser. A Python program matches up the coordinates of the laser blasts with coordinates within the game, and then fires off a sequence of keyboard commands to fire the blasters in the game. Basically, the game plays itself based on where it sees the laser shots. You can check out the system in the video below.

[Nick Bild] had a busy weekend of hacking. This was the third project write-up he sent us, after his big-screen Arduboy build and his C64 smartwatch.

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Commodore Inspired Watch Puts BASIC On Your Wrist

June 2, 2021 by 2 Comments

Ask a smart watch owner what their favorite wrist-mounted feature is, and they might say it’s having all their daily information available at a glance, or the ease with which they’re able to communicate with friends and family. If they don’t mention knocking out a few lines in their wearable BASIC interpreter, then you know you aren’t talking to [Nick Bild]. His “C64 Watch” firmware for the LILYGO T-Watch 2020 not only takes some visual inspiration from the Commodore 64, but also lets you relive those early computing glory days with a functional BASIC environment.

Originally [Nick] used a teeny tiny onscreen keyboard to tap out his BASIC programs, but finding the experience to be uncomfortably like torture, he switched over to using USB. Just plug the watch into your computer, open your favorite serial terminal, and you’ll have access to the customized version of TinyBasic Plus running on the watch. To make things  even easier, he’s looking at implementing a web-based terminal over WiFi so you don’t need to plug the watch in.

When you aren’t running BASIC you’ll be treated to a Commodore-themed watch face, complete with the classic READY. prompt. A small battery indicator is hidden up in the top-right corner, and tapping on the rainbow colored “C” will launch the menu. It’s pretty simplistic, but of course what else would you expect given the source material?

Looking ahead, [Nick] says he’d also like to implement a C64 emulator into the firmware so the watch could run original software. We’re a bit skeptical about how practical that would actually be, but we’ll reserve judgement until we see it in operation. He’s also hoping other Commodore aficionados will chime in with their own improvements and new features for the watch.

You might think that a Commodore 64 emulator on your wrist would be the most outlandish way to run your old games and software, but we’d say playing Turrican in a virtual reality microcosm of the 1980s takes the cake.

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Optical Microscope Resolves Down To 40 Nanometers

June 2, 2021 by 12 Comments

Optical microscopes depend on light, of course, but they are also limited by that same light. Typically, anything under 200 nanometers just blurs together because of the wavelength of the light being used to observe it. However, engineers at the University of California San Diego have published their results using a hyperbolic metamaterial composed of silver and silica to drive optical microscopy down to below 40 nanometers. You can find the original paper online, also.

The technique also requires image processing. Light passing through the metamaterial breaks into speckles that produce low-resolution images that can combine to form high-resolution images. This so-called structured illumination technique isn’t exactly new, but previous techniques allowed about 100-nanometer resolution, much less than what the researchers were able to find using this material.

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Trials Begin For Lozenge That Rebuilds Tooth Enamel

June 2, 2021 by 48 Comments

For all the cool regenerative tricks the human body can do, it’s kind of weird that we only have one shot at tooth enamel with no way to get it back. That may be about to change, as researchers at the University of Washington have developed a lozenge that rebuilds this precious protective coating a few microns at a time and are taking it to the trial stage. Could it really work? It’s certainly something to chew on.

The lozenge uses a genetically-engineered peptide (a chain of amino acids) derived from a protein that’s involved in developing enamel in the first place, as well as with the formation of the root surface of teeth. Inside the lozenge, this peptide works alongside phosphorus and calcium ions, which are the building blocks of tooth enamel. It’s designed to bind to damaged enamel without harming the gums, tongue, or other soft tissues of the mouth.

The researchers have already verified the efficacy on teeth extracted from humans, pigs, and rats, so the trials will largely revolve around comparing it to other whitening methods and documenting their findings.

One added advantage is that the new enamel the lozenges produce is really white, because it’s brand new. These lozenges sound like an all-around great solution, especially compared with traditional whitening techniques that often make enamel weaker. The researchers are also developing an over-the-counter toothpaste and some kind of solution for hypersensitivity, which is right up our alley.

We are skeptical of course, because nothing in history thus far has been able to regenerate enamel. Then again, yours truly uses toothpaste with nano-hydroxyapatite, which is touted as a non-toxic version of the same mineral that makes up teeth and bones. Skepticism abounds with that stuff, too, although my grill looks better to me. But why settle for new enamel when you could regrow entire teeth?

Main image by Eric Moreau and thumbnail image by Kevin Bation via Unsplash

Arduino Variometer In A Mint Tin

June 2, 2021 by 20 Comments

While humans have done a pretty good job of figuring out how to fly with various mechanical contrivances, the fact remains that our natural senses aren’t really well suited to being off the ground. For example, unless you have a visual reference point, determining which way is up is quite a bit harder than you might think. Which is why pilots rely on instruments such as the variometer, that determines the current rate of climb and descent, to guide them when their eyes can’t be trusted.

It’s also a very handy thing to have when paragliding, which is why [mircemk] decided to build a hand-held version using the Arduino Nano and a BMP180 pressure sensor. Since you don’t want to be staring at a little screen in mid-air, the device conveys changes in altitude with audio tones. A rising tone means you’re moving upwards, while a lower tone indicates downward travel. In the video below, you can see that it only takes a meter or two of vertical movement before the device picks up on the change.

Looking for a simple yet rugged enclosure for the device, [mircemk] found a metal mint tin that would hold the microcontroller, sensor, buzzer, and the 9 V battery that powers it all. We know what you’re thinking, but don’t worry; holes have been popped in the sides to make sure there’s no pressure difference inside the tin. There’s plenty of room to replace the alkaline battery with a rechargeable pack and associated charge controller, but we imagine there’s a certain security in tossing in a fresh new primary cell before slipping the surly bonds of Earth.

If you’re in interested DIY instrumentation for a glider or other aircraft that actually has a proper cockpit, this sunlight readable flight computer made from a Kobo e-reader would be a great start.

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Make Your Desoldering Easier By Minding Your Own Bismuth

June 2, 2021 by 30 Comments

Any video that starts with a phase diagram has instantly earned our attention. Admittedly, we have a pretty low bar for that kind of stuff, but eye candy aside, [Robin Debreuil]’s quick outline of his technique for desoldering with the help of bismuth is worth watching.

Aside from its use in those pink gloopy solutions one takes for an upset stomach, bismuth has a lot of commercial applications. For the purposes of desoldering, though, its tendency to lower the melting point of tin and tin alloys like solder is what makes it a valuable addition to the toolkit. [Robin] starts with a demonstration of just how far a little bismuth depresses the melting point of tin solder — to about 135°. That allows plenty of time to work, and freeing leads from pads becomes a snap. He demonstrates this with some large QFP chips, which practically jump off the board. He also demonstrates a neat technique for cleaning the bismuth-tin mix off the leads, using a length of desoldering braid clamped at an angle to the vertical with some helping-hands clips. The braid wicks the bismuth-tin mix away from the leads along one side of the chip, while gravity pulls it down the braid to pool safely on the bench. Pretty slick.

Lest leaded solder fans fret, [Robin] ensures us this works well for lead-tin solder too. You won’t have to worry about breaking the bank, either; bismuth is pretty cheap and easily sourced. And as a bonus, it’s pretty non-toxic, at least as far as heavy metals go. But alas — it apparently doesn’t machine very well.

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Know Audio: Start At The Very Beginning

June 2, 2021 by 21 Comments

A lot of our projects make noise. It can be something as simple as a microcontroller driving a small speaker or a truly ambitious Hi-Fi project, but common to all of them is the desire to get that sound out in as audible and high-quality a manner as possible. We’ve been known to make fun of the more preposterous side of the Hi-Fi world at times, but behind it all there’s a basis of solid and provable audio engineering that can be brought to bear on almost any project involving sound and electronics. Perhaps it’s time to devote some time to a series exploring the topic, and what better place to start than the ultimate destination for all that sound. Any Hi-Fi is only as good as the ears of the person listening to it, so in out journey through the world of audio that’s where we’ll start. Continue reading “Know Audio: Start At The Very Beginning” →