Towards A 3D-Printed Neutrino Detector

June 30, 2020 by 7 Comments

Additive manufacturing techniques like fused deposition modeling, aka 3D printing, are often used for rapid prototyping. Another advantage is that it can create shapes that are too complex to be made with traditional manufacturing like CNC milling. Now, 3D printing has even found its way into particle physics as an international collaboration led by a group from CERN is developing a new plastic scintillator production technique that involves additive manufacturing.

A scintillator is a fluorescent material that can be used for particle detection through the flashes of light created by ionizing radiation. Plastic scintillators can be made by adding luminophores to a transparent polymer such as polystyrene and are usually produced by conventional techniques like injection molding.

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Who Invented The Mouse? Are You Sure?

January 17, 2020 by 40 Comments

If you ask most people who invented the mouse, they won’t know. Those that do know, will say that Doug Englebart did. In 1964 he had a box with two wheels that worked like a modern mouse as part of his work at Stanford Research Institute. There is a famous demo video from 1968 of him showing off what looks a lot like an old Mcintosh computer. Turns out, two other people may have an earlier claim to a mouse — or, at least, a trackball. So why did you never hear about those?

The UK Mouse

Ralph Benjamin worked for Britain’s Royal Navy, developing radar tracking systems for warships. Right after World War II, Ralph was working on the Comprehensive Display System — a way for ships to monitor attacking aircraft on a grid. They used a “ball tracker.” Unlike Engelbart’s mouse, it used a metallic ball riding on rubber-coated wheels. This is more like a modern non-optical mouse, although the ball tracker had you slide your hand across the ball instead of the other way around. Sort of a trackball arrangement.

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Image Sensor From Discrete Parts Delivers Glorious 1-Kilopixel Images

December 30, 2019 by 35 Comments

Chances are pretty good that you have at least one digital image sensor somewhere close to you at this moment, likely within arm’s reach. The ubiquity of digital cameras is due to how cheap these sensors have become, and how easy they are to integrate into all sorts of devices. So why in the world would someone want to build an image sensor from discrete parts that’s 12,000 times worse than the average smartphone camera? Because, why not?

[Sean Hodgins] originally started this project as a digital pinhole camera, which is why it was called “digiObscura.” The idea was to build a 32×32 array of photosensors and focus light on it using only a pinhole, but that proved optically difficult as the small aperture greatly reduced the amount of light striking the array. The sensor, though, is where the interesting stuff is. [Sean] soldered 1,024 ALS-PT19 surface-mount phototransistors to the custom PCB along with two 32-bit analog multiplexers. The multiplexers are driven by a microcontroller to select each pixel in turn, one row and one column at a time. It takes a full five seconds to scan the array, so taking a picture hearkens back to the long exposures common in the early days of photography. And sure, it’s only a 1-kilopixel image, but it works.

[Sean] has had this project cooking for a while – in fact, the multiplexers he used for the camera came up as a separate project back in 2018. We’re glad to see that he got the rest built, even with the recycled lens he used. One wonders how a 3D-printed lens would work in front of that sensor.

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The Amazon Dash Button: A Retrospective

August 27, 2019 by 38 Comments

The Internet of Things will revolutionize everything! Manufacturing? Dog walking? Coffee bean refilling? Car driving? Food eating? Put a sensor in it! The marketing makes it pretty clear that there’s no part of our lives which isn’t enhanced with The Internet of Things. Why? Because with a simple sensor and a symphony of corporate hand waving about machine learning an iPhone-style revolution is just around the corner! Enter: Amazon Dash, circa 2014.

The first product in the Dash family was actually a barcode scanning wand which was freely given to Amazon Fresh customers and designed to hang in the kitchen or magnet to the fridge. When the Fresh customer ran out of milk they could scan the carton as it was being thrown away to add it to their cart for reorder. I suspect these devices were fairly expensive, and somewhat too complex to be as frequently used as Amazon wanted (thus the extremely limited launch). Amazon’s goal here was to allow potential customers to order with an absolute minimum of friction so they can buy as much as possible. Remember the “Buy now with 1-Click” button?

That original Dash Wand was eventually upgraded to include a push button activated Alexa (barcode scanner and fridge magnet intact) and is generally available. But Amazon had pinned its hopes on a new beau. Mid 2015 Amazon introduced the Dash Replenishment Service along with a product to be it’s exemplar – the Dash Button. The Dash Button was to be the 1-Click button of the physical world. The barcode-scanning Wands require the user to remember the Wand was nearby, find a barcode, scan it, then remember to go to their cart and order the product. Too many steps, too many places to get off Mr. Bezos’ Wild Ride of Commerce. The Dash Buttons were simple! Press the button, get the labeled product shipped to a preconfigured address. Each button was purchased (for $5, with a $5 coupon) with a particular brand affinity, then configured online to purchase a specific product when pressed. In the marketing materials, happy families put them on washing machines to buy Tide, or in a kitchen cabinet to buy paper towels. Pretty clever, it really is a Buy now with 1-Click button for the physical world.

There were two versions of the Dash button. Both have the same user interface and work in fundamentally the same way. They have a single button (the software can recognize a few click patterns), a single RGB LED (‘natch), and a microphone (no, it didn’t listen to you, but we’ll come back to this). They also had a WiFi radio. Version two (silently released in 2016) added Bluetooth and completely changed the electrical innards, though to no user facing effect.

In February 2019, Amazon stopped selling the Dash Buttons. Continue reading “The Amazon Dash Button: A Retrospective” →

Anti-Lock Brakes For Bike Might Make Rides A Little Safer

February 17, 2019 by 59 Comments

Crashing one’s bike is a childhood rite of passage, one that can teach valuable lessons in applied physics. Assuming the kid is properly protected and the crash is fairly tame, scrapes and bruises are exchanged for the wisdom to avoid sand and gravel patches, and how to avoid a ballistic dismount by not applying the front brakes harder than or before the rear brakes.

But for many of us, those lessons were learned long ago using a body far more flexible than the version we’re currently in, and the stakes are higher for a bike ride that includes braking mistakes. To help with that, [Tom Stanton] has been working on anti-lock brakes for bicycles, and in the process he’s learned a lot about the physics and engineering of controlled deceleration.

It seems a simple concept – use a sensor to detect when a wheel is slipping due to decreased friction between the tire and the roadway, and release braking force repeatedly through an actuator to allow the driver or rider to maintain control while stopping. But that abstracts away a ton of detail, which [Tom] quickly got bogged down in. With a photosensor on the front wheel and a stepper motor to override brake lever inputs, he was able to modulate the braking force, but not with the responsiveness needed to maintain control. Several iterations later, [Tom] hit on the right combination of sensors, actuators, and algorithms to make a decent bike ABS system. The video below has all the details of the build and testing.

[Tom] admits bike ABS isn’t much of an innovation. We even covered an Arduino-instrumented bike that was to be an ABS testbed a few years back. But it’s still cool to see how much goes into anti-lock systems.

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The Amazing Hacks Of World Create Day

April 4, 2018 by 5 Comments

For this year’s Hackaday Prize, we started an amazing experiment. World Create Day organized hundreds of hackerspaces around the world to come together and Build Hope for the future. This was an experiment to bring community shops and workspaces together to prototype their entries for the Hackaday Prize, and boy was it a success. We had hackerspaces from Portland to Pakistan taking part, and these are just a few of the amazing hacks they pulled off.

Students In Canada Repairing LipSyncs!

The theme of this year’s Hackaday Prize is to Build Hope, and students in Burnaby, British Columbia worked on some very cool projects that did just that. They created custom video game controllers, prototyped a few exoskeleton arms, and repaired LipSyncs. A LipSync is a mouth-operated joystick that allows a person to control a cursor on a computer with a minimum amount of head and neck movement. The idea behind the LipSync is to give wheelchair-bound people access to computers. This is important because an estimated one million people in Canada and the United States have limited or no use of their arms, rendering touchscreens inoperable.

The LipSync was an entry into the 2016 Hackaday Prize, and while it didn’t win the grand prize, it did bring a device that usually costs $3,000 down to about $300. That’s an order of magnitude of cost reduction that Builds Hope for the future. It’s amazing!

Raspberry Pis and Tschunk Slushies!

You might think that mixing alcohol and electronics might be dangerous, but not the people of kraut space, the hackerspace in Jena, Germany. For their World Create Day adventures, they made Tschunk Slushies! What is Tschunk? It’s rum and Club Mate, the definitive hacker drink! You might even say the addition of ethanol made it even more of a hacker drink. Ha ha.

While the Tschunk Slushies were mixing up, the team at the Jena Hackerspace set to work on their World Create Day project, an interface that logs their electricity usage. In reality this is just a photosensor taped to their power meter, but they’ve hooked everything up to a Raspberry Pi, giving them the ability to monitor electricity consumption over the Internet. That’s amazing. Governments and utility companies have spent billions of dollars developing ‘smart’ electricity meters, but a few ‘hackers’ have created their own in just hours! It’s almost as if that ‘hacker’ title isn’t bad at all, and being a ‘hacker’ is a good thing!

Making Laser Cutters Safe And Soldering Keychains

You’ll shoot your eye out, kid! Or at least you stand a decent chance of suffering irreversible eye damage if you’re running a laser cutter with the lid open. And for some reason, most of the cheap laser cutters out there come without safety interlocks if you can believe it. For his World Create Day Project, [RoboterFreak] made a laser cutter more secure. By putting a relay, microswitch, and Arduino in line with the laser tube, you can safely modify an off-the-shelf laser cutter to be vastly safer.

It’s not much, but it goes a long way toward making a laser cutter safe. With the simple addition of a switch, this laser cutter is now a machine that can be used within a quarter mile of children. This is something simple that you should do at your own hackerspace.

But World Create Day and the Hackaday Prize isn’t only about fretting over safety concerns. The folks at Thimble.io had fun soldering their own keychain flashlight. This is an awesome way to learn how to solder and hardware development. That’s exactly what we’re looking for in this year’s Hackaday Prize, by the way. We want people who will Build Hardware to Change The World.

The Hackaday Prize is running until November, and there’s still plenty of time to get your entry in. It doesn’t even have to be related to World Create Day, the most amazing virtual congregation of hackerspaces the world has ever seen. You can start your entry for the Hackaday Prize right here, build a project that will Build Hope, and be in the running to win tens of thousands of dollars. It’s an amazing contest, and we couldn’t have done it without the support of our amazing online community.

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Color Spaces: The Model At The End Of The Rainbow

March 30, 2018 by 23 Comments

When I learned about colors in grade school everything started with red, yellow, and blue and getting fancier colors was easy. I mixed some blue into my yellow to get green, or into red to get purple, and so on. After painting enough terrifying “art” for my parents, this made intuitive sense. That is until my mind was blown by the revelation that this wasn’t always true! 

To make the same colors with light instead of paint I had to use red, green, and blue, not yellow. It was until much later when trying harness banks of RGB LEDs that this knowledge became useful. I was struggling to make my rogue diodes look quite the way I wanted when I stumbled into the realization that maybe there was another approach. What did the numbers representing R G and B actually mean? Why those parameters? Could there be others? [Elliot Williams] has written about the importance of gamma correction and adjustment for human perception of color, but we can ask a more fundamental question. Why do we represent color this way at all?

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