The Chemistry And Engineering Of DIY Photochromic Glass

November 28, 2017 by Dan Maloney 7 Comments

[Ben Krasnow] is no stranger to exploring the more arcane corners of hackerdom, and the latest video on his “Applied Science” channel goes into a field few DIYers have touched: homemade glass, including the photochromic variety.

That DIY glassmaking remains a largely untapped vein is not surprising given what [Ben] learned over the last months of experimenting. With searing temperatures bordering on the unobtainable, volatile ingredients that evaporate before they can be incorporated, and a final product so reactive that a platinum crucible is the best vessel for the job, glassmaking is not easy, to say the least. Glassmaking doesn’t scale down from an industrial process very well, it seems. Nonetheless, [Ben] came up with a process that could be replicated using common enough ingredients and a simple electric kiln modded with a PID controller for pinpoint temperature setting. And while Luxottica has nothing to worry about yet, he did manage to get some clearly if subtly photochromic samples, despite the challenges.

Without a doubt, [Ben] crossed over into “mad scientist” territory a while back, and we think it’s great. What other way is there to describe a guy who has an electron microscope, a high-power ruby laser, a CT scanner, and a cookie making robot in his basement? Whatever you call it, we like the results.

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A Minimalist Weather Clock With A Unique Display

November 28, 2017 by Dan Maloney 18 Comments

If you’re looking for a home hub to display weather, time, and important family information, the formula is pretty simple: build yet another “magic mirror” project. We’re not complaining — magic mirrors look great. But if all you need is time and weather, this elegant pixel display is something just a little bit different.

Among his many criteria for the perfect hack, [Dominic] lists usefulness, visual appeal, and low cost. We’ll agree that his minimalist weather clock hits all those marks, and with the careful selection of a 16 x 32-pixel RGB display module, [Dominic] ended up giving back to the community by developing an Arduino driver for it. He points out that strips of Neopixels could have been used for the display, but they’d have ended up costing more, so the LED matrix was a sensible choice. A 3D-printed separator grid and a paper diffuser provide the proper pixelated look, and some simple animated icons display the two-day weather forecast. We find the time and temperature numerals a little hard to read, but it’s not bad considering the limited resolution of the display. And the case is a nice bit of woodworking too. Not a bad result for only €43.

We’re intrigued by the P10 LED matrix module [Dominic] used for this one. It might be a good choice for a word clock and weather station, or with his driver, a display for just about anything.

Make A Cheap Muon Detector Using Cosmicwatch

November 27, 2017 by Steven Dufresne 13 Comments

A little over a year ago we’d written about a sub $100 muon detector that MIT doctoral candidate [Spencer Axani] and a few others had put together. At the time there was little more than a paper on arxiv.org about it. Now, a few versions later they’ve refined it to the level of a kit with full instructions for making your own under the banner, CosmicWatch including PCB Gerber files for the two surface mount boards you’ll need to assemble.

What’s a muon? The Earth is under constant bombardment from cosmic rays, most of them being nuclei expelled from supernova explosions. As they collide with nuclei in our atmosphere, pions and kaons are produced, and the pions then decay into muons. These muons are similar to electrons, having a +1 or -1 charge, but with 200 times the mass.

This pion-to-muon decay happens higher than 10 km above the Earth’s surface. But the muons have a lifetime at rest of 2.2 μs. This means that the number of muons peak at around 10 km and decrease as you go down. A jetliner at 30,000 feet will encounter far more muons than will someone at the Earth’s surface where there’s one per cm² per minute, and the deeper underground you go the fewer still. This makes them useful for inferring altitude and depth.

Muon detector

How it works

How does CosmicWatch detect these muons? The working components of the detector consist of a plastic scintillator, a silicon photomultiplier (SiPM), a main circuit board which does signal amplification and peak detection among other things, and an Arduino nano.

As a muon passes through the scintillating material, some of its energy is absorbed and re-emitted as photons. Those photons are detected by the silicon photomultiplier (SiPM) which then outputs an electrical signal that is approximately 0.5 μs wide and 10-100 mV. That’s then amplified by a factor of 6. However, the amplified pulse is too brief for the Arduino nano and so it’s stretched out by the peak detector to roughly 100 μs. The Arduino samples the peak detector’s output and calculates the original pulse’s amplitude.

Their webpage has copious details on where to get the parts, the software and how to make it. However, they do assume you can either find a cheap photomultiplier somewhere or buy it in quantities of over 100 brand new, presumably as part of a school program. That bulk purchase makes the difference between a $50 part and one just over $100. But being skilled hackers we’re sure you can find other ways to save costs, and $150 for a muon detector still isn’t too unreasonable.

Detecting muons seems to have become a thing lately. Not too long ago we reported on a Hackaday prize entry for a detector that uses Russian Geiger–Müller Tubes.

Mechanical Build Lets You Jump Cacti In Real Life

November 26, 2017 by Dan Maloney 11 Comments

Simple to learn, hard to master, a lifetime to kick the habit. This applies to a lot of computer games, but the T-rex Runner game for Chrome and its various online versions are particularly insidious. So much so that the game drove one couple to build a real-world version of the digital game.

For those not familiar with the game, it’s a simple side-scroller where the goal is to jump and duck a running dinosaur over and under obstacles — think Flappy Birds, but faster paced. When deciding on a weekend hackathon project, [Uri] thought a real-life version of the game would be a natural fit, since he was already a fan of the digital version. With his girlfriend [Ariella] on the team, [Uri] was able to come up with a minimally playable version of the game, with a stepper motor providing the dino jumps and a simple straight conveyor moving the obstacles. People enjoyed it enough that version 2.0 was planned for the Chrome Developer Summit. This version was much more playable, with an oval track for the obstacles and better scorekeeping. [Uri] and [Ariella] had to expand their skills to complete the build — PCB design, E-Paper displays, laser cutting, and even metal casting were all required. The video below shows the final version — but where are the pterosaurs to duck?

Real-world jumping dinos aren’t the first physical manifestation of a digital game. As in the cyber world, Pong was first — either as an arcade version or a supersized outdoor game.

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Tindie’s Cyber Monday Deals

November 26, 2017 by Brian Benchoff 9 Comments

The holiday season is upon us, so you know what that means. It’s time to consume! Whether that means large quantities of carbohydrates or consumer electronics, ’tis the season to buy, buy, buy.

Hundreds of Tindie items are on sale right now, and everyone will find something unique, cutting edge, and sold by the people who designed it. Tindie is artisanal electronics with a cute robot dog mascot. It can’t get any better than that.

These discounts are offered by the great DIY hardware creators themselves, the ones who are making cool stuff that you want. What’s that, you say? It’s neither Black Friday nor Cyber Monday right now? It doesn’t matter, this sale started on Black Friday and will last until at least Mail Order Tuesday.

What’s cool on Tindie? Everything! There are button breakouts for old-school brick Game Boys, space chicken stickers from the guy that built the ESP8266 Deauther, a tiny digital audio player, track ocean vessels with the dAISy AIS receiver, or learn to solder with this blinky fire engine kit.

If you’re looking for even more deals, the Hackaday Store is blowing out everything. It’s a literal fire sale after I suggested deep frying the bird this year.

Students Build Electromagnetic Egg Drop Stand

November 24, 2017 by Al Williams 6 Comments

The Egg Drop is a classic way to get students into engineering, fabrication, and experimentation. It’s a challenge to build a container to protect a raw egg from cracking when dropped from various heights.

Here’s a way to add some extra hardware to use when testing each entry. It’s an electromagnetic drop stand built by several students along with [Tom Jenkins]. The stand doesn’t require anything too exotic, and it allows students to drop their eggs in a controlled manner for a fair competition. Along the way, they learn about circuits, electromagnets, and some other electronic concepts.

If this sounds familiar, it is because it builds on the egg drop project from the Teaching Channel we talked about before. The materials for that lesson have the basic outline of the drop stand, but the video really helps kids visualize it and build it.

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A Few Caps For A Faster Multimeter

November 24, 2017 by Inderpreet Singh 19 Comments

We just love it when someone takes apart a bench instrument. There is something about voiding a warranty and then making modifications that hits the spot and in a series of simple modifications, [Jack Zimmermann] dives into the guts if an Aneng AN8008.

The multimeter in question, the AN8008, is a low-cost true-RMS instrument that takes a bit longer to settle on the correct voltage reading than [Jack] would have liked. While poking around, he found that the DC rail inside the meter was host to noise spikes. He theorized that these were being coupled back from an element and proceeded to verify the decoupling arrangement.

The first step was to replace a Rubycon 100 uF capacitor with a Panasonic FM 100 µF which has an ESR of 0.4 Ohms, an improvement on the 1.4 Ohms of stock capacitor. Next came the addition of 0.1 µF, 1 µF and a 10 µF 0805 capacitors and finally a huge 1000 uF 10 V capacity which helped cut down the noise from 30 mV p-p to 3.6 mV p-p. And finally he added decoupling capacitors to the voltage reference chip in accordance with the manufacturer’s datasheet.

These small modifications improved the settling time as well as the stability of the measurements. [Jack] verifies the accuracy against a voltage reference and a bench meter which is good news considering the calibration certificate went out the door anyway.

This is one of the many DMM hacks we have covered in the past such as the Fluke 12E+ hack that enables hidden features though there may be other models out there with possible upgrades.