Review: Inkplate 2 Shrinks Down, Adds Color

December 7, 2022 by 9 Comments

Regular Hackaday readers may recall the Inkplate family of devices: open source all-in-one development boards that combine the power and versatility of the ESP32 with electronic paper displays salvaged from commercial e-readers. By taking the sharp, high-speed, displays intended for readers such as Amazon’s Kindle and bundling it together with all the hardware and software you need to make it work, the Inkplate provided a turn-key platform for anyone looking to get serious with e-paper.

Given the fact that their screens were pulled from recycled readers, it’s no surprise the previous Inkplate entries came in familiar 6 and 10 inch variants. There was even an upgraded 6 inch model that benefited from newer reader technology by adopting a touch-sensitive backlit panel, which we took a close look at last year. Their large displays make them excellent for wall mounted applications, such as a household notification center or constantly-changing art display. Plus, as you might expect, the Inkplate is an ideal choice for anyone looking to roll their own custom e-reader.

But of course, not every application needs so much screen real estate. In fact, for some tasks, such a large display could be considered a liability. Seeing a void in their existing product lineup, the folks at Soldered Electronics (previously e-radionica) have recently unveiled the diminutive Inkplate 2. This new miniature Inkplate uses the same software library as its larger predecessors, but thanks to its 2.13 inch three-color display, lends itself to a wider array of potential projects. Plus it’s considerably cheaper than the larger Inkplate models, at just $35 USD.

Considering the crowd sourced funding campaign for the Inkplate 2 blew past its goal in just 72 hours, it seems clear there’s plenty of interest in this new smaller model. But if you’re still not sure if it’s the e-paper solution you’ve been waiting for, maybe we can help — the folks at Soldered sent along a pre-production version of the Inkplate 2 for us to play around with, so let’s take it for a test drive and see what all the fuss is about.

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In My Neighborhood, We Played Asteroids…with Real Asteroids

December 7, 2022 by 12 Comments

There was a comedian in the 1980s who always said he grew up in a tough neighborhood. He claimed they played cops and robbers with real cops. They played gin rummy with real gin. Well, maybe if he knew about [Neal Agarwal]’s asteroid launcher simulation website, he would have said they played asteroids with real asteroids.

If you ever wondered what would happen if a 1,500-foot stone or iron asteroid hit your hometown going at 38,000 mph, now you can find out.  Apparently, I live far enough in the suburbs that even a 1 mile-wide iron asteroid hitting the center of Houston wouldn’t put a crater under my house. The 17-mile-wide and 2,608-foot-deep crater would release the equivalent of 399 Gigatons of TNT, but it wouldn’t reach me.

The 29-mile-wide fireball would be a different story. Oh, and the 244 dB shockwave would almost certainly reach me. So if the clothes catching on fire resulting in second- and third-degree burns didn’t get me, perhaps the shockwave would. The simulation says that zone will have 99% fatalities, and even further out, people will get severe lung damage. Eardrums burst even further away. Homes would collapse almost to the Mexican border.

The 1,000-mile-per-hour wind might present problems, too. While we are well-situated for hurricanes in this area, that’s about five times more wind than even a big hurricane generates. And we are not well prepared for earthquakes, much less the magnitude 70 quake that would occur.

Pretty bleak. On the plus side, a strike like that happens about once every 2.6 million years. If you try it yourself, be sure to scroll down the right panel to see the graphical representation of the different effects.

Maybe NASA is on to something when they tell us they want to learn to deflect asteroids. Even private foundations are getting into the business of finding them.

Merry Christmas! Rip And Tear!

December 7, 2022 by 6 Comments

If you want a little mayhem on your Christmas tree, you can check out [Sprite_tm]’s tiny PC Christmas ornament. With 3D printing, that isn’t such a tall order, but [Sprite]’s does have a unique ability: it plays DOOM, as you can see in the video below.

The device uses an ESP32, and while [Sprite] had ported the iconic shooter to the microcontroller before, he decided to use a Game Boy port that is more lightweight instead. There were a few reasons for the choice, including the ability to do Bluetooth so you could connect controllers so you can play the game. The only catch was he had to pull off the flash memory and replace it with a larger one (see the second video below).

Granted, the screen is tiny, so it is sort of a novelty. But if you want to have a go, the files are all there. As you might expect, there is a tiny battery and the circuitry required to recharge it, as well. We’d probably make an adapter to let it charge from the Christmas lights, but that can wait for version 2.

The input device handling is a bit strange. Bluetooth BLE devices will automatically grab an input device that is in pairing mode. There is no provision for connecting using the “normal” Bluetooth mechanism. A fun project and you could use the case for some other tiny projects, too. A larger flash on an ESP32 has lots of possibilities, as well.

If you need a primer on the ESP32, we got it. If you want to play DOOM on something truly strange, try seven-segment displays.

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Restarting The Grid When The Grid Is Off The Grid

December 6, 2022 by 33 Comments

If you watch YouTube long enough, it seems like going “off the grid” is all the rage these days. But what if the thing that goes off the grid is the grid itself? In the video below the break, [Grady] with Practical Engineering explores the question: How do you restart an entire power grid after it’s gone offline? It’s a brilliantly simple deep dive into what it takes to restore power to large amounts of customers without causing major damage to not just the grid, but the power generators themselves.

What’s A Power Grid Operators Favorite Band?

The hackers among us who’ve dealt with automotive alternators know it must be excited in order to generate electricity. What does that even mean, and how does it affect the grid? Simply put, it takes power to make power. For example, old heavy equipment had what they called pony motors — a small easy to start engine that’s sole purpose was to start a much larger engine. Aircraft have auxiliary power units (APUs) for the same purpose. What do power grids have? You’ll have to watch the video to find out.

Once at least two power generators are online, grid operators can just flip the switch and start feeding power to customers, right? Not quite. [Grady] once again uses a clever test jig and an oscilloscope to show the damage that can occur if things aren’t done just right. It’s a fascinating video well worth watching.

Learn how grid operators use a Power Grid Emulator called LEGOS to help them with keeping the electrons flowing in the right direction.

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PSA: Watch Out For White Filament

December 6, 2022 by 48 Comments

We all know that using 3D printing filament with exotic filament that has metal or carbon fibers in it will tend to wear standard nozzles. That’s why many people who work with filaments like that use something other than conventional brass nozzles like hardened steel. There are even nozzles that have a ruby or diamond surfaces to prevent wear. However, [Slant 3D] asserts something we didn’t know: white filament may be wearing your nozzle, too. You can see his argument in the video below.

The reason? According to Slant 3D, the problem is the colorant added to make it white: titanium dioxide. Unlike some colorants, the titanium dioxide colorant has a large grain size. The video claims that the hard titanium material has a particle size of about 200 nm, which is much larger than, say, carbon black, which is about 20 times smaller.

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How On-Frequency Are Those Cheap Radar Modules?

December 6, 2022 by 8 Comments

If you’re partial to browsing AliExpress, Banggood, or eBay for unusual hardware, you may have seen the HB100 Doppler Radar modules. These are a PCB with a metal can on board, and their reverse side has a patch antenna array. They work on a frequency of 10.525 GHz, and [OH2FTG] has characterized a few of them to see how close they lie to that figure.

These devices have a superficially very simple circuit that makes extensive use of PCB layout for creating microwave inductors, capacitors, and tuned circuits. There’s a FET oscillator and a diode mixer, and a dielectric resonator coupling the output and input inductors of the FET. This component provides the frequency stability, but its exact frequency depends on what lies within its electric field. Thus the screening can does more than screening, and has a significant effect on the frequency and stability of the oscillator.

The higher quality HB100s have a small tuning screw in the top of the can which in turn adjusts the frequency. This should be tweaked in the factory onto the correct point, but is frequently absent in the cheaper examples. In this case he has a pile of modules, and while surprisingly some are pretty close there are outliers that lie a significant distance away.

If you use an HB100 then the chances are nobody will ever bother you if it’s off-frequency, as its power output is tiny. But it’s worth knowing about their inner workings and also how to adjust them should you ever need to. Meanwhile if you’re interested in Doppler radar, here’s how to design one for a lower frequency.

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The World’s Brightest Laser Pointer?

December 6, 2022 by 37 Comments

The videos from [styropyro] are always amusing and informative. However, ironically for him, he is alarmed that many green laser pointers are more powerful than they are supposed to be. Sure, you often want a powerful laser, but if you think a laser is safe and it isn’t, you could… well… put an eye out. See the video below to see what [styropyro] claims is the brightest laser pointer in the world.

The key is a possibly gray market very large green laser array. It appears to have at least 24 lasers and some pretty serious lenses. He tested the array first with a power supply and it looked like something out of a bad science fiction movie, even at reduced power.

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