Cool Tools: Deus Ex Autorouter

October 16, 2018 by 35 Comments

The first thing you probably asked yourself when learning how to lay out PCBs was “can’t the computer do this?” which inevitably led to the phrase “never trust the autorouter!”. Even if it hooks up a few traces the result will probably be strange to human eyes; not a design you’d want to use.

But what if the autorouter was better? What if it was so far removed from the autorouter you know that it was something else? That’s the technology that JITX provides. JITX is a company that has developed new tools that can translate a coarse textual specification of a board to KiCAD outputs autonomously.

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Just In Time For Halloween: Another Talking Skull

October 16, 2018 by 4 Comments

It isn’t a unique idea, but we liked [Eric Wiemers’s] take on the classic animated skull for Halloween. In addition to showing you the code and the wiring, the video spends some time discussing what the audio looks like and what has to happen to get it into a format suitable for the Arduino. You can see the spooky video, below.

Of course, this is also a 3D printing project, although the skull is off-the-shelf. We wondered if he felt like a brain surgeon taking the Dremel to the poor skull. To fix the two parts of the device, he used brass threaded inserts that are heat set, something we’ve seen before, but are always surprised we don’t see more often.

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The Science Of Landing On An Asteroid

October 16, 2018 by 17 Comments

Exploiting the resources of the rock-strewn expanse of space between Mars and the outer planets has been the stuff of science fiction for ages. There’s gold in them ‘thar space rocks, or diamonds, or platinum, or something that makes them attractive targets for capitalists and scientists alike. But before actually extracting the riches of the asteroid belt, stuck here as we are at the bottom of a very deep gravity well that’s very expensive to climb out of, we have to answer a few questions. Like, how does one rendezvous with an asteroid? What’s involved with maneuvering near a comparatively tiny celestial body? And most importantly, how exactly does one land on an asteroid and do any useful work?

Back in June, a spacecraft launched by the Japanese Aerospace Exploration Agency (JAXA) finally caught up to an asteroid named Ryugu after having chased it for the better part of four years. The Hayabusa2 was equipped to answer all those questions and more, and as it settled in close to the asteroid with a small fleet of robotic rovers on board, it was about to make history. Here’s how they managed to not only land on an asteroid, but how the rovers move around on the surface, and how they’ll return samples of the asteroid to Earth for study.

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Life Imitates Art: 3D Printed Banksy Frame “Shreds” Oeuvre, Prints Money

October 16, 2018 by 14 Comments

[Dave Buchanan] is giving the world his own take on the now famous shredding Banksy frame. This version has a few extra features though – like reverse shredding and printing money! Like many of us, [David] was impressed with the Banksy art auction shredding last week. We’re still not sure how he pulled it off, and the jury is still out if it was real, or all some sort of stunt involving the auction house.

[David] took his inspiration straight to CAD software, and designed a miniature version of the frame. A quick trip to the 3D printer and he had the actual frame in hand.  He even hand-painted his own copy of Girl with Balloon on canvas. Assembly didn’t quite go as planned, a few parts had to be adjusted — i.e. cut off and hot-glued together. But in the end, the hack worked – the frame would shred and un-shred the painting whenever someone cranked the handle.

If you haven’t guessed yet, [David’s] frame is a version of the classic money printing trick. What looks like two rollers is actually a simple belt drive. The mechanism pulls in one piece of paper while pushing out a hidden piece. It creates the illusion of printing money – or of shredding art. Given Banksy’s sense of humor, we can’t help but wonder if his frame worked the same way.

[David] is working on a re-design of his piece which will be easier to build — so keep an eye on his Reddit thread if you’d like to print your own.

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Performing A Chip Transplant To Resurrect A Dead Board

October 16, 2018 by 12 Comments

[Uri Shaked] accidentally touched a GPIO pin on his 3.3 V board with a 12 V alligator clip, frying the board. Sound familiar? A replacement would have cost $60, which for him wasn’t cheap. Also, he needed it for an upcoming conference so time was of the essence. His only option was to try to fix it, which in the end involved a delicate chip transplant.

Removing the shield on the Bluetooth LE boardThe board was the Pixl.js, an LCD board with the nRF52832 SoC with its ARM Cortex M4, RAM, flash, and Bluetooth LE. It also has a pre-installed Espruino JavaScript interpreter and of course the GPIO pins through which the damage was done.

Fortunately, he had the good instinct to feel the metal shield over the nRF52832 immediately after the event. It was hot. Applying 3.3 V to the board now also heated up the chip, confirming for him that the chip was short-circuiting. All he had to do was replace it.

Digging around, he found another nRF52832 on a different board. To our surprise, transplanting it and getting the board up and running again took only an hour, including the time to document it. If that sounds simple, it was only in the way that a skilled person makes something seem simple. It included plenty of delicate heat gun work, some soldering iron microsurgery, and persistence with a JLink debugger. But we’ll leave the details of the operation and its complications to his blog. You can see one of the steps in the video below.

It’s no surprise that [Uri] was able to dig up another board with the same nRF52832 chip. It’s a popular SoC, being used in tiny, pocket-sized robots, conference badges, and the Primo Core board along with a variety of other sensors.

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Circuit Bending A TV For Better Input

October 15, 2018 by 55 Comments

If you haven’t noticed, CRTs are getting hard to find. You can’t get them in Goodwill, because thrift stores don’t take giant tube TVs anymore. You can’t find them on the curb set out for the trash man, because they won’t pick them up. It’s hard to find them on eBay, because no one wants to ship them. That’s a shame, because the best way to enjoy old retrocomputers and game systems is with a CRT with RGB input. If you don’t already have one, the best you can hope for is an old CRT with a composite input.

But there’s a way. [The 8-Bit Guy] just opened up late 90s CRT TV and modded it to accept RGB input. That’s a monitor for your Apple, your Commodore, and a much better display for your Sega Genesis.

There are a few things to know before cracking open an old CRT and messing with the circuits. Every (color) CRT has three electron guns, one each for red, green, and blue. These require high voltage, and in CRTs with RGB inputs you’re looking at a circuit path that takes those inputs, amplifies them, and sends them to the gun. If the TV only has a composite input, there’s a bit of circuitry that takes that composite signal apart and sends it to the guns. In [8-bit guy]’s TV — and just about every CRT TV you would find from the mid to late 90s — there’s a ‘Jungle IC’ that handles this conversion, and most of the time there’s RGB inputs meant for the on-screen display. By simply tapping into those inputs, you can add RGB inputs with fancy-schmancy RCA jacks on the back.

While the actual process of adding RGB inputs to a late 90’s CRT will be slightly different for each individual make and model, the process is pretty much the same. It’s really just a little bit of soldering and then sitting back and playing with old computers that are finally displaying the right colors on a proper screen.

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Hams See Dark Side Of The Moon Without Pink Floyd

October 15, 2018 by 36 Comments

Ham radio operators bouncing signals off the moon have become old hat. But a ham radio transmitter on the Chinese Longjiang-2 satellite is orbiting the moon and has sent back pictures of the Earth and the dark side of the moon. The transceiver’s main purpose is to allow hams to downlink telemetry and relay messages via lunar orbit.

While the photo was received by the Dwingeloo radio telescope, reports are that other hams also picked up the signal. The entire affair has drawn in hams around the world. Some of the communications use a modulation scheme devised by [Joe Taylor, K1JT] who also happens to be a recipient of a Nobel prize for his work with pulsars. The Dwingeloo telescope has several ham radio operators including [PA3FXB] and [PE1CHQ].

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