Hackaday Links: July 8, 2018

July 8, 2018 by Brian Benchoff 12 Comments

Software-defined radio has been around for years, but it’s only recently that it’s been accessible to those of us who don’t have tens of thousands of dollars worth of equipment in their lab. Here’s a new book from Analog Devices that gives you the lowdown on software-defined radio. It’s heavy on MATLAB and components from Analog, but it’s still a solid foundation for SDR.

Do you like cyberpunk? Do you like stories about rebellious people overthrowing the system? How about androids? Do you like androids? Here’s a Kickstarter that’s tying all of that together. Neptune Frost is (will be?) a movie about an e-waste village in Burundi that’s home to the ‘world’s most subversive hacking collective’, a coltan miner and an inter-sex runaway. It’s literally got everything.

Hey, this is cool, Hackaday has been cited in a journal article. The title of the article is An open-source approach to automation in organic synthesis: The flow chemical formation of benzamides using an inline liquid-liquid extraction system and a homemade 3-axis autosampling/product-collection device, and can be found in Tetrahedron Volume 74, Issue 25, 21 June 2018, Pages 3152-3157.

Asteroid day was a few days ago, and there’s a Kickstarter to go with it. The Planetary Society, headed up by Bill Nye (a science guy) is raising awareness about the threat of asteroid impacts. There’s hilarious swag that says ‘Kick Asteroid’, even though actually kicking an asteroid might be a bad idea; a gravity tractor would be the best method of nudging the orbit of an asteroid given enough time.

Last year, a company in the US trademarked the word ‘RetroPie’ and used that trademark to sell Raspberry Pis loaded up with (you guessed it) RetroPie software. This company also used the trademark to force anyone else doing the same to stop. Obviously, this didn’t sit well with the developers of RetroPie. After some generous legal help, the RetroPie trademark issue has been resolved. That’s a tip of the hat to Eckland & Blando who offered some pro bono legal work.

Ultra-Low Power, Energy Harvesting Battery Charger

July 8, 2018 by Donald Papp 10 Comments

This half-inch square ultra-low power energy harvesting LiPo cell charger by [Kris Winer] uses a low voltage solar panel to top up a small lithium-polymer cell, which together can be used as the sole power source for projects. It’s handy enough that [Kris] uses them for his own projects and offers them for sale to fellow hackers. It’s also his entry into the Power Harvesting Challenge of the Hackaday Prize.

The board is essentially a breakout board for the Texas Instrument BQ25504, configured to charge and maintain a single lithium-polymer cell. The BQ25504 is an integrated part that takes care of most of the heavy lifting and has nifty features like battery health monitoring and undervoltage protection. [Kris] has been using the board along with a small 2.2 Volt solar panel and a 150 mAh LiPo cell to power another project of his: the SensorTile environmental data logger.

It’s a practical and useful way to test things; he says that an average of 6 hours of direct sunlight daily is just enough to keep the 1.8 mA SensorTile running indefinitely. These are small amounts of power, to be sure, but it’s free and self-sustaining which is just what a remote sensing unit needs.

Amiga 2000 Emergency Repair

July 8, 2018 by Al Williams 20 Comments

Big companies spend small fortunes on making sure their computers stay running and that they can be repaired quickly in an emergency. You wouldn’t expect an emergency repair on an Amiga 2000, though. [RETR-O-MAT] bought an Amiga 2000 that did boot, but was known to have a leaky battery on the motherboard. He wanted to rush to replace the battery before the leakage caused serious damage. You can see all this in the video below.

The computer looked lightly used over its 32-year lifespan, even when the case came off. The battery corrosion was evident, though. Even the bolt holding down the motherboard was clearly corroded from the leaking battery, causing it to be very difficult to remove.

The battery leakage also made unsoldering the battery a challenge. Several chips and sockets — including the CPU — were affected, so they had to come out. You can see a nice demonstration of the “old screwdriver trick” which might be eye-opening if you’ve only worked with SMD chips.

Even if you don’t care much about the Amiga 2000, it is interesting to see inside an old computer like this and note the differences — and similarities — to modern designs. The video is as much a tear down as it is a repair story. It also might be useful if you ever face having to tear out a leaky battery on any piece of gear. Continue reading “Amiga 2000 Emergency Repair” →

Worn Train Rails Get Judged By Laser

July 8, 2018 by Donald Papp 32 Comments

[Calango] is a railway technician, and for a school final project created the Rail Wear Surveillance Trolley (RWST) which is a delightfully designed device made mainly from PVC conduit with one job: travel down a segment of train track while shining a green laser onto the rail, and capture camera images. The trolley holds both the laser and the camera at just the right angles for the camera to capture a profile of the rail’s curved surface. The images are sent via Bluetooth to a smartphone for later analysis. Rail wear can be judged by checking how well the profile of the rail conforms to the ideal profile of an unworn segment. The trolley is manually pushed by an operator, but [Calango] says that ideally, it would be self-propelled and able to inspect a length of the track then return on its own.

The project was made on a tight budget, which led to some clever solutions like using a rotary encoder attached to a wheel as a makeshift distance sensor. If things get desperate enough, it’s even possible to roll your own rotary encoder with a 3D printer and two microswitches.

Automatic Sunglasses, No Battery!

July 8, 2018 by Jenny List 26 Comments

There are some projects that are so simple they require very little description, and [Bobricius’s] automatic sunglasses definitely fit into that category. Their story starts with the fad for 3D displays a few years ago, a resurfacing of the movie business’s periodic flirtation with the third dimension in the hope of using the gimmick to bring in more moviegoers. There was a time when you could hardly encounter a new TV or graphics card without it coming with a pair of cheap plastic glasses with LCD panels instead of lenses that would alternately shutter the view for each eye to create the 3D illusion.

Of course, once everyone had seen the film with the blue aliens and tried a few other titles on their new toy, they grew tired of headaches, nausea, and half-brightness. The glasses gathered dust, and the fancy 3D telly never ventured beyond two dimensions again. Except for [Bobricius’s] glasses, that is, for he’s levered out the 3D driver electronics and replaced them with a tiny SOIC-8 solar cell. Light hits the cell, the LCD gets a charge and darkens, no light and they remain transparent. Similar to welding goggles — though they usually use a battery. It’s unclear whether they can get a little too dark on a really bright day and whether they are something akin to [Zaphod Beeblebrox]’s peril-sensitive sunglasses, but we really applaud the idea. They are so simple that this Hackaday write-up is probably longer than their write-up, but they remain a neatly executed idea and we like that.

You can, of course, use a battery, or achieve the same effect by more complex means. But if the [Beeblebrox] glasses are closer to your requirements, we’ve got that covered too.

RGB Sensor’s New Job: Cryptocurrency Trade Advisor

July 8, 2018 by Donald Papp 15 Comments

[XenonJohn] dabbles in cryptocurrency trading, and when he saw an opportunity to buy an RGB color sensor, his immediate thought — which he admitted to us would probably not be the immediate thought of most normal people — was that he could point it to his laptop screen and have it analyze the ratio of green (buy) orders to red (sell) orders being made for crypto trading. In theory, if at a given moment there are more people looking to buy than there are people looking to sell, the value of a commodity could be expected to go up slightly in the short-term. The reverse is true if a lot of sell orders coming in relative to buy orders. Having this information and possibly acting on it could be useful, but then again it might not. Either way, as far as out-of-left-field project ideas go, promoting an RGB color sensor to Cryptocurrency Trading Advisor is a pretty good one.

Since the RGB sensor only sees what is directly in front of it, [XenonJohn] assembled a sort of simple light guide. By enclosing the area of the screen that contains orders in foil-lined cardboard, the sensor can get a general approximation of the amount of red (sell orders) versus green (buy orders). The data gets read by an Arduino which does a simple analysis and sends alerts when a threshold is crossed. He dubbed it the Crypto-Eye, and a video demo is embedded below.

Continue reading “RGB Sensor’s New Job: Cryptocurrency Trade Advisor” →

Tiny Websites Have No Server

July 7, 2018 by Al Williams 50 Comments

A big trend in web services right now is the so-called serverless computing, such as Amazon’s Lambda service. The idea is you don’t have a dedicated server waiting for requests for a specific purpose. Instead, you have one server (such as Amazon’s) listening for lots of requests and on demand, you spin up an environment to process that request. Conceptually, it lets you run a bit of Javascript or some other language “in the cloud” with no dedicated server. https://itty.bitty.site takes this one step farther. The site creates self-contained websites where the content is encoded in the URL itself.

Probably the best example is to simply go to the site and click on “About itty bitty.” That page is itself encoded in its own URL. If you then click on the App link, you’ll see a calculator, showing that this isn’t just for snippets of text. While this does depend on the itty.bitty.site web host to provide the decoding framework, the decoding is done totally in your browser and the code is open source. What that means is you could host it on your own server, if you wanted to.

At first, this seems like a novelty until you start thinking about it. A small computer with an Internet connection could easily formulate these URLs to create web pages. A bigger computer could even host the itty.bitty server. Then there’s the privacy issue. At first, we were thinking that a page like this would be hard to censor since there is no centralized server with the content. But you still need the decoding framework. However, that wouldn’t stop a sophisticated user from “redirecting” to another — maybe private — decoding website and reading the page regardless of anyone’s disapproval of the content.

Continue reading “Tiny Websites Have No Server” →