Curve Tracing On Spray Painted CRTs

February 24, 2019 by Brian Benchoff 16 Comments

A Lissajous curve is formed when two sine waves plotted on their respective X and Y axes. You can see one using an oscilloscope and a couple of signal generators, if you play with one of those ‘pendulums tracing in the sand’ toys, or if you really need something sciencey for your home decor you can trace them out with a disassembled CRT. That’s what [Emily] did with the LissaJukebox. It traces curves. No, it’s not a curve tracer, that’s another tool altogether

If you’re going to put squigglies on a CRT, you obviously need a CRT, and it needs to look good. There are a few options out there, from old oscilloscope tubes, the CRTs found in old VHS camcorders, to tiny electrostatic tubes that are slightly easier to drive. For this build, [Emily] chose an old, bog-standard, black and white television. But the screen is green, right? Yeah, but if you carefully mask off a CRT and buy some stained glass spray paint, a CRT can be any color you want. Except for purple, the purple stained glass spray paint didn’t work for some reason.

To generate the various functions, [Emily] used an XR2206 function generator, sold in kit form on Amazon, eBay, and various other online retailers for a pittance. One of these function generators controls the X axis, another the Y, and both of these generators are fed into a 15 Watt stereo amplifier board to run the deflection coils in the CRT. If you’re following along at home, yes, this is dangerous. Don’t touch the CRT or it will stop your heart. Those of us whose hearts are as black as coal are safe.

There were a few modifications needed to turn the XR2206 function generator ‘kit’ into something a bit more useful for this project. The through-hole pots were replaced with panel-mount pots, and the range/amplitude setting is now controlled with a rotary switch.

Is it useful? Well, actually, if you’re building a set for a TV show and you need something that looks ‘sciencey’, a LissaJukebox should be right up your alley. Other than that it looks pretty, and we now know there’s a spray paint that will turn your old, boring black and white CRT into a glorious amber phosphor. Can’t beat that.

Well-Protected USB Power Strip Makes It Easy To Plug In

February 24, 2019 by Dan Maloney 24 Comments

When we get a new device these days, somewhere in the package is likely to be a wall-wart USB power supply. We look for a place to plug in the little switch-mode dongle, rearrange a few plugs in the mains power strip, and curse its designers for the overly cozy outlet spacing. And all the while that USB-A plug on the power supply cable taunts us with its neat, compact form factor. If only there were a USB power strip.

Unwilling to suffer such indignity any longer, [Scott M. Baker] took matters into his own hands and designed this USB power distribution system. We were surprised to hear that he was unable to find a commercial USB power strip, but even if he had, it likely wouldn’t have had the bells and whistles that he added to his. The circuit went through a couple of revs, but each was focused on protection of the connected USB devices. He included both overcurrent protection, in the form of an electronic fuse built around a TPS2421 hot-swap controller, and overvoltage protection using a crowbar circuit with the usual zener-SCR arrangement. There’s also a transient voltage suppression diode to keep any inductive spikes at bay. Interestingly, each USB outlet has all these protections – it’s not just one protected bus feeding a bunch of USB outlets in parallel, but individual modules with all the circuitry. The modules are gangable and live inside a laser-cut acrylic case. The video below shows the design and build process in some detail.

We have to say that we always learn a lot about circuit design from [Scott]’s projects. You may recall his custom Atari 2600 controller or his dual-port memory retro game console, both interesting and instructive builds in their own right.

Continue reading “Well-Protected USB Power Strip Makes It Easy To Plug In” →

Mustang Dash Becomes Bookshelf Art Piece

February 24, 2019 by Lewin Day 17 Comments

Despite most of the common gauges remaining the same over the last 60 years, the automotive dashboard of days past used very different technology to those today. Cable driven speedometers were common, along with mechanical drive for the odometer, too. Fuel and temperature gauges were often wired directly to their senders, and some oil pressure gauges actually ran an oil line right up to the back of the dash. Now, things are mostly handled over the CAN bus, which inspired [Thomas]’s bookshelf-based Mustang build.

The idea behind the project is to build a nice piece of bookshelf art, using a modern CAN-driven Mustang dashboard. Through research and much trial and error, [Thomas] was able to figure out the CAN messages necessary to interface with a 2009 Mustang dashboard. There were innumerable hiccups along the way – [Thomas] had to 3D print his own connectors, reflash CAN bus interfaces, and make more than a few educated guesses to get things working.

The dash is combined with an Arduino with an MP3 shield and a 30 watt audio system, which provides both CAN signals to drive the dash as well as the obligatory sound effects of a Mustang tearing about town. It’s all finished up with an ignition keyswitch and 3 LED-lit buttons in the traditional Mustang colors.

It’s a fun build which does a great job of showcasing the basic tools and techniques required to interface with modern automotive subsystems. Salvaging an instrument cluster can be a great way to add immersion to your home racing sim, too. Video after the break.

Continue reading “Mustang Dash Becomes Bookshelf Art Piece” →

Pathio: New 3D Slicer From E3D

February 24, 2019 by Al Williams 35 Comments

Having a great word processor won’t actually help you write the next bestselling novel. It might make it easier, but if you have a great novel in you, you could probably write it on paper towels with a crayon if you had to. A great 3D printer isn’t all you need to make great 3D prints. A lot depends on the model you start with and that software known as a slicer. You have several choices, and now you have one more: PathIO, a slicer sponsored by E3D, is out in beta. You can see a video about its features below.

The software has a few rough edges as you might expect from a beta. The slicer doesn’t feed Gcode to a printer directly, although Octoprint integration is forthcoming. Developers say they are focusing on the slicing engine which is totally new. According to their website, conventional slicers immediately cut a model into 2D slices and then decide how to realize each slice with respect to the shell and infill. Pathio works in 3D space and claims this has benefits for producing correct wall thickness and an increase in self-supporting geometries.

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DAT, The HD Video Tape Format We Never Knew We Had

February 24, 2019 by Jenny List 48 Comments

When we consume our music online via streaming services it is easy to forget the days of recordings being contained on physical media, and to overlook the plethora of competing formats that vied for space in our hi-fi systems to play them. [Andrew Rossignol] has an eye for dated recording media formats as a chiptune enthusiast though, because not only has he found a DAT machine from the 1990s, he’s hacked it to record HD video rather than hi-fi audio.

If you’ve not encountered DAT before, it’s best to consider the format as the equivalent of a CD player but on a tape cassette. It had its roots in the 1980s, and stored an uncompressed 16-bit CD-quality stereo audio data stream on the tape using a helical-scan mechanism similar to that found in a video cassette recorder. It was extremely expensive due to the complexity of the equipment, the music industry hated it because they thought it would be used to make pirate copies of CDs. But despite those hurdles it established a niche for itself among well-heeled musicians and audiophiles. If any Hackaday readers have encountered a DAT cassette it is most likely to have not contained audio at all but computer data, it was common in the 1990s for servers to use DAT tapes for backup purposes.

[Andrew]’s hack involves using the SPDIF digital interface on his Sony DAT player to carry compressed video data. SPDIF is a mature and well-understood standard that he calculated has a bandwidth of 187.5 kB/s, plenty to carry HD video using the H.265 compression scheme. The SPDIF data is brought into the computer via a USB sound card, and from there his software could either stream or retrieve the video. The stream is encoded into frames following the RFC1662 format to ensure synchronization, and he demonstrates it in the video below with a full explanation.

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Flying Convenience Not So Convenient

February 23, 2019 by Lewin Day 19 Comments

It’s a situation that plays out every day, all over the world – you walk into work, and there’s a full-scale foam toilet sitting on the bench, demanding to be used in a crackpot project. This time, it happened to be at the [FliteTest] workshop, and naturally, they set about making it fly.

The team at [FliteTest] are well resourced, with a laser cutter being used to quickly produce a set of custom foam board wings. However, after wing failures on their previous projects, this time the team opted for a riveted aluminium wing spar to add strength. A twin-boom tail is used to try to avoid the cistern from interfering with airflow over the elevator, and careful attention is paid to make sure the center of gravity is in the right position for stable flight.

Despite the team’s laudable efforts, the toilet (somewhat unsurprisingly) flies like crap. It just goes to show, you can strap a brushless power system on to just about anything, but aerodynamics will still be standing ready to bring it all crashing down to Earth.

We’ve seen some great builds from [FliteTest] over the years – before the throne, it was an IKEA chair that soared amongst the clouds. Video after the break.

[Thanks to Baldpower for the tip!] Continue reading “Flying Convenience Not So Convenient” →

Thinkpad T25 Gets Less Retro With Hardware Swap

February 23, 2019 by Tom Nardi 14 Comments

For many, the Thinkpad T25 was something of a dream come true. Celebrating the 25th anniversary of the venerable business-oriented laptop that hackers love so much, it featured a design inspired by “retro” Thinkpads of yore, but with modern hardware inside. Unfortunately, as it was more fan service than a serious revitalization of classic Thinkpad design, the T25 was only ever available in a single hardware configuration.

[kitsunyan] liked the look and feel of the T25, but in 2019 was already feeling a bit let down by the hardware. The screen wasn’t up to snuff, and while the CPU is an i7, it only has dual cores. To make sure the T25 is still viable down the road, it seemed the only option was to try to transplant the hardware from one of the current Thinkpad models into the anniversary chassis. It certainly wasn’t easy, but given the fact that the T25 was more of a redress than a completely new product to begin with, everything came together a lot better than you might expect.

To help put things into perspective, the T25 is basically a modified version of the T470. Last year, Lenovo replaced the T470 with the new T480 that has just the sort of hardware improvements that [kitsunyan] wanted. The T480 was more of a refresh than a complete revamp, so the actual chassis of the machine didn’t change much compared with its predecessor. That being the case, it seemed like it should be possible to transplant the newer T480 components into the T470 derived T25. Got all that straight?

[kitsunyan] was able to put this theory to the test when the opportunity to connect a T25 keyboard to the newer T480 presented itself. Since the 7-row keyboard on the anniversary edition was one of its biggest selling points, seeing if it would work on another machine was kind of a big deal. It didn’t fit physically, and some of the keys didn’t work as expected, but it at least had the same connector and didn’t let out the magic smoke. It represented the first tiny step of a much larger journey.

In the end, it took a lot of trimming, gluing, hacking, and fiddling to get all the new hardware from the T480 to fit into the T25. But if you’re brave enough, the process has been detailed exquisitely by [kitsunyan]. Not only are the part numbers listed for everything you need to order, but there’s plenty of pictures to help illustrate the modifications that need to be made to all the clips, brackets, and assorted widgets that go into a modern laptop.

While we’re very impressed by this project, we can’t say it comes as a complete surprise. We’re well aware of the incredible lengths Thinkpad aficionados will go to keep their machines running into the 21st century. But don’t just take our word for it, you too can join the ranks of the Thinkpad elite.

[Thanks to Pierre for the tip.]