JITX Spits Out Handy USB Cable Tester

May 31, 2023 by Bryan Cockfield 12 Comments

When USB first came on the scene, one of the benefits was that essentially any four conductors could get you to the point where you could send information at 12 Mbps. Of course everything is faster these days, and reaching today’s speeds requires a little bit more fidelity in the cables. This simple tester makes sure that your modern cables are actually up to the task.

One of the design goals of this project is to automate away the task of testing cables or finding one that works, especially before thinking a problem with a device is somewhere in software, spending hours or days debugging, before realizing that it’s actually being caused by a hardware malfunction. The small PCB has two USB-C fittings to plug in both of the ends of a cable to, and between those connectors there is a number of LEDs. Each LED is paired to one the many conductors within the USB cable, and not only does it show continuity of these conductors but it can also show a high resistance connection via a dimly-lit or off-color display from an LED.

One of the other interesting facets of this build is the use of JITX, which is a software-defined electronics CAD tool which allows PCB design to be automated by writing out the requirements of the PCB into code, rather than drawing it manually. It’s worth a look, and a lot of the schematics of this particular project as well as some discussion on this software can be found on the project’s GitHub page. Incidentally, if this tester looks familiar, it’s probably because your’re thinking of the open source hardware USB tester created by [Álvaro Prieto].

Op-Amp Challenge: Light Up Breadboard Shows Us The Signals

May 5, 2023 by Jenny List 5 Comments

Most Hackaday readers will no doubt at some point used a solderless breadboard for prototyping. They do the job, but sometimes their layout can be inflexible and keeping track of signals can be a pain. There’s a neat idea from [rasmusviil0] which might go some way to making the humble breadboard easier to use, it’s a breadboard in which each line is coupled via an op-amp buffer to an LED. In this way it can be seen at a glance some indication of the DC voltage present.

It’s an idea reminiscent of those simple logic probes which were popular years ago, but its implementation is not entirely easy. Each circuit is simple enough, but to replicate it across all the lines in a breadboard makes for a huge amount of quad op-amp chips stuffed onto one piece of stripboard as well as a veritable forest of wires beneath the board.

The effect is of a breadboard crossed with a set of blinkenlights, and we could see that for simple digital circuits it could have some utility if not so much for higher frequency or analogue signals. Certainly it’s an experiment worth doing, and indeed it’s not the first tricked out breadboard we’ve seen.

Hacking Hue Lightbulbs

May 4, 2023 by Al Williams 13 Comments

What do you do with a Hue smart lightbulb? Well, if you are [Chris Greening], you take it apart and get hacking. If you ever wondered what’s inside, the teardown is pretty good, and you can also watch the video below. The potting compound, however, makes a mess.

Once you get the potting undone, there are three PCBs: an LED carrier, a power supply, and a logic board. The arrangement of the LEDs is a bit confusing, but [Chris] explains it along with providing schematics for all of the boards.

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LED Matrix Displays Get New Look Thanks To SMD Stencils

April 28, 2023 by Dan Maloney 26 Comments

Even if surface-mount skills aren’t in your repertoire, chances are pretty good that most of us are at least familiar with SMD stencils. These paper-thin laser-cut steel sheets are a handy way to apply a schmear of solder paste to the pads of a PCB before component placement and reflowing. But are stencils good for anything else?

It turns out they are, if you’ve got some plain old 8×8 LED matrix displays you want to jazz up a bit. In this case, [upir]’s displays were of the square pixel type, but this trick would work just as well for a matrix with circular elements. Most of the video below is a master class in Adobe Illustrator, which [upir] used to generate the artwork for his stencils. There are a lot of great tips here that make creating one simple shape and copying it over the whole array with the proper spacing a lot easier. He also details panelizing multiple stencils, as well as the workflow from Illustrator to manufacturing.

When lined up properly over the face of the LED matrix, the stencils have quite an effect. We really liked the narrow vertical bars, which make the LED display look a bit like a VFD. And just because [upir] chose to use the same simple shape over all the LEDs in a matrix doesn’t mean that there aren’t other options. We can see how you might use the same technique to create different icons or even alphanumeric characters to create custom LED displays. The possibilities are pretty much limited to your imagination.

This isn’t the first time we’ve seen [upir] teaching old displays new tricks.

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The Eyes Have It With This Solid State Magic Eye

April 12, 2023 by Dan Maloney 7 Comments

The classic “Magic Eye” tuning indicator was a fantastic piece of vacuum tube technology that graced all kinds of electronic gear for a fair fraction of the 20th century. But despite its prevalence, finding a new-old-stock Magic Eye tube is a tall order these days, especially for the rare versions like the 6T5. No worries, though, since direct plug-in solid-state replacements for the 6T5 are now a thing, thanks to [Gord Rabjohn]. Continue reading “The Eyes Have It With This Solid State Magic Eye” →

IOT Message Board Puts Fourteen-Segment Displays To Work

March 28, 2023 by Dan Maloney 4 Comments

We’re not sure, but the number of recognizable alphanumeric characters that a seven-segment display can manage seems to have more to do with human pattern recognition than engineering. It takes some imagination, and perhaps a little squinting, to discern some characters, though. Arguably better is the fourteen-segment display, which has been pressed into service in this just-for-funsies IOT message board.

As [Steve] tells the story, this is one of those “boredom-buster” projects that start with a look through the junk bin to see what presents itself. In his case, some fourteen-segment common-cathode LEDs presented themselves, and the result was a simple but fun build. [Steve] used some clever methods to get the display stuffed onto two protoboards, including mounting the current-limiting resistors cordwood-style between the boards. A Raspberry Pi drives the display through a very neatly routed ribbon cable, and the whole thing lives in a tidy wooden box.

The IOT part of the build allows the display to show messages entered on [Steve]’s web page, with a webcam live stream to close the loop. Strangely, the display seems stuck on the “HI HACKADAY!” we entered as a test after [Steve] tipped us off, so we’re not sure if we busted it or what. Apologies if we did, [Steve]. And by the way, if your cats are named [Nibble] and [Pixel], well done!

No matter what you do with them, multi-segment displays are pretty cool. But if you think they’re something new, you’ve got another think coming.

Spin Up To Speed With This Stroboscope

March 15, 2023 by Bryan Cockfield 3 Comments

A stroboscope is not the most common tool, and while they can be purchased fairly inexpensively from various online stores, they are straightforward enough tools that plenty of us could build our own mostly from parts laying around. The basic idea is to shine a flashing light on a spinning object, and when it appears stationary the stroboscope will indicate the rotational speed. There are a few specialty parts that might not be in everyone’s parts drawers, though, and [John] shows us the ins-and-outs of his own DIY stroboscope.

The effect relies on extremely precise timing, and as such the most important part of a build like this is making sure to get the LED circuitry correct so its duty cycle and frequency can be tightly controlled. [John] is using a PT4115E driver board for the LED, and is using it to power a 1W white LED which also includes its own heat sink and lens. The controls for the stroboscope are handled by an ATtiny1614 microcontroller which shows its pulse rate on a small screen. The user can control the rate the LED flashes with simple controls, and when the spinning object appears to come to a stop the only thing left to do is read this value off of the screen.

While it might seem like an overly niche tool, stroboscopes have plenty of day-to-day uses. Older cars that used a central distributor made use of a specialty stroboscope called a timing light in order to properly advance the ignition timing of the engine. They also retain some use in medical applications, and plenty of older readers may be familiar with their use adjusting the speed on record players. They can also be used to make sure the shutter speeds on cameras are calibrated correctly.

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