How To Keep Unique Equipment Running When Parts Run Out

April 23, 2020 by Donald Papp 16 Comments

[JGlass] deals with public-facing technology, which he says includes things like theatre equipment, retail displays, and museum displays. Many of these pieces of technology are literally one-of-a-kind devices, even if they were constructed from what was once off-the-shelf, commercially available parts. When these machines need servicing, replacement parts aren’t always available, and reverse engineering comes in handy. He recently began documenting exactly how to approach this process by using the identification and replacement of an obsolete 7-segment industrial display as an example.

The particular part shown is the Lascar EM32-4-LED, which up and died in a unique piece of equipment. The trouble is that the EM32-4-LED is out of production and unobtainable, and the Programmable Logic Controller (PLC) that drives the whole thing is a black box that cannot be modified. It’s very good news that a datasheet exists, but that’s often just a starting point. To create a one-off, drop-in solution requires a combination of research, troubleshooting, and design work.

To do this, [JGlass] starts off by walking through datasheet elements and explains that it’s important to build a high level understanding of function first, then drill down into details, and always be ready to verify, challenge, or throw out one’s assumptions. After establishing a high level understanding comes matching physical evidence to things like block and functional diagrams, then cracking open the faulty component to see if anything else can be learned. Only then are multimeters and probes taken out for more active research. All of this sleuthing must always be done with the end goal firmly in mind: creating a new device that acts like the one being replaced. Without focus, one can easily get lost in details and unknowns.

Reverse Engineering is a process, and the more tools, the better. If you missed our earlier post about a hacker’s guide to JTAG, here’s your chance to check it out and be all the more prepared for the next time you need to do some electron detective work of your own.

DIY Magsafe Charger Feeds Off 12 V Solar Battery

April 19, 2020 by Donald Papp 18 Comments

[Steve Chamberlin] has a spiffy solar-charged 12 V battery that he was eager to use to power his laptop, but ran into a glitch. His MacBook Pro uses Apple’s MagSafe 2 connector for power, but plugging the AC adapter into the battery via a 110 VAC inverter seemed awfully inefficient. It would be much better to plug it into the battery directly, but that also was a problem. While Apple has a number of DC power adapters intended for automotive use, none exist for the MagSafe 2 connector [Steve]’s mid-2014 MacBook Pro uses. His solution was to roll his own MagSafe charger with 12 VDC input.

Since MagSafe connectors are proprietary, his first duty was to salvage one from a broken wall charger. After cleaning up the wires and repairing any frayed bits, it was time to choose a DC-DC converter to go between the MagSafe connector and the battery. The battery is nominally 12 volts, so the input of the DC-DC converter was easy to choose, but the output was a bit uncertain. Figuring out what the MagSafe connector expects took a little educated guesswork.

The original AC adapter attached to the charger claimed an output of 20 volts, another Apple adapter claimed a 14.85 V output, and a third-party adapter said 16.5 volts. [Steve] figured that the MagSafe connectors seemed fine with anything in the 15 to 20 V range, so it would be acceptable to use a 12 V to 19 V DC-DC boost converter which he had available. The result worked just fine, and [Steve] took measurements to verify that it is in fact much more efficient than had he took the easy way out with the inverter.

MagSafe has been displaced by USB-C nowadays, but there are plenty of MagSafe devices still kicking around. In a pinch, keep in mind that a little bit of filing or grinding is all that’s needed to turn MagSafe 1 into MagSafe 2.

Automatic Timelapses, Made Educational And Easy

April 16, 2020 by Donald Papp 2 Comments

Timelapse fragment from an infrared sky camera watching cloud patterns.

There are plenty of ways to create timelapse videos, but [Andy] has an efficient method for ensuring up-to-date ones exist for his infrared sky camera, and he has it running thanks to some well-documented shell scripts on a spare Raspberry Pi. The resulting timelapse video is always available from the web, and always up-to-date for the current day.

The idea is to automatically fetch images from a remote source (in his case, an infrared sky camera) and turn them into a cumulative video that is regularly updated for the day in question. The resulting video file is either served from the same machine, or sent elsewhere. All that’s needed besides a source for the stills are two shell scripts and some common Linux utilities.

Since [Andy] is mainly interested in tracking clouds his system only runs during daylight hours, but it can be easily changed. In fact, [Andy]’s two shell scripts are great project resources, not only because they are easily modified and well documented, but because he doesn’t make assumptions about how well one might know the command line. He also provides tips from experience; for example he has found that a 120 second interval makes for the best timelapses.

[Andy] runs his scripts on an Raspberry Pi 4, but any Linux system will do. For those who might prefer a more embedded approach, the ESP32-CAM can make a great time lapse camera with remarkably little effort.

Accessible Controller Plays Around With Modularity

April 10, 2020 by Kristina Panos 8 Comments

Video games are a great way to have some fun or blow off a little steam when real life becomes laughable. But stock controllers and other inputs are hardly one size fits all. Even if you have no physical issues, they can be too big, too small, or just plain uncomfortable to hold.

[kefcom] wrote in to give us a heads up about a modular, adaptive system he designed for anyone who is unable to operate a PS3, PS4, or PC with a standard controller. The project was inspired by Microsoft’s adaptive XBOX controller and works pretty much the same way — broken-out buttons, joysticks, and other inputs all connect to a hub that unifies them into a controller the console or computer can communicate with. The major difference is that this project is open source and can be realized much more cheaply.

If you want to give this a try, [kefcom]’s project repo has step-by-step instructions for disassembling two types of wireless controllers and converting them into hubs for modular controls. He’s looking for help with design, documentation, and finding reliable suppliers for all the parts, so let him know if you can assist.

Some players need something more accessible than just broken-out buttons and full-size joysticks. Here’s an adaptive controller that uses ridged foam rollers to actuate buttons.

Wheelbarrow Bass Drives A Sound Garden

April 2, 2020 by Kristina Panos 11 Comments

One of the best things about making music is that it’s so easy to do. There are countless ways to make interesting sounds out of nearly anything if you’re willing to experiment a little bit — just ask anyone who has ever made a guitar out of a cigar box and a broom handle.

[Vicious Squid] dug in to the fertile soil of the garden implement world and cultivated a three-string upright bass with a rich, soulful sound from a familiar workhorse — an aluminium wheelbarrow. Much of the build is made from reclaimed wood, like the solid mahogany neck from an old door frame, and a broom handle.

The bass is constructed arch-top style, meaning that the soundboard — the wood on the front with the f-holes — is a flat piece tacked to curved ribs that span the width of the ‘barrow. A broom handle sound post mounted front to back pushes vibrations from the soundboard to the aluminium body. To round out the agricultural aesthetic, [Vicious Squid] strung it with weed-whacker bass strings, which are no doubt inspired by the use of actual trimmer line.

It’s already plenty loud, but [Vicious Squid] added a piezo pickup for wheeling it into the recording studio. Slap your way past the break to hear a little ditty.

Are your instrument-building skills at the sapling stage? Start with something simpler, like a sliding rubber bandolin.

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Reverse Engineering A Ceiling Fan Remote

March 31, 2020 by Rich Hawkes 2 Comments

In the quest to automate everything in your home, you no doubt have things that aren’t made with home automation in mind. Perhaps your window AC unit, or the dimmer in your dining room. [Seb] has several ceiling fans that are controlled by remotes and wanted to connect them to his home automation system. In doing so, [Seb] gives a good overview of how to tackle this problem and how to design a PCB so he doesn’t have a breadboard lying around connected to the guts of his remote control.

There are several things [Seb] needs to figure out in order to connect his fans to Home Assistant, the home automation system he uses: He needs to determine if the circuit in the remote can be powered by 5 or 3.3 V, he needs to connect the circuit to an ESP32 board, and he needs to figure out if he can create a custom PCB that combines the circuit and the ESP32 into one. The video goes through each of these steps and shows the development of each along the way.

There’s a lot of info in the video, so it might need to be slowed down a bit to see all the details. There are some other reverse engineering of home automation gear on the site, here, or, you might want to build your own remote to control your automated devices.

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How To Try Generative Optimization At Home

March 29, 2020 by Donald Papp 29 Comments

Chairs, spokes on a wheel, bridges, and all kinds of other load-bearing objects are designed such that material is only present where it is needed. There’s a process by which the decisions about how much material to put and where is determined by computer, and illustrating this is [Adam Bender]’s short primer on how to use generative optimization in Autodesk’s Fusion 360 (which offers a variety of free licenses) using a wheel as an example.

Things start with a solid object and a definition of the structural loads expected. The computer then simulates the force (or forces) involved, and that simulation can be used to define a part that only has material where it’s really needed. The results can be oddly organic looking, and this process has been used to optimize spacebound equipment where every gram counts.

It’s far from an automated process, but it doesn’t look too difficult to navigate the tools for straightforward designs. [Adam] cautions that one should always be mindful of the method of manufacturing when designing the part’s final form, which is always good advice but especially true when making oddball shapes and curves. To see the short process in action, watch the video embedded below.

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