AOI By DIY

February 11, 2021 by 27 Comments

As anyone who has ever assembled a run of PCBs will tell you, quality inspection of solder joints can be a difficult process. Even under a microscope their appearances can be deceptive, and one silver blob can be perfect while its neighbour conceals a problem. The electronics industry have developed inspection tools to help, including optical inspection devices. It’s one of these that [Sina Roughani] has built, in the form of a hemispherical 3D printed dome with concentric rings of coloured LEDs mounted within it.

The principle behind this tool is as unexpected and simple as it is clever; by having different colours of light from different elevations of the dome it ensures that each different angle of the solder joint surface reflects a different colour. Thus a colour photograph shot from directly above the board allows visual inspection of the quality of the solder joints by the rainbow of colours that appears around their edges. This process can even be automated with OpenCV or similar, hence the process is referred to as Automated Optical Inspection, or AOI.

The technique is demonstrated with some pictures of a Raspberry Pi Pico, on which it shows really well the rainbow-edged solder joints and the red colour reflected from flat pads. What at first might seem like a novelty lighting effect becomes a very useful inspection tool.

PCB inspection is a subject we’ve covered before, though perhaps we don’t all have access to X-rays.

Linux Fu: Serial Untethered

February 11, 2021 by 28 Comments

Serial ports used to be everywhere. In a way, they still are since many things that appear to plug in as a USB device actually look like a serial port. The problem is that today, the world runs on the network. Sure, you can buy a terminal server that converts a serial port to an Ethernet port, but what fun is that? In this article, I’m going to show you how to stream serial ports over the network using some available Linux tools. It isn’t perfect, and it won’t work for every case, but when it works it works well.

Everything is a File, Until it Isn’t

At some point in the past, Unix — the progenitor of Linux — treated virtually everything as a file, and all files were created more or less equal. Programs didn’t care if a file was local, on the network, from a tape drive, or arriving over a named pipe.

But things started to change. Even though a serial port is just a file under Linux, it has some special attributes that let you set, for example, baud rates. Worse, some programs “know” too much about files and insist on certain naming conventions. So, in theory, you should be able to create a network socket, connect one end to a serial port and the other end to a program, and be done with it. In theory.

Continue reading “Linux Fu: Serial Untethered” →

Tiny Motors Enable Experimental Piano Performance

February 11, 2021 by 10 Comments

Just when you think you’ve seen every possible way to play the piano, [Alessandro Perini] came up with a new one. In this piece, written for the percussionist [Irene Bianco], hand-held motors become a tangible interface between composer, electronic music equipment, and the performer.

The performance involved ten small disc motors, held above the strings by a wooden frame. The motors are controlled by a Arduino Nano, which turns the motors on or off based on MIDI commands from a computer. However, the performance is not entirely automated. [Irene] wears a pair of contact microphones on her fingers, which she moves around inside the piano to capture the sounds of the strings vibrating in harmony with the motors themselves.

[Alessandro] has been kind enough to share a tutorial on how to recreate the hardware and software behind the performance for those keen to create similar work of their own. As with any musical endeavour, MIDI can always make it better. Video after the break.

Continue reading “Tiny Motors Enable Experimental Piano Performance” →

Tesla Recalls Cars With EMMC Failures, Calls Part A ‘Wear Item’

February 11, 2021 by 150 Comments

It’s a problem familiar to anyone who’s spent a decent amount of time playing with a Raspberry Pi – over time, the flash in the SD card reaches its write cycle limits, and causes a cavalcade of confusing errors before failing entirely. While flash storage is fast, compact, and mechanically reliable, it has always had a writeable lifespan much shorter than magnetic technologies.

Flash storage failures in the computer behind Tesla’s famous touch screen are causing headaches for drivers.

Of course, with proper wear levelling techniques and careful use, these issues can be mitigated successfully. The surprising thing is when a major automaker fails to implement such basic features, as was the case with several Tesla models. Due to the car’s Linux operating system logging excessively to its 8 GB eMMC storage, the flash modules have been wearing out. This leads to widespread failures in the car, typically putting it into limp mode and disabling many features controlled via the touchscreen.

With the issue affecting important subsystems such as the heater, defroster, and warning systems, the NHTSA wrote to the automaker in January requesting a recall. Tesla’s response acquiesced to this request with some consternation, downplaying the severity of the issue. Now they are claiming that the eMMC chip, ball-grid soldered to the motherboard, inaccessible without disassembling the dash, and not specifically mentioned in the owner’s manual, should be considered a “wear item”, and thus should not be subject to such scrutiny. Continue reading “Tesla Recalls Cars With EMMC Failures, Calls Part A ‘Wear Item’” →

Phishing With Morse Code

February 11, 2021 by 13 Comments

All of us have seen our share of phishing emails, but there are a lot more that get caught by secure email gateways and client filters. Threat actors are constantly coming up with new ways to get past these virtual gatekeepers. [BleepingComputer] investigated a new phishing attack that used some old tricks by hiding the malicious script tags as morse code.

The phishing attack targets Microsoft account login credentials with an HTML page posing as an Excel invoice. When opened, it asks the user to re-enter their credentials before viewing the document. Some external scripts are required to render the fake invoice and login window but would be detected if the links were included normally. Instead, the actor encoded the script links using dots and dashes, for example, “.-” equals “a”. A simple function (creatively named “decodeMorse”) is used to decode and inject the scripts when it runs in the victim’s browser.

Of course, this sort of attack is easy to avoid with the basic precautions we are all familiar with, like not opening suspicious attachments and carefully inspecting URLs. The code used in this attack is simple enough to be used in a tutorial on JavaScript arrays, but it was good enough to slip past a few large company’s filters.

Phishing attacks are probably not going to stop anytime soon, so if you’re bored, you could go phishing for phishers, or write some scripts to flood them with fake information.

Restored Dreamcast Is A SEGA Fan’s Dream Come True

February 11, 2021 by 43 Comments

[Bren Sutton] has been a long time fan of SEGA’s Dreamcast, eagerly snapping one up right around its October 1999 European release. But after years of neglect and a somewhat questionable paint job a decade or so back, he decided it was time to spruce his old friend up. He could have just cleaned the machine and been done with it, but he took the opportunity to revamp the console’s internals with both practical and cosmetic trickery.

The first step was getting the system looking a bit fresher. Removing the silver metallic paint he applied in his youth with a rattle can wasn’t going so well, so he ended up buying a broken donor console on eBay so he’d have a new shell to work with. The donor was yellowed with age, but a coating of peroxide cream and a few hours under a cheap UV light got it whitened up nicely. Now that he had a fresh new case, [Bren] turned his attention to the internal components.

Those who might be plugged into the active Dreamcast homebrew scene may already know that several upgrade modules exist for SEGA’s last home game console. One of the most popular replaces the optical drive with an SD card filled with your favorite game ISOs. You can also get a modern high efficiency power supply, as well as a board that replaces the original soldered-on clock battery with a slot that fits a CR2032. [Bren] threw them all in, ensuring several more years of gaming bliss.

But he wasn’t done yet. He also wanted to add some visual flair to his new and improved console. After some consideration, he gingerly cut the logo out of the Dreamcast’s lid, and installed an Adafruit CLUE board underneath it. With a few carefully crafted GIFs installed onto the CircuitPython-powered board, the console now has a gorgeous fully animated logo that you can see in the video after the break.

[Bren] could have really taken his console to the next level by doubling its available RAM to an eye-watering 32 MB, but considering the limited software support for that particularly bodacious modification, we’ll let it slide. Continue reading “Restored Dreamcast Is A SEGA Fan’s Dream Come True” →

A Hair-Raising Twist On Infinity Mirrors

February 10, 2021 by 6 Comments

Just when we thought we’d seen it all in the infinity mirror department, [FieldCrafting] blazed a tiny, shiny new trail with their electroplated infinity mirror hair pin. We’d sure like to stick this in our French twist. Fortunately, [FieldCrafting] provided step-by-step instructions for everything from the 3D printing to the copper electroplating to the mirror film and circuitry application.

And what tiny circuitry it is! This pin is powered by a coin cell and even has a micro slider switch to conserve it. The stick parts are a pair of knitting needles, which is a great idea — they’re pointy enough to get through hair, but not so pointy that they hurt.

[FieldCrafting] was planning to solder 1206 LEDs to copper tape and line the cavity with it, but somehow the CAD file ended up with 0603, so there wasn’t enough space for two tape traces. We think it’s probably for the better — [FieldCrafting]’s solution was to use two-conductor wire, strategically stripped, which seems a lot less fiddly than trying to keep two bare tape traces separated and passing pixies.

Don’t have enough hair for one of these? Surely you could use some handsome infinity coasters to round out that home bar setup.