It all started with an 88-ton Arburg RP300 injection molding machine in the basement, and a bit of inattention. Larry Berg wanted a couple custom plastic plugs for his Garmin GPS, so he milled out a mold and ran a few…

Larry Berg and the Purple Open Passion Project

What kind of logic circuit do you see here? This logic circuit was optimised for symmetry and art. Can you see which function is implemented in this circuit? You find more about logic gates and how they work on this Wikipedia page. Check the hints below, if you get stuck.

Read more on Logic Gates Puzzle 1 — Lucky Resistor

From the Open Source Hardware Association (OSHWA) blog:

New Policy Brief on Open Hardware for Science

The Wilson Center’s Science and Technology Innovation Program has released a new policy brief advocating for government policy support of open source hardware in science. The brief looks at recent developments in government policy surrounding open hardware, highlights the unique ability of open hardware to accelerate innovation and reduce costs, and addresses implementation challenges. Download the policy brief, and read the complimentary series of articles hosted by the Journal of Open Hardware.

We’re blessed to have such a great community at Hackaday. Our tipline often overfloweth with all manner of projects and builds of all stripes. We see it all here, from beginners just starting out with their first Arduino to diehard hackers executing daringly complex builds in their downtime, and everything in between.

If you’re sitting there in the grandstands, watching in awe, you might wonder what it takes to grace these hallowed black pages. In life, nothing is guaranteed, but I’ve been specially authorised to share with you a few tips that can maximise your chances of seeing your project on Hackaday.

Read more How Best To Get Your Project On Hackaday

From the Lucky Resistor blog:

Bottle Opener for Elderly People or with Disabilities

Older people often have troubles opening plastic bottles. Also, people with gout or other disabilities lack the required strength to turn the small caps independently. The reason is the small diameter of the caps, which requires a strong grip with just two fingers.

There exist a variety of helper tools, assisting this task by increasing the leverage. A common problem with these tools is the static design. So if the manufacturer changes the size of the bottle cap, they do not grip properly anymore.

Recently, Lucky Resistor also made a beautiful design in our After Dark service.

We love the amazing projects Ken Sherriff does, from restoring vintage computers to reverse engineering chips. Hackaday writes on Ken’s latest adventure:

[Ken Sherriff] Picks Apart Mystery Chip from Twitter Photo

It’s no secret that the work of [Ken Sherriff] graces the front pages of Hackaday quite frequently. He’s back again, this time reverse engineering a comparator chip from a photo on Twitter. The mysterious chip was decapped, photographed under a microscope, and subsequently posted on the internet with an open call to figure out what it did.

[Ken] stepped up, and at first glance, it was obvious that most of the chip is unused, and there appeared to be four copies of the same circuit. After identifying resistors and the different transistor types, [Ken] found differential pairs.

Differential pairs form the heart of most op-amps, and by chaining them together, you can get a strong enough signal to treat it as a logic signal. Based on the design and materials, [Ken] estimates the chip is from the 1970s. Given that it appears to be ECL (Emitter-Coupled Logic), it could just be four comparators. But there are still a few things that don’t add up as two comparators have additional inverted outputs. Searching the part number offered few if any clues, so this will remain somewhat a mystery.

Thanks to our friends at Evil Mad Scientist for posting this beautiful cross section of a two layer purple PCB:

A peek inside a 2-layer circuit board from @oshpark .

Outtake from a photo shoot with @TubeTimeUS

Originally tweeted by Evil Mad Scientist (@EMSL) on April 24, 2021.

Inductors are not the most common component these days and variable ones seem even less common. However, with a ferrite rod and some 3D printing, [drjaynes] shows how to make your own variable inductor. You can see him show the device off in the video below.

The coil itself is just some wire, but the trick is moving the ferrite core in and out of the core. The first version used some very thick wire and produced an inductor that varied from 6 to 22 microhenrys. Switching to 22 gauge wire allowed more wire on the form. That pushed the value range to 2 to 12 millihenrys.

What can you do with an inductor? For this type of inductor, you are usually interested in resonating a capacitor either for an oscillator or a filter of some kind. You see big roller variable inductors in antenna matching circuits, but it is doubtful that these inductors would be suitable for transmitting unless it was with very low power.

Read more Make Your Own Variable Inductor — Hackaday…

From Josh Datko of Cryptotronix:

Introduction to Hardware Hacking and Reverse Engineering Trailer

Next week, Dmitry Nedospasov and I are giving a 4-day live-streamed course on Intro to Hardware Hacking and Reverse Engineering. In this video, I just quickly overview the Spearf1sh platform we built which is the basis for the class and hopefully for further hardware hacking fun.