front and back of the Jolly Wrencher SAO

Jolly Wrencher SAO, And How KiCad 6 Made It Easy

If you plan to attend Supercon or some other hacker conference, know that you’re going to get a badge with a SAO (Simple Add-On) connector, a 4-pin or 6-pin connector that you can plug an addon board onto. There’s myriads of SAOs to choose from, and if you ever felt like your choice paralysis wasn’t intense enough, now you have the option of getting a Jolly Wrencher SAO board!

This board gives you an SMD prototyping space, with 1.27mm (0.05″ pitch) pads, suitable for many passive components, ICs and even modules like the ESP32 WROOM. Those pads are diagonally interspersed with ground-fill-connected pads – if you want to bodge something on the spot, you don’t need to pull separate GND wires. Given the Supercon badge specifics, the SAO-standard SDA and SCL pins have RX and TX labels as well. For bonus points, the eyes are transparent, with LED footprints behind them – it’s my first time designing a PCB where the LED shines through the FR4, and I hope that the aesthetics work out!

This design is open with gerber files available for download, so if you thought of making a quick PCB order, I’m giving you one more .zip file to add to it. Otherwise, it’s possible that you will find a Wrencher board lying around at Supercon! Now, I’d like to tell you how KiCad 6 made it super easy to design this PCB – after all, there’s never enough SAOs, and it’s quite likely you’ll want to design your own special SAO, too.

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A sliced digital file of a marker light enclosure. Background is a white and grey grid and object itself is a series of print path lines in red, orange, and green.

3D Printing Hard-To-Find Vintage Vehicle Parts

When I was growing up, my dad and I restored classic cars. Combing junkyards for the pieces we needed was a mixture of interesting and frustrating since there was always something you couldn’t find no matter how long you looked. [Emily Velasco] was frustrated by the high price of parts even when she was able to find them, so she decided to print them herself. She wrote an excellent tutorial about designing and 3D printing replica parts if you find yourself in a similar situation.

All four marker lights on [Velasco]’s 1982 Toyota pickup were on their way to plastic dust, and a full set would run her $160. Instead of shelling out a ton of cash for some tiny parts, she set out to replicate the marker lamps with her 3D printer. Using a cheap marker lamp replacement for a more popular model of pickup as a template, she was able to replace her marker lamps at a fraction of the cost of the options she found online. Continue reading “3D Printing Hard-To-Find Vintage Vehicle Parts”

Git Your PCBs Online

Last time, I’ve shown you how to create a local Git repository around your PCB project. That alone provides you with local backups, helping you never lose the changes you make to your files, and always be able to review the history of your project as it developed.

However, an even more significant part of Git’s usefulness is the ability to upload our creations to one of the various online Git repository hosting services, and keep it up to date at all times with a single shell command. I’d like to show you how to upload your project to GitHub and GitLab, in particular!

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Front of PCB for "SMT Garden" with glowing LEDs

Surface Mount Soldering Practice For Budding Electrical Engineers

Electronics components are steadily moving away from through hole parts to using surface mount technology (SMT) exclusively. While the small size of the SMT components can be intimidating, with a little practice, soldering can come pretty naturally. To help folks get over their fear of soldering small parts, [Alpenglow Industries] have created a charming board to practice SMT soldering skills on.

Back of "SMT Garden" PCB with only the 555 timer chips and inverter chip populated

[Alpenglow Industries] board, called the “SMT Garden”, combines a variety of SMT sizes ranging from 0402 to 1206 with beautiful PCB artwork to highlight the variety of LEDs on board. [Alpenglow Industries] provides detailed instructions on the various aspects of SMT soldering including what the terminology is and providing various techniques to help in soldering. The boards have practice “stalks” of surface mount component pads, so that folks can practice on columns of similarly sized SMT components to perfect their technique. The training stalks themselves aren’t functional but are there to provide practice for when folks feel comfortable soldering the LEDs, 555 timer and inverter chips to make the board functional.

[Alpenglow Industries] have provided all the KiCAD project files, gerbers and schematics available online. SMT soldering is more accessible than ever and when you can even use your phone as a microscope, it’s a good excuse to try it out, if you haven’t already.

picture showing the re-built scale with an extra blue box with electronics on the bottom of it. on the scale, there's a transparent food-grade plastic glass with measurement marks on the side.

Urine Flow Measurement Made Accessible With UroFlow

If you’re dealing with a chronic illness, the ability to continuously monitor your symptoms is indispensable, helping you gain valuable insights into what makes your body tick – or, rather, mis-tick. However, for many illnesses, you need specialized equipment to monitor them, and it tends to be that you can only visit your doctor every so often. Thankfully, we hackers can figure out ways to monitor our conditions on our own. With a condition called BPH (Benign Prostate Hyperplasia), one of the ways to monitor it is taking measurements of urinary flow rate. Being able to take these measurements at home provides better insights, and, having found flow rate measurement devices to be prohibitively expensive to even rent, [Jerry Smith] set out to build his own.

This build is truly designed to be reproducible for anyone who needs such a device. Jerry has intricately documented the project and its inner workings – the 31-page document contains full build instructions, BOM for ordering, PCB description and pinout diagrams, calibration and validation instructions, and even software flowcharts; the GitHub repo has everything else you might need. We’re pleasantly surprised – this amount of documentation isn’t typically seen in hacker projects, and is even more valuable considering that this is a medical device that other hackers in need will want to reproduce.

Graph titled "Flow", with X axis saying "seconds" and Y axis saying "ml/Sec". There's differently colored plots on the graph, each apparently corresponding to a different measurement.For the hardware, [Jerry] took a small digital scale of a certain model and reused its load cell-based weighing mechanism using an HX711 amplifier, replacing the screen and adding an extra box for control electronics. With an Arduino MKR1010 as brains of the operation, the hardware’s there to log flow data, initially recorded onto the SD card, with WiFi connectivity to transfer the data to a computer for plotting; a DS3234 RTC breakout helps keep track of the time, and a custom PCB ties all of these together. All of these things are easy to put together, in no small part due to the extensive instructions provided.

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On the left, an image of a COB on the multimeter's PCB. On the right, a QFP IC soldered to the spot where a COB used to be, with pieces of magnet wire making connections from the QFP's pins to the PCB tracks.

Epoxy Blob Excised Out Of Broken Multimeter, Replaced With A QFP

The black blobs on cheap PCBs haunt those of us with a habit of taking things apart when they fail. There’s no part number to look up, no pinout to probe, and if magic smoke is released from the epoxy-buried silicon, the entire PCB is toast. That’s why it matters that [Throbscottle] shared his journey of repairing a vintage multimeter whose epoxy-covered single-chip-multimeter ICL7106 heart developed an internal reference fault. When a multimeter’s internal voltage reference goes, the meter naturally becomes useless. Cheaper multimeters, we bin, but this one arguably was worth reviving.

[Throbscottle] doesn’t just show what he accomplished, he also demonstrates exactly how he went through the process, in a way that we can learn to repeat it if ever needed. Instructions on removing the epoxy coating, isolating IC pins from shorting to newly uncovered tracks, matching pinouts between the COB (Chip On Board, the epoxy-covered silicon) and the QFP packages, carefully attaching wires to the board from the QFP’s legs, then checking the connections – he went out of his way to make the trick of this repair accessible to us. The Instructables UI doesn’t make it obvious, but there’s a large number of high-quality pictures for each step, too.

The multimeter measures once again and is back in [Throbscottle]’s arsenal. He’s got a prolific history of sharing his methods with hackers – as far back as 2011, we’ve covered his guide on reverse-engineering PCBs, a skillset that no doubt made this repair possible. This hack, in turn proves to us that, even when facing the void of an epoxy blob, we have a shot at repairing the thing. If you wonder why these black blobs plague all the cheap devices, here’s an intro.

We thank [electronoob] for sharing this with us!

Git Intro For Hardware Hackers

Git is a wonderful tool that can multiply your project’s impact, or make your project easier to manage by an order of magnitude. Some of us hackers don’t yet know how to use command-line Git, but a relatable example of why a certain tool would be useful might be a good start. Today, I’d like to give you a Git crash course – showing you why and how to put a KiCad PCB into a Git repository, later to be shared with the world.

KiCad works wonderfully with Git. The schematic and PCB files of KiCad are human-readable, especially when compared to other PCB file formats. KiCad creates different files for different purposes, each of them with a well-defined role, and you can make sense of every file in your project folder. What’s more, you can even modify KiCad files in a text editor! This is exactly the kind of use case that Git fits like a glove.

Not Just For Software Developers

What’s Git about, then? Fundamentally, Git is a tool that helps you keep track of code changes in a project, and share these changes with each other. Intended for Linux kernel development as its first target, this is what it’s been designed for, but it’s flexibility extends far beyond software projects. We hardware hackers can make use of it in a variety of ways – we can store PCB and other design software files, blog articles, project documentation, personal notes, configuration files and whatever else that even vaguely fits the Git modus operandi. Continue reading “Git Intro For Hardware Hackers”