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

September 29, 2022 by Arya Voronova 21 Comments

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.

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.

Continue reading “Urine Flow Measurement Made Accessible With UroFlow” →

Two e-readers side to side. On the left, you can see the frontal view, showing text on the e-ink screen. On the right, you can see the backside with a semi-transparent 3D-printed cover over it, and two AAA batteries inside a holder in the center.

Open Book Abridged: OSHW E-Reader Now Simplified, Pico-Driven

September 29, 2022 by Arya Voronova 17 Comments

If you ever looked for open-source e-readers, you’ve no doubt seen [Joey Castillo]’s Open Book reader, but you might not yet have seen the Abridged version he’s building around a Raspberry Pi Pico.

The Open Book project pairs a 4.2″ E-Ink screen with microprocessors we all know and love, building a hacker-friendly e-reader platform. Two years ago, this project won first place in our Adafruit Feather contest — the Feather footprint making the Open Book compatible with a wide range of MCUs, giving hackers choice on which CPU their hackable e-reader would run. Now, it’s time for a RP2040-based reboot.

This project is designed so that you can assemble it on your own after sourcing parts and PCBs. To help you in the process, the PCB itself resembles a book page – on the silkscreen, there is explanations of what each component is for, as well as information that would be useful for you while hacking on it, conveying the hardware backstory to the hacker about to dive into assembly with a soldering iron in hand. There’s simple but quite functional software to accompany this hardware, too – and, as fully open-source devices go, any missing features can be added.

Joey has recorded a 30-minute video of the Pi Pico version for us, assembling and testing the newly ordered boards, then showing the software successfully booting and operational. The Pi Pico-based revision has been greatly simplified, with a number of self-assembly aspects improved compared to previous versions – the whole process really does take less than half an hour, and he gets it done with a pretty basic soldering iron, too!

If you’re looking for updates on this revision as development goes on, following [Joey] on Twitter is your best bet. He’s no stranger to making devices around us more free and then sharing the secret sauce with all of us! During the 2021 Remoticon he showed off a drop-in replacement mainboard for the Casio F-91W wristwatch, and told us all about reverse-engineering its controller-less segment LCD — worth a listen for any hacker who’s ever wanted to bend these LCDs to their will.

Continue reading “Open Book Abridged: OSHW E-Reader Now Simplified, Pico-Driven” →

Card's author typing on the IBM PC110's keyboard, with the Pico W-based card plugged into the PCMCIA slot on the left. PC110's screen shows successful ping 8.8.8.8.8.

Pi Pico W Does PCMCIA, Gets This IBM PC110 Online

September 25, 2022 by Arya Voronova 37 Comments

Bringing modern connectivity to retro computers is an endearing field- with the simplicity of last-century hardware and software being a double-edged sword, often, you bring a powerful and tiny computer of modern age to help its great-grandparent interface with networks of today. [yyzkevin] shows us a PCMCIA WiFi card built using a Pi Pico W, talking ~~PCI~~ ISA. This card brings modern-day WiFi connectivity to his IBM PC110, without requiring a separate router set up for outdated standards that the typical PCMCIA WiFi cards are limited by.

The RP2040 is made to talk ~~PCI~~ ISA using, of course, the PIO engine. A CPLD helps with ~~PCI~~ ISA address decoding, some multiplexing, and level shifting between RP2040’s 3.3V and the PCI 5 V levels. The RP2040 software emulates a NE2000 network card, which means driver support is guaranteed on most OSes of old times, and the software integration seems seamless. The card already works for getting the PC110 online, and [yyzkevin] says he’d like to improve on it – shrink the design so that it resembles a typical PCMCIA WiFi card, tie some useful function into the Pico’s USB port, and perhaps integrate his PCMCIA SoundBlaster project into the whole package while at it.

This is a delightful project in how it achieves its goal, and a pleasant surprise for everyone who’s been observing RP2040’s PIO engine conquer interfaces typically unreachable for run-of-the-mill microcontrollers. We’ve seen Ethernet, CAN and DVI, along many others, and there’s undoubtedly more to come.

We thank [Misel] and [Arti] for sharing this with us!

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

September 25, 2022 by Arya Voronova 17 Comments

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!

Future Brings CPU Modules, And The Future Is Now

September 14, 2022 by Arya Voronova 36 Comments

Modularity is a fun topic for us. There’s something satisfying about seeing a complex system split into parts and these parts made replaceable. We often want some parts of our devices swapped, after all – for repair or upgrade purposes, and often, it’s just fun to scour eBay for laptop parts, equipping your Thinkpad with the combination of parts that fits you best. Having always been fascinated by modularity, I believe that hackers deserve to know what’s been happening on the CPU module front over the past decade.

A Youtube thumbnail showing a Thinpad in the background with "Not Garbage" written over its keyboard, and one more keyboard overlaid onto the picture with "garbage" written on that one. — This “swap your Thinkpad keyboard” video thumbnail captures a modularity-enabled sentiment many can relate to.

We’ve gotten used to swapping components in desktop PCs, given their unparalleled modularity, and it’s big news when someone tries to split a yet-monolithic concept like a phone or a laptop into modules. Sometimes, the CPU itself is put into a module. From the grandiose idea of Project Ara, to Intel’s Compute Card, to Framework laptop’s standardized motherboards, companies have been trying to capitalize on what CPU module standardization can bring them.

There’s some hobbyist-driven and hobbyist-friendly modular standards, too – the kind you can already use to wrangle a powerful layout-demanding CPU and RAM combo and place it on your simple self-designed board. I’d like to tell you about a few notable modular CPU concepts – their ideas, complexities, constraints and stories. As you work on that one ambitious project of yours – you know, the one, – it’s likely you will benefit a lot from such a standard. Or, perhaps, you’ll find it necessary to design the next standard for others to use – after all, we all know there’s never too few standards! Continue reading “Future Brings CPU Modules, And The Future Is Now” →

Git Intro For Hardware Hackers

September 12, 2022 by Arya Voronova 20 Comments

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” →

Lithium-Ion Batteries Are Your Friends

September 6, 2022 by Arya Voronova 56 Comments

Need some kind of battery for a project? You can always find a few Lithium-Ion (LiIon) batteries around! They’re in our phones, laptops, and a myriad other battery-powered things of all forms – as hackers, we will find ourselves working with them more and more. Lithium-Ion batteries are unmatched when it comes to energy capacity, ease of charging, and all the shapes and sizes you can get one in.

There’s also misconceptions about these batteries – bad advice floating around, fearmongering videos of devices ablaze, as well as mundane lack of understanding. Today, I’d like to provide a general overview of how to treat your LiIon batteries properly, making sure they serve you well long-term.

What’s A Battery? A Malleable Pile Of Cells

Lithium-Ion batteries are our friends. Now, there can’t be a proper friendship if you two don’t understand each other. Lithium-Ion batteries are tailored for human needs by the factory that produced them. As for us hackers, we’ll want to learn some things.

First thing to learn – a single LiIon “unit” is called a cell. An average laptop contains three or six Li-Ion cells, a phone will have one, a tablet will have from one to three. What we refer to as “battery” is typically one or multiple cells, together with protection circuitry, casing and a separate connector – most of the time all three of these, but not always. The typical voltage is 3.6 V or 3.7 V, with maximum voltage being 4.2 V – these are chemistry-defined, the same for most kinds of cells and almost always written on the cell. Continue reading “Lithium-Ion Batteries Are Your Friends” →