A sequence of pictures with arrows between each other. This picture shows a Wokwi (Fritzing-like) diagram with logic gates, going to a chip shot, going to a panel of chipsGA footprint on a KiCad PCB render with DIP switches and LEDs around the breakout. Under the sequence, it says: "Tiny Tapeout! Demystifying microchip design and manufacture"

Design Your Own Chip With TinyTapeout

When hackers found and developed ways to order PCBs on the cheap, it revolutionized the way we create. Accessible 3D printing brought us entire new areas to create things. [Matt Venn] is one of the people at the forefront of hackers designing our own silicon, and we’ve covered plenty of his research over the years. His latest effort to involve the hacker community, TinyTapeout, makes chip design accessible to newcomers – the bar is as low as arranging logic gates on a web browser page.

Six chip shots shown, with various densities of gates being used - some use a little, and some use a the entire area given.
Just six of the designs submitted, with varying complexity

For this, [Matt] worked with people like [Uri Shaked] of Wokwi fame, [Sylvain “tnt” Munaut], [jix], and a few others. Together, they created all the tooling necessary, and most importantly, a pipeline where your logic gate-based design in Wokwi gets compiled into a block ready to be put into silicon, with even simulations and compile-time verification for common mistakes. As a result, the design process is remarkably straightforward, to the point where a 9-year-old kid can do it. If you wanted, you could submit your Verilog, too!

The first round of TinyTapeout had a deadline in the first days of September and brought 152 entries together – just in time for an Efabless shuttle submission. All of these designs were put on a single instance of a chip, that will be fabbed in quantity, tested, soldered onto breakouts, and mailed out to individual participants. In this way, everyone will be getting everyone’s design, but thanks to the on-chip muxing hardware, they’re able to switch between designs using on-breakout DIP switches.

More after the break…

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The dosing spoon shown, with many round openings for medication pellets to go into

Medicine Dosing Spoon Discontinued, Made 3D Printable Instead

[Gregor Herz] caught wind of a problem that neuropediatric clinics in Germany have been facing recently. Orfiril, a seizure-preventing medication used in those clinics for treating children, is normally prescribed to adults, and the usual dosages are too high for kids. Orfiril comes in regular pill-shaped capsules, each capsule containing a bunch of small medication-soaked pellets, and you only need a certain amount of these pellets if you want to achieve a lower dose.

An Orfiril medication bottle is shown, with an Orfiril pill capsule next to it, showing the small pellets inside. Another pill capsule has been disassembled, with the pellets inside a teaspoon.It used to be that you could get a special spoon helping you to get a proper dosage — but sadly, the original supplier has quit making these. So, our hacker designed a 3D printable model instead.

[Gregor] tells us that a lot of clinics in Germany are facing this exact issue right now, so sharing this model may mean that more hospitals can work around the supply issue. Provided a friendly hobbyist has food-grade 3D printing conditions available, anyway. He tells about some suitable filaments models you can buy, as well as research on food-grade printing requirements — a topic we’ve talked about in detail, and just this month have seen someone revisit with reassuring results. Are you interested in printing some of these? If so, there might be a clinic nearby that’d be thankful.

We’ve seen a surge of 3D printing for medical uses two years ago, back when supply chain issues had doctors face PPE shortages, and some critical parts for equipment were in short supply. Before that, we’d sometimes see medical purpose 3D printing done in dire circumstances, when no other choices were available. Now 3D printing of medical devices is more accepted, and we can’t wait for more research and hacking on this front!

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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Lithium-Ion Battery Circuitry Is Simple

By now, we’ve gone through LiIon handling basics and mechanics. When it comes to designing your circuit around a LiIon battery, I believe you could benefit from a cookbook with direct suggestions, too. Here, I’d like to give you a collection of LiIon recipes that worked well for me over the years.

I will be talking about single-series (1sXp) cell configurations, for a simple reason – multiple-series configurations are not something I consider myself as having worked extensively with. The single-series configurations alone will result in a fairly extensive writeup, but for those savvy in LiIon handling, I invite you to share your tips, tricks and observations in the comment section – last time, we had a fair few interesting points brought up!

The Friendly Neighborhood Charger

There’s a whole bunch of ways to charge the cells you’ve just added to your device – a wide variety of charger ICs and other solutions are at your disposal. I’d like to focus on one specific module that I believe it’s important you know more about.

You likely have seen the blue TP4056 boards around – they’re cheap and you’re one Aliexpress order away from owning a bunch, with a dozen boards going for only a few bucks. The TP4056 is a LiIon charger IC able to top up your cells at rate of up to 1 A. Many TP4056 boards have a protection circuit built in, which means that such a board can protect your LiIon cell from the external world, too. This board itself can be treated as a module; for over half a decade now, the PCB footprint has stayed the same, to the point where you can add a TP4056 board footprint onto your own PCBs if you need LiIon charging and protection. I do that a lot – it’s way easier, and even cheaper, than soldering the TP4056 and all its support components. Here’s a KiCad footprint if you’d like to do that too.

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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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Watch on the wrist, with all the sensors facing the camera. There's a lot of them, and a lot of wires of all kinds tying everything together.

2022 Cyberdeck Contest: IP00-Minus, A Daring Wearable

[Rob]’s IP00-Minus watch stands out on the Cyberdeck Contest project list page; it’s clear he decided to go a different path than most other hackers, and we can certainly see the advantages. For example, if there’s no case, there’s no need to redesign it each time you want to add a module — and [Rob] has added many, many modules to this watch.

Picking between regular LCD, memory LCD, and OLED displays can be a tricky decision to make when planning out your gadget, so he just added all three. The CircuitPython firmware initially attempted to resist the trio, but was eventually defeated through patching. Jokes aside, we can almost feel the joy that [Rob] must have felt after having put this watch on for the first time, and this project has some serious creative potential for a hacker.

Watch on the wrist, showing the wrist straps and how the watch sits on the arm.[Rob] has been focusing on day-to-day usability first and foremost, with pleasantly clicky encoders, impeccable performance of its watch duty, unparalleled expandability, and comfortable wrist fit — it provides a feeling no commercial wearable could bring.

Out of the myriad of sensors, the air quality sensor has been the most useful so far, letting him know when to open a window or leave a particularly crowded place. The ESP32-S3 powered watch has been quite a playground for [Rob]’s software experiments, and given the sheer variety of hardware attached, we’re sure it will bring unexpected synergy-driven ideas. Plus, it’s no doubt a great conversation starter in nerd and non-nerd circles alike.

Good things happen when you give hackers a wrist-worn watch full of sensors, whether it’s a particularly impressive event badge, a modified firmware for an open source smartwatch, or a custom piece that pushes the envelope of DIY hardware.

The assembled switch PCB in the palm of its creator's hand

TTP223 Brings Simple Touch Controls To A LED Lamp

You can buy small modules with capacitive touch detection ICs — most often it’s the TTP223, a single-button capacitive model with configurable output modes. These are designed to pair with a microcontroller or some simple logic-level input, but [Alain Mauer] wanted was to bring touch control to a simple LED strip. Not to be set deterred, he’s put together a simple TTP223-based switch board.

Initially, he made a prototype using one of the regular TTP223 boards as a module, but then transferred the full schematic onto a single PCB. The final board uses an NPN transistor capable of handling up to 3 amps to do the switching job, and Zener-based regulation to provide 5 V for the TTP223 itself from the 12 V input. [Alain] shares the schematic, as well as BOM together with Gerber files for a 2×3 panel in case you’re interested in adding a few of these handy boards to your parts bin.

The TTP223 is a ubiquitous and quite capable chip – we’ve seen it used for building a mouse with low actuation force buttons, a soft power switch, and even a UV-sensing talisman that’s equal parts miniature electronics and fascinating metalwork.

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