hardware

1825 Articles

Make Your Own Pot And Encoder Knobs, Without Reinventing Them

January 14, 2023 by 10 Comments

Rotary potentiometers, switches, and encoders all share a basic design: adjustment is done via a shaft onto which a knob is attached, and knobs are sold separately. That doesn’t mean one knob fits all; there are actually a few different standards. But just because knobs are inexpensive and easily obtained doesn’t mean it’s not worth making your own.

A simple and effective indicator can be easily printed in a contrasting color.

Why bother 3D printing your own knobs instead of buying them? For one thing, making them means one can rest assured that every knob matches aesthetically. The ability to add custom or nonstandard markings are another bonus. Finally, there’s no need to re-invent the wheel, because [Tommy]’s guide to making your own knobs has it all figured out, with the OpenSCAD script to match.

By default, [Tommy]’s script will generate a knob with three shims (for interfacing to a splined shaft) when pot_knob(); is called. The number of shims can be adjusted by modifying potKnobDefaultShimCount. To give the knob a flat side (to interface with D-shafts), change flatted = false to flatted = true. And for adding a screw insert suitable for a set screw? Change tightenerDiameter = 0 from zero to the diameter desired.

The script is quite comprehensive and has sensible defaults, but it does require a bit of knowledge about OpenSCAD itself to use effectively. We have covered the basics of OpenSCAD in the past, and if you’re ready for a resource that will help you truly master it, here’s where to look.

Release Less Magic Smoke, With A Bulb Limiter

January 8, 2023 by 29 Comments

As electronics have moved lower in voltage, it’s perhaps less common to work on live-mains equipment. Thus particularly among younger hardware hackers it sometimes seems as though such work is viewed as so dangerous as to be only for the foolhardy. In practice it remains safe, so long as appropriate precautions are taken and a few pieces of useful safety equipment are present. One of those mains bench essentials is something less common in 2022, a mains current limiter using a set of switched incandescent light bulbs. [Donna LaRocco] shares a modern take on the idea, incorporating a digital mains voltmeter.

The idea is that a mains device under test is connected in series with a light bulb of a suitable wattage to let through enough current to run the device in normal operation, but to light up and bring down the voltage if the device draws too much. It’s an extremely simple but effective tool. Traditionally these are built using household electrical fittings on a board, and this one is no exception. The voltmeter comes from the RV market where voltage drop is an issue, no doubt giving European readers a chance to chuckle with their 230 V outlets.

If mains safety needs your attention, it’s a subject we’ve addressed in the past.

A notated illustration showing how a mycelial network may be functionalized as a PCB substrate. The process starts with Cu vapor deposition onto the network followed by Au either by more vapor deposition or electrodeposition. Traces are then cut via laser ablation.

MycelioTronics: Biodegradable Electronics Substrates From Fungi

January 6, 2023 by 12 Comments

E-waste is one of the main unfortunate consequences of the widespread adoption of electronic devices, and there are various efforts to stem the flow of this pernicious trash. One new approach from researchers at the Johannes Kepler University in Austria is to replace the substrate in electronics with a material made from mycelium skins.

Maintaining performance of ICs and other electronic components in a device while making them biodegradable or recyclable has proved difficult so far. The substrate is the second largest contributor (~37% by weight) to the e-waste equation, so replacing it with a more biodegradable solution would still be a major step toward a circular economy.

To functionalize the mycelial network as a PCB substrate, the network is subjected to Physical Vapor Deposition of copper followed by deposition of gold either by more PVD or electrodeposition. Traces are then cut via laser ablation. The resulting substrate is flexible and can withstand over 2000 bending cycles, which may prove useful in flexible electronics applications.

If you’re looking for more fun with fungi, check out these mycelia bricks, this fungus sound absorber, or this mycellium-inspired mesh network.

KiCad 2022 Year End Recap

KiCad 2022 End-of-Year Recap And 7.0 Preview

December 31, 2022 by 22 Comments

[Chris Gammell] moderated the KiCad 2022 End-of-Year Recap with several KiCad developers and librarians. They reviewed what’s been bubbling up in the nightly KiCad 6 builds, what we can expect from KiCad 7, and even answered some questions from the user community. Over the course of 2022, the KiCad project has grown both its development team and library team. The project even has a preliminary support commitment from the CERN Drawing Office!

Improvements to the KiCad Schematic Editor include smart wire dragging that simplifies moving components around within schematic diagrams. Components selected in the schematic now remain selected while switching to the PCB Editor. Internal documentation of schematics has advanced with support for fonts, embedded graphics, and the inclusion of hypertext links to datasheets and other reference materials. New features for PDF generation offer interactive files and links between sheets.

A new search panel within the KiCad PCB Editor supports finding components by footprint, net, or text search. A property panel allows common properties to be edited across multiple selected items. While a full-blown auto-router remains outside of the scope for KiCad, “push and shove” routing is faster and easier. An “attempt to finish” feature routes a quick connection for the currently selected trace, and “pack and move” positions all selected footprints into proximity to simplify placing them as neighbors within the board layout.

The KiCad PCB Editor also adds support for the use of fonts and inverted “knockout text” which even works on copper zones. Bitmap graphics can be imported and scaled beneath layout work as reference illustrations. Private footprint layers can be used to place extra documentation within footprints. The design rule checker (DRC) now can catch more layout issues, especially those that may impact manufacturability.

These are just a sampling of the impressive improvements we can expect with KiCad 7.0. There are also additions to circuit simulation and modeling features, a new command line interface for script-based automation, ARM64 support for KiCad running on Apple silicon, and a huge number of additions to the default library including symbols, footprints, and 3D Viewer models.

The KiCad team suggests several ways to support the project. There are always needs for additional developers and librarians. Financial contributions can be made at kicad.org. As users, we can run the nightly builds, try to break them, and give feedback in the form of detailed bug reports. Community testing will help make KiCad 7.0 as solid as possible. The project team is also seeking open hardware projects to include with KiCad 7.0 as demos.  For example, the StickHub project was included with KiCad 6.0 as a demo.

The official release of KiCad 7.0 is currently scheduled for January 31, 2023. While we wait, let’s flashback to our January 2022 presentation of what features made it into the KiCad 6.0 release.

Continue reading “KiCad 2022 End-of-Year Recap And 7.0 Preview” →

A beige keyboard with blue and grey keys sits on a colorful deskmat atop a wooden desk. A small box with a round Touch ID button sits next to the keyboard.

Standalone Touch ID For Your Desktop Mac

December 26, 2022 by 1 Comment

With the proliferation of biometric access to mobile devices, entering a password on your desktop can feel so passé. [Snazzy Labs] decided to fix this problem for his Mac by liberating the Touch ID from a new Apple keyboard.

When Apple introduced its own silicon for its desktops, it also revealed desktop keyboards that included their Touch ID fingerprint reader system. Fingerprint access to your computer is handy, but not everyone is a fan of the typing experience on Apple keyboards. Wanting to avoid taping a keyboard under his desk, [Snazzy Labs] pulled the logic board from the keyboard and designed a new 3D printed enclosure for the Touch ID button and logic board so that the fingerprint reader could reside close to where the users hands actually are.

One interesting detail discovered was the significantly different logic boards between the standard and numpad-containing variants. The final enclosure designs feature both wireless and wired versions for both the standard and numpad logic boards if you should choose to build one of your own. We’re interested to see if someone can take this the next step and use the logic board to wire up a custom mechanical keyboard with Touch ID.

If [Snazzy Labs] seems familiar, you may recognize him from their Mac Mini Mini. If you’re more in the mood to take your security to the extreme, check out this Four Factor Biometric Lockbox that includes its own fingerprint reader.

Continue reading “Standalone Touch ID For Your Desktop Mac” →

A radio with a white front grate and wood edges sits on a grey surface. Next to the radio are small white disks with colorful edges reminicient of microdisc-sized records. A yellow-ringed disk sits on the radio. The handwritten title says, "Summer of 2011; Holidays in Barcelona"

Spotify Player Brings Back Physical Media

December 24, 2022 by 21 Comments

Digital music has made keeping all your tunes with you a lot more convenient, but have we lost something with dematerialization? [Jordi Parra] felt that there was something lacking with the digital music experience and designed a Spotify player with a tactile interface.

Specific playlists are selected via small RFID tags that look like a cross between a MiniDisc and a vinyl record. As this is a prototype, an Arduino reads the RFID tag, but needs a computer to actually play the Spotify playlist. Future iterations could include an integrated speaker and run libspotify to create a self-contained device.

While there is still work to do for a fully seamless experience, we love the details in the industrial design of this project. Clean simple lines and a combination of wood and more modern materials make this feel like a timeless piece of tech. Definitely check out the full photo gallery including shots of the really impressive packaging.

Want more digital music with a tactile interface? Check out this MP3 Player Shelf or a Simple Internet Radio Transplant.

A scan (x-ray?) of a human skull. Electrodes trace around the skull and are attached to the brain. These implants are for reducing Parkinson's tremors.

What Happens When Implants Become Abandonware?

December 16, 2022 by 32 Comments

You’ve probably had a company not support one of your devices as long as you’d like, whether it was a smart speaker or a phone, but what happens if you have a medical implant that is no longer supported? [Liam Drew] did a deep dive on what the failure of several neurotechnology startups means for the patients using their devices.

Recent advances in electronics and neurology have led to new treatments for neurological problems with implantable devices like the Autonomic Technologies (ATI) implant for managing cluster headaches. Now that the company has gone out of business, users are left on their own trying to hack the device to increase its lifespan or turning back to pharmaceuticals that don’t do the job as well as tapping directly into the nervous system. Since removing defunct implants is expensive (up to $40k!) and includes the usual list of risks for surgery, many patients have opted to keep their nonfunctional implants. Continue reading “What Happens When Implants Become Abandonware?” →