Tindie

The Teensy 4.1 is famously powerful, with a 600MHz ARM Cortex-M7, a 64-bit floating point unit, gobs of flash and RAM (which are expandable!) and certain interfaces that are ideal for audio processing, like I2S and S/PDIF. This Programmable Guitar Pedal combines the intense processing power of the Teensy with a high-quality ADC and DAC audio chipset, the WM8960, to create the ultimate in customizable guitar effects pedals.

The Teensy Audio Library is a very well-written and easy-to-use audio processing library which is perfect for applications like this. The documentation includes a few examples of simple effects like Bitcrusher and Delay, and it’s amazing that each effect is only a hundred or so lines of code. There is even a GUI application to help you design and tweak the audio processing, so you can quite literally create just about any sound you can imagine. The possibilities are truly endless!

If you’re a guitar player and are willing to learn a bit about how the Teensy Audio Library works, this could become a key part of your pedal lineup. It’s designed to fit into a Hammond 1590B enclosure, a very popular enclosure for guitar pedals, so you can decorate it and make it uniquely your pedal. Check out the full listing page for all the details!

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It’s truly amazing how much power hackers have been able to squeeze out of the dual-core RP2040. Considering they are only Cortex-M0+ cores and not the more powerful M4 or M7 cores, generating signals like DVI and HDMI is simply amazing. This add-in card for the classic Apple ][ adds a digital video output which is significantly sharper and, of course, easier to use with modern displays and TVs.

It generates the video signal directly from the video RAM contents, and because it has total control, it can easily do 80-column output, alternative character sets and keyboard layouts. Because the communication is bidirectional, future expansion for the card could easily add features that modify RAM contents or snoop on the expansion bus. Already, a special firmware for the Apple 2e allows it to emulate a floppy drive!

Like a Pico, it has a USB-C connector for power and programming when not being used in the machine. Otherwise, it gets power from the Apple ][ and runs completely self-contained. The display emulates the classic Apple artifact colour look, though I’m sure it would be possible to convert the artifact colours into true, regular colour outputs — I wonder how that would look? If you’ve got an Apple ][ and don’t want to keep a classic CRT around for it, this is a great option to bring it into the 21st century.

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I2C devices are so commonplace nowadays that the hacker community has mostly coalesced around 2 connector types: JST SH and JST PH, known variously as Stemma, Qwiic, Stemma QT, Grove, etc. You can get an almost unlimited number of sensors and chip breakouts with these connectors, which can be daisy-chained for a large number of different sensors on the same bus. Well, this nifty I2C Shim for the Pico brings two JST SH connectors out for easy connection to Stemma QT/Qwiic peripherals.

The board is a nice, clean design. Staggered pads make for a tight, snug fit on the header pins coming from the Pico; however, you can also solder it directly to the Pico, or solder it to the header pins for a more secure, long-term connection. The board and connectors are slim enough that you could still mount the combination onto a PCB and solder the headers into place.

Having access to both I2C buses is a plus, as often you may want to connect two of the same sensor as many cannot have their I2C addresses reconfigured. This will allow you to do so without much hassle at all! If you use a lot of I2C peripherals, pick up a few of these and keep them with your hoard of Picos (come on, we all have a hoard of them) for quick and easy prototyping when needed!

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I’ve been looking for a nice, small, all-in-one power supply that can be powered using USB Power Delivery, and this portable DC power supply looks like a great fit for what I was imagining! It uses actual binding posts for power output, and has real knobs for adjusting power supply parameters. It has short-circuit protection and can provide up to 60W when powered from a suitable USB-C PD charger.

For something that is portable and simple to use, it doesn’t need to have the same accuracy as my Fluke benchtop power supply! It just needs to have basic 1% accuracy at least, and be good enough for quick hacks on the go or for a mobile lab bag. Most phone chargers nowadays are USB-C Power Delivery enabled, and can output at least 15V if not 20V. So being able to use something you already have on hand is a bonus!

The second USB-C port allows UART connection to the CH552 microcontroller inside. This allows you to do some basic data collection, which is a nice touch, but it also allows you to reprogram the firmware. If you want, you can spend some time carefully calibrating the supply by changing the constants in the firmware to adjust your individual unit. This option, plus the general ease of use, means it will almost certainly find use in your lab!

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Many classic Macintosh machines end up suffering from failed power supply boards. There are many different reasons for this, but primarily, these computers are now well over 35 years old and power supplies, like all components, have a rated useful life. While we’ve seen adapter boards that convert from ATX to the power connector on classic Macs, this ATX+VGA module replacement goes a step beyond and adds a Raspberry Pi Pico to give you VGA out!

It’s not clear from the description what the RCA connector on the right is for — we’re thinking possibly composite output, as audio is still handled by the motherboard. There are also two JST headers on the board, which look like they are possibly designed to drive cooling fans. In either case, we imagine documentation will improve over time, as these are hot off the press and are ready for users to put them through their paces!

It’s suggested that you could use one of the PicoATX DC supplies to make a very compact and modern replacement, and this seems like a great idea. This could also be an exceptionally useful tool for someone who often does repairs on these machines — you could easily unplug the built-in supply, connect this one with a VGA monitor pre-connected, and you can be testing with modern, reliable components in seconds.

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If you’re anything like me, any time you need 50 SMD resistors you buy 500 for the quantity discount. Same for SMD parts of all kinds! So I end up with tapes that have random amounts on them. I’m not organized enough to keep track on each reel, and I often forget which reel was used for which project. But the ReelTrack is a neat little gadget to make counting SMD parts a snap!

Keeping track of your inventory of parts can be a chore, so having a tool like this to make the job just that little bit easier is great. The slider on the back allows tapes of varying widths, and the two buttons on the front allow you to zero the count and select the pitch of the devices on the tape. Then you pull the tape through and let the machine do the counting. It has a spot for a lanyard loop, so it could be a great tool for someone working on a PCB manufacturing floor.

It’s USB-C powered, so to make it mobile, all you’d need is a small USB battery pack. As to how it actually does the counting – we can’t tell from the listing, but based on the presence of the LED in the front, we assume it’s using either the sprocket holes or just the contrast between the devices and the rest of the tape to get optical data. In any case, if you do a lot of DIY PCB assembly, it would make a great addition to your lab!

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If you’re an amateur radio enthusiast like me, you’re always keeping an eye out for new amateur radio products on Tindie! When I saw this board pop up, I was immediately interested. Interfacing radios to digital mode software like FLdigi can be a pain, but this excellent isolated USB output board eliminates all the hassle. The TARIG-Lite uses a USB audio DAC chip with isolation to allow audio from any digital mode program to pass through to your transceiver!

Simply connect the USB-C end to any device that supports USB audio (pretty much all major operating systems and Android should “just work”) and then connect the other end to your radio. You might need to wire up a custom cable, but it’s a very simple connection and only basic soldering skills are needed.

After it’s set up, just choose it as the output device and get clean, ground-loop free audio. Since it’s so small and should work with many phones and tablets, you can even take it on the go to do digital modes with your mobile rig. Bring it along on Field Day (coming up at the end of June!) and give it a test to see how far you can make digital contacts!

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If, like me, the urge to write strikes you at random times, it can be frustrating to not have the tools to get your thoughts out. And often when I feel like writing, I need to get away from my laptop and phone to eliminate distractions and just type. While there are many distraction-free writing strategies (such as using a typewriter!), there are many benefits of using a digital micro journal. This selection of multiple DIY Micro Journal kits gives you not only a great tool to help encourage spontaneous writing, but also allows you to easily transfer your text to other digital devices if you want.

On top of those benefits, you can also make the kit uniquely yours. The process of assembling the journal will give you many opportunities to modify and personalize it to suit your tastes. You could paint the shell, add stickers, change parts of the design like the screen or keyswitches, and generally create a unique piece that is itself an expression of your creativity!

Un Kyu Lee offers three different styles of kits, which range in price and size. They are also available pre-assembled if you just want a complete, well-built tool to work with. Almost all the parts needed are included; you just need to provide a battery, SD card, and keyswitches compatible with the MX Cherry footprint. Custom colours are available, and each version has its own build guide and quick start guide that’ll have you up and writing in no time.

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The Small Computer System Interface or SCSI (pronounced skuz-ee) was a very common method of connecting hard drives, CD-ROMs, magneto-optical disks and many other peripherals to computers. Originating in 1981, it lives on today as Serial-Attached-SCSI or SAS. But there are many vintage machines out there that depend on SCSI devices to function, and working peripherals will only get more difficult to acquire. So the SCSIknife SCA aims to help bridge that gap by emulating essentially any type of storage device, from hard drives to tape backups.

The firmware is based on the ZuluSCSI Pico firmware, an open-source firmware for interacting with SCSI devices. Then the SCSIknife adds on a very neatly laid-out board to run the firmware and hold SD and microSD cards. The design makes it very easy to connect a SCSI cable and has been tested with a huge number of vintage machines, from the very high-end and rare (a Symbolics LISP Machine) to the widely known and loved (the BBC Micro/Master, Commodore Amiga, Apple IIgs, etc.).

The SCSIknife is made by Antoine Bercovici — yes, that Antoine — and so we know it will be a reliable and easy-to-use solution because it will have been tested with a lot of real hardware! We are looking forward to seeing this device used to rescue and restore all sorts of interesting computers from the 1980s onward.

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Isolating digital buses can help with a lot of different issues. One of the biggest issues is when you want to connect to a circuit that is part of a high-voltage project, e.g., a Tesla coil or even just vacuum tube systems like Nixies. This 4-channel digital isolator (3 out, 1 in) is a well-designed little board that also provides compatibility with both 3.3v and 5V systems.

Having an isolation barrier protects your low-voltage circuitry against transients and differing ground potentials, as well as protecting against high-voltage shorting to a signal pin. It’s much easier to replace an isolator chip than your expensive FPGA or SoC. This board is based around the TI ISOW7841, which is a great choice for this project. It is designed for a working isolation of 1000Vrms with transients of up to 7kV! There are other chips in this line that have differing numbers of in/out channels, as well as different working isolation voltages; they are mostly drop-in compatible (be sure to check the datasheet!).

These can also be used when connecting a USB logic analyzer to a high-voltage system. While you can unplug a laptop to get isolation, sometimes this isn’t feasible, and of course, PCs must be plugged in to work. You can easily damage circuitry if the ground potentials are different and there is no isolation barrier in place — so pick one of these up and keep it in the toolbox! You’ll be glad you have one when the time comes.

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