Generative Sequencer

Nick Monk (Snowsh) created a monster PCB known simply as “The Machine.” The Teensy 4.1-based behemoth is a generative synth with additional capabilities via expansion modules.

A combination of WS2812 RGB LEDs and OLED displays form the UI, with copious potentiometers and buttons providing the interface. While not much more detail is known about the impressive device, the below video and associated playlist give an idea of its capabilities.

Zoom Phone

Interaction designer Dice Yukita to explore new — or rather old — paradigms for drudgingly routinized daily work from home meetings with his Zoom Phone.

By hacking a commodity USB headset into a traditional telephone handset, plus incorporating the HID capabilities of the Teensy 4.0 and some Swiftbar scripting, Dice was able to realize the classic interactions of telephone usage, like picking up the phone, covering the mic, and having to sandwich the phone between your neck and shoulder in order to accommodate other tasks.

The project builds on his earlier Teensy-based Bidirectional Physical Zoom Mute Button, with the curious “bonus” that upon muting yourself by replacing the handset on the phone’s base, you are also unable to hear other meeting participants, as demonstrated in this video demo.

JawsFX – Guitar Pedal With Shark Proximity Looping

What do you get for the Jaws fan who has everything? Pio’s (HexeguitarDIY) custom Jaws-themed guitar effects pedal with “shark proximity” looping feature! Like the classic movie, result is terrifyingly impressive!

A custom PCB houses an NXP SGTL5000 audio codec and filters, plus a TI CD4053 MUX/DEMUX for bypass, with a second board adding analog pass-through, wet/dry audio mixer, relay-based stereo bypass, and four reverse-mount status indication RGB LEDs driven by an NXP PCA9685.

A Hammond 1590S enclosure with custom graphics wraps it all up in a beautiful package.

The software allows the looping of audio from the film, with increasing “shark proximity” intensity, as well as playing of quotes from the movie, and a stereo plate reverb on the guitar path. An automatic lowpass ducker helps keep the focus on the incoming guitar so that the background sounds stay in the background.

Check out a demo in the video below, and if you want a really annoying earworm in your head for the rest of the day, click on the hidden easter egg demo below that … !

Toslink Delayer To Sync Audio

Andy Haus ran into an annoying issue with his Amazon Echo Link music streaming devices: despite being connected to their respective host speaker systems via TOSLINK optical cables, one was lagging behind the other, meaning music played over both was out of sync.

Since the ~200ms delay was being caused by internal processing in one of the systems itself, and Amazon provides no adjustment facility, Andy designed a custom PCB for the Teensy 4.0 and took matters into his own hands.

The solution takes in S/PDIF from the Echo Link using a DLT1150 optical fiber receiver, then delays it by an adjustable amount (up to 750ms), before outputting it again over TOSLINK to the speaker system via another DLT1150. The delay value is stored in EPROM in order to maintain the configuration in the event of power loss. An SSD1306 OLED display shows status, including CPU usage, which hovers around 30% when underclocked at 150MHz. Source and schematics can be found in the GitHub repo.

Modernized FX-300 Jackal TV/Radio

Tom Granger picked up a couple of FX-300s in a state where they weren’t actually doing as much as turning on, which was the starting point for an incredible modernization.

Sony’s 1978 FX-300 Jackal was somewhat of a technological marvel: AM/FM radio, cassette player/recorder, and mini CRT TV, all in one unit! But as the practicality of each of these features dwindles in the modern era, you end up with a rad-looking box that doesn’t actually do much.

Starting with a Teensy 4.0 and Audio Adaptor Board, Tom restored much of the original functionality, including details like the original buttons and VU meter. A 3.2″ ILI9341 TFT LCD replaces the original CRT, and an RDA5807M restores FM radio capabilities. A PAM8403 3W class-D audio amplifier brings the noise, and a HiLetgo M18 adds Bluetooth audio. Relive the journey in Tom’s original thread.

Giant Darth Vader Minifig

Last time we saw The Sketchy Maker on the PJRC blog, it was in the form of a giant 3d-printed LEGO Luke Skywalker, in celebration of Star Wars day. Now they’re back, but have taken a turn to the dark side, with a giant Darth Vader minifigure.

The more sinister effigy follows the same formula as the previous project, with a servo-powered arm, WS2812B-enhanced light saber, and a speaker for sound effects, all driven by our Prop Shield. Just like last time, the models were displayed publicly for the local community to enjoy, and thankfully avoided any dodgy Scottish weather and made it back safely to the shelf after their exhibition.

Vimana – Multi-track MIDI Step Sequencer

After four years in development, Guilherme Martins has released Vimana, a multi-track MIDI step sequencer. Vimana is designed to be open and flexible in terms of software and UI.

Vimana features 16 tracks, with a main clock and division/multiplication per track. Step parameters include pitch, velocity, gate, retrigger, chord, inversions and sustain. Play modes range from the expected “forward” to the interesting “pendulum” to the shocking “drunk!”

A built in quantizer features various predefined scales plus the possibility to define custom, and a Euclidean Generator adds complex generative beats. Check out the video below for a walkthrough of its features!

iSCSI Virtual Disk

Flok works with big, expensive IBM iSCSI (Internet Small Computer System Interface) boxes, so the thought occurred: what about the opposite extreme with a microcontroller and SD card? This experiment on Teensy and other boards yielded interesting benchmark results.

Usually benchmarks measure performance of 1 subsysten. But iSCSI requires simultaneous performance from networking and storage systems. Even if each can perform well on its own, what matters is how well they perform when used together.

Based on a Teensy 4.1 with Ethernet, the system yields speeds of up to 6MB/s while reading the SD card, significantly faster than other widely used microcontrollers as shown in the results below.

The device can be used as a SAN (Storage Area Network) by a remotely-connected PC via iSCSI, allowing, for example, the booting of a VMWare cluster from a SD card. Of course a microcontroller and SD card aren’t practical for real-world SAN usage. This project is really only useful as an academic exercise and way to benchmark the relative performance of microcontroller platforms when used with a demanding application which requires simultaneous networking and storage performance.

More information can be found on the project’s web page, with source available on GitHub.

Soft Breakout Board and Touch Reactive Fabric Art

Salil Parekh has been using Teensy LC for e-textile projects, but found it difficult to use while testing and debugging due to its small size, which gave birth to the Soft Breakout Board for Teensy LC.

Similar to a regular breakout board, the Soft Breakout Board brings all of the Teensy pins out for easy access, but rather than an FR-4 PCB, is made of denim.

This breakout was then used to develop this touch reactive art piece.

Magnet wire connects the real pins to large snaps in place of vias, which can then easily be connected to with alligator clips during prototyping. Copper tape can be affixed to the snaps for a more robust solution, then removed and rearranged in subsequent projects. See it in action on Salil’s blog.