Blog Posts

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.

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 … !

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.

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.

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.

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!

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.

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.

XForce has created a programmable controller for WS2812B LED strips. The system is based around the Teensy 4.1 and a Nextion display and features remote operation over radio.

The home screen has five shortcuts for favorite effects, which can be combined, looped, and stored on mSD. Strips of up to 4,000 LEDs can be controlled with the current firmware. Learn more in the original thread.

Sometimes the simplest solutions are the best. KD5RXT (Mark)’s “fairly simple” Teensy RV Leveling Helper (TRLH) may not be uncomplicated as a spirit level, it’s a clever solution to a common problem for RV owners.

The helper is placed on RV’s counter to measure whether the surface is level enough. Adjustment info is sent wirelessly to another unit outside, used to adjust the leveling ramps.

Based around a Bosch BMA400 accelerometer, ILI9341 touchscreen display, and a Teensy 4.0, this simple system takes the guesswork out of leveling your RV.

Using vector information from the accelerometer, the pitch and roll angles are then calculated, in turn providing the number of inches that each wheel on the RV (or wheel and hitch on a trailer) needs to be raised or lowered. A built-in LiPo battery with Adafruit PowerBoost 1000 USB charger ensures portability. A new update even allows two units to cooperate inside and outside of the vehicle using nRF24L01 wireless modules. Source, schematics, CAD files and more can be found on the project’s GitHub repo.