Blog Posts

The heyday of the Hi-Fi is lamentably behind us, with elaborate consoles that once took pride of place in the living room replaced by slim soundbars under TVs, or often obviated completely as tinny handheld devices become peoples’ only multimedia interface.

But if you want to add a VU meter or spectrum analyser (or both!) to your system, Mark “The Electronic Engineer” Donners has just the (Teensy-based, of course!) thing!

Mark’s solution consists of a custom PCB that houses a Teensy 4.1 (with PSRAM), our Audio Adaptor board, and dual ILI9341 displays.

Source audio can be via stereo line in, or an optional mono electret microphone. Gerbers and firmware are available on GitHub, with complete instructions on Instructables.

Ted Fried aka MicroCore Labs is back with another Teensy-powered retro rocket! In January we featured the “world’s fastest” Commodore 64, which used Ted’s drop-in 6510 CPU replacement, the MCL64.

With the C64 already off and breaking records, it was time to turn his tuning skills on the TRS-80 Model III.

Like the MCL64, the MCLZ8 is a drop-in replacement for the machine’s original CPU, in this case the 8-bit Zilog Z80. With cycle-accurate emulation already in place, Ted is of course already scheming ways to improve performance, like moving the Model III’s RAM/ROM inside the Teensy 4.1 as well.

Be sure to check the MicroCore Labs blog for updates, and as always, the Projects GitHub repo for schematics and firmware.

The lines between Single Board Computers and microcontrollers are starting to blur, especially when it comes to powerful boards like the Teensy 4.1.

While displaying video may be trivial on an SBC like the Raspberry Pi — which has all the facilities of a full Linux operating system — a similar task on a MCU typically requires rolling one’s own firmware and potentially even creating custom codecs. PJRC forum member 1337Misom had a go at rolling their own with the MjpegTFT_t4 Mjpeg-like Video Player for the Teensy 4.1 development Boards.

Encoding a file for MjpegTFT_t4 requires ffmpeg and Python, as well as the Teensy Audio Library and forked versions of the Teensy Audio Codecs and ILI9341_t3n, plus Larry Bank’s JPEGDEC library. Add a simple header and AAC audio, and you have a beautifully performant series of JPEGs on your TFT, just like the video below!

Inspired by the Shruthi Synthesizer from Mutable Instruments, German maker and synth enthusiast Rolf Degen set out to create a small, portable, Teensy 4.1-based polyphonic synthesizer.

The entire journey is documented in a 10-page thread on our forum, and represents not only Rolf’s quest to create his dream instrument, but also a great coming together of the Teensy community as folks jumped in to debug, optimize, and provide encouragement.

Rolf’s Jeannie kit produces an incredibly sophisticated 8-voice polyphonic synthesizer, with 15 banks of 63 waveforms, a waveshaper for refining the sound further, and a multimode filter with low/high/band-pass functions. A built-in 16-step sequencer transforms the synth into a tiny groovebox, capable of producing entire tracks.

While the Jeannie is a DIY kit, the surface mount work is done for you, so users get the satisfaction of creating their own instrument without the chore of SMD soldering. Jeannie is available in small batches from Tubeohhm in Germany. Firmware and schematics can can be found on GitHub, while example tracks created with Jeannie are available  on Soundcloud, and Facebook hosts a user support group.

Many developers turn to Teensy when speed is critical, but we didn’t realize our reputation extended to the Bonneville Salt Flats!

Teensy forum user noisymime, aka Josh Stewart, developer of the Speeduino open-source engine management system, has been trying his hand at turbines, rather than piston-powered engine controls. He recently developed a  Teensy 3.5-powered full authority digital engine control (FADEC) for the 4000+ horsepower jet-engine-driven Turbinator II as part of a land speed record attempt.

Technical issues prevented a full 5-mile pass, but a shorter 3-mile run resulted in the fastest 1st, 2nd and 3rd mile speeds in the history of Bonneville Land Speed Racing, with peak GPS speeds of 447.9mph and a 3-mile average of 420mph. Watch the world’s fastest* Teensy, complete with data overlay, in the video below!

*have you built a faster Teensy-powered vehicle? let us know via the forums!

Some music producers like the hands on, computer-free, tactile experience of twiddling knobs on a modular rack. Others prefer a USB control surface connected to a PC.

But Sebastian Tomczak envisioned a scenario with the best of both worlds: a direct interface between USB MIDI controllers and CV-based Eurorack synths — without the bulk and expense of a computer in the middle!

The Teensy 3.6 has a USB host port (requires soldering of pins and USB Host Cable), and the ability to read and write voltages, as required to interface with a Eurorack system. This makes it the perfect intermediary between the two, and completely obviates the need for a computer.

With the addition of some 1k resistors and standard 3.5mm Eurorack sockets, plus code to read and store button presses in an array, a simple yet effective pattern sequencer can be realized. Additional detail can be found on Sebastian’s blog, while the example code resides on GitHub, and a sequencing demo can be found in the video below.

NOTE: PJRC recommends caution when interfacing Eurorack signals with Teensy.  The Teensy 3.6 pins can be damaged by voltage higher than 3.3 volts, or below ground.  Many Eurorack modules use -5V to +5V or -10V to +10V signals.  Opamps, buffers, or other circuitry are typically needed to safely connect these higher voltage signals to Teensy’s pins.

 

One of the most exciting aspects of the maker movement is its ability to empower individual enthusiasts with technology that was once the realm of large corporations and universities. A particularly impressive example of this phenomenon is McGill University Physics PhD student Dan Berard’s Teensy 3.1-based low-cost scanning tunneling microscope (STM) project.

Using a cheap piezo buzzer, Dan has accomplished atomic resolution with select materials, using a manually sharpened tip.

A detailed explanation of the techniques and components used in the project, as well as some incredible images generated by the system can be found on Dan’s blog.

Creative coder Eric Furst (@ef1j@post.lurk.org on Mastodon) is a master of retro-modern mashups.

For his latest project, he ditched the retrocomputing angle and went full futurism, using a Teensy 3.1 as the basis of his Dystopian Drone.

The Teensy outputs a continuously-evolving synthesized saw wave sound, which is then broadcast worldwide at http://echo.lurk.org:999/ef1j.mp3 as well as locally on 89.3 FM via a simple external transmitter. The result is deliciously chilling, and provided the perfect sinister soundbath for the authoring of this blog post.

Give it a listen, follow the project’s evolution on Mastodon, and be sure to take a gander at Eric’s wiki for more details on this and other creative coding and computational art projects.

UK-based engineer and YouTuber Tom Stanton had a dream: to dress up and launch sausages at ungodly speeds. Well, maybe that wasn’t the original dream, but it’s somehow where things ended up?!

As reported on our own forums, Stanton designed and built an incredibly impressive Teensy 3.5-based Electromagnetic Rail Launcher, consisting of a linear motor (as opposed to the more typical circular examples which rotate a shaft) and a track down which magnetic material can be propelled.

Said material might be a paper airplane (via magnetic sled), or, as alluded to earlier…a sausage with googly eyes and a smile.

Watch both below, along with a second video showing a more optimized version launching a sturdier 3d-printed aircraft.

The year is 1994. Quentin Tarantino’s magnum opus, Pulp Fiction, is demolishing the silver screen, while Ace of Base dominates the pop charts with “The Sign”, “All That She Wants” and a cover of Aswad’s “Don’t Turn Around.”

And being the gadget-obsessed dork that you are, you just picked up the latest Microsoft x Timex colab: the Data Link wristwatch compute. While all the other nerds are eating up Martha on their clunky Apple Newtons and pretending that they can touch-type on their chunky Psions, you carry the world on your wrist.

Except it’s not 1994. It’s almost a full three decades later, and music is confusing and strange and nobody goes to the movie theatre anymore because there is a tripledemic and they can just binge on boring tiny slabs at home without the malodorous stench of stale popcorn. But that’s not all: the CRT displays that are required to sync with your Windows 3.1 desktop are becoming ever-rarer. So what do you do? Well, if you are Maxwell Pray AKA @synthead on GitHub, you grab a Teensy LC. The Timex sync relies on pulses of light to transmit data, so the LC’s built-in LED already gives you everything you need to emulate the original hardware. With this in hand, you can grab Maxwell’s emulation software from GitHub, and you’ll be transferring your appointments, anniversaries, phone numbers and reminders at speeds of up to 1K/minute, just like in the good old days…!