YouTuber Zack Freedman wanted to improve his video-editing workflow without spending $100s on new hardware, so he grabbed a Teensy and committed to a one-weekend time limit over which to build his own control surface.

Essentially three normal and one giant knob plus a weird mechanical keyboard, the project is mostly 3d-printed beyond these components, supporting passives, and basic hardware. Source code, design files, and BOM can be found on GitHub, while the accompanying video not only shows you how to put it all together, but also provides a slew of great tips for successful rapid prototyping.

Quint BUILDs is known for impressive, entertaining YouTube videos. Having previously relied on Arduino boards for microcontroller projects, his Knife Throwing Machine presented a new challenge due to the real-time calculations required to launch a knife at exactly the right trajectory for it to nail its target tip-first.

This is where the Teensy 4.1 came to the rescue, in order to provide the 18,000 steps per second required by the motors in use. See the resulting insanity in action in the video below, and then go behind the scenes in the video below that.

Sebastian Tomczak, aka little-scale, has built a homemade drum machine around the Teensy 3.6, entirely on a solderless breadboard!

Sixteen button/LED pairs for step sequencing, two 74HC595 shift registers, five further buttons/LEDs for drum/pattern selection and pattern length, and a potentiometer for tempo control are all intricately wired to a pair of large breadboards.

The four channels provide kick, snare, noise-generated hi-hat, and percussive synth samples. Each voice has sixteen steps and four patterns. Each sample channel has 16 samples to select from, and a low-pass resonant filter tailors the overall output. Nanoloop, Pocket Operator, and Sync 24 (DIN sync) help it play nice with other gear. Learn more on the little-scale blog, and check it out in action in the video below!

1973’s Tektronix Digital Processing Oscilloscope (or “DPO” for short) was comprised of a 7704A ‘scope and a P7001 digitizer, processor, and memory unit. The processing unit could in turn be connected to an external computer, such as the PDP–11 16-bit minicomputer from Digital Equipment Corporation.

This would have been a dream setup in the 1970s, but in the modern era, the chances of finding a working PDP-11 hanging around to plug your old ‘scope into are rather rare. Which is why Holger Lübben designed the Teensy 4.1-based USB+ Interface, to replace the slow GPIB interface (which was limited to about 50 data words per second) and allow direct connection to a modern PC over USB.

The USB+ Interface is connected directly to the internal bus of the P7001 unit, allowing interaction with every aspect of the instrument, including other plug-in cards. Level shifters facilitate interaction with the 5V system. The software-controlled X/Y mode of the P7001 allows arbitrary vectors to be drawn on the ‘scope, which Holger used to create an on-screen menu to help navigate custom software, such as demos, calibration tools, and even a joke of the day. Extensive detail about the project including pictures, documentation and further resources can be found on the project’s web page.

There may not be many fans of the original Xbox controller (aka “The Duke”), but Tom Mason, aka wheybags on GitHub, is a big enough fan to take on the task of dragging the infamous behemoth into another generation of gaming with this USB adapter.

Based on the Teensy 4.1, the adapter simply connects an Xbox extension cable to the Teensy’s USB host pins, and then plugs into a PC via USB. By patching the Teensy 3.x ArduinoXInput_Teensy library to work on 4.x, Tom then brought the necessary XInput USB mode to the device, allowing it to appear as a normal Xbox 360 controller to the PC. Tom has a nice blog post detailing the trials and tribulations involved, and the firmware and FreeCAD file can be found in the project’s GitHub repo.

Tom Magnier created this alternate Ethernet adaptor using using Neutrik etherCON adapter.

While the standard Teensy 4.1 board provides Ethernet via Ti’s DP83825I PHY, we didn’t want to increase the footprint and BOM with a big ol’ RJ45 MagJack, which is why we sell a separate Ethernet kit for users who wish to incorporate networking into their projects. But there are certainly other ways to implement it, which is why we were excited when we discovered Tom’s design.

The Neutrik etherCON Ethernet connector is widely used in the pro A/V world, and uses standard Ethernet cables, but provides a more rugged, panel-mountable solution. Design files, BOM, and a nice assembly guide can be found on GitHub, with the PCB conveniently available for order on Oshpark.

DanielO initially posted with a request for help generating a 10MHz clock signal. What emerged 25 posts later was the release of OpenGalvo, the self-described “minimalistic firmware for processing GCode commands (into the) XY2-100 protocol.”

The reason for doing this? Turning a mirror-based digital galvo into a (potentially unsafe, highly experimental) laser engraver.

DanielO is emphatic about the fact that this is alpha, non-production software that may damage your galvo/laser/Teensy/eyeballs or all of the above, so please keep that in mind should you choose to repro this project. But if you have an XY2-100 galvo, a laser, and a solid-state relay to control it, check out the code on GitHub, and please, please, please be careful and wear eye protection!

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.

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 … !