Sei had two things: a bare wall in their apartment, and a tendency to (their words!) “waste money on useless electronics” — and thus Plotbot was born.

Powered by a Teensy 3.1 and a pair of Nema 17 stepper motors with SilentStepStick TMC2209 drivers, the system uses an extruded aluminum frame and arms in conjunction with a system of pulleys to drag a pen over a large sheet of paper, creating the desired drawing.

More information can be found on the project’s Hackaday page and GitHub repo, with a quick demonstration in the video below.

POCSAG Pager Transmitter

EverestX on SOLDIERX yearned for the simpler times of the beeper, and decided to bring them back at a personal scale with a custom Teensy-powered POCSAG pager transmitter.

In the days before everyone carried boring black slabs of always-on hyperconnectivity around in their pockets all day, being reachable away from your desk or home was actually fairly unusual — the domain of doctors, network admins, and … certain other high-income individuals. But with a growing desire among many to disconnect and simplify, the former status symbol of wearing a pager might today appeal as a minimalist messaging solution.

In addition to the Teensy LC and custom PCB, the system incorporates an RFM23BP ISM radio transceiver and HC-05 Bluetooth module. Adopting the Featherwing format resulted in some tight tolerances, but is great for prototyping, and results in a compact build that can be powered by a LiPo battery and charged via USB. EverestX didn’t even have to write any code thanks to the pocsag Arduino library by on1arf on GitHub. Read more about the project’s background, philosophy, and build notes on SOLDIERX.

Commander Keen Game Emulator

Ryzee119 demonstrates the Teensy 4.1’s superior performance with a port of the Commander Keen “Commander Keen in Goodbye Galaxy!” series!

Perhaps best known for first-person shooters like Wolfenstein, Doom, and Quake, id Software’s Commander Keen, the side-scrolling adventure based on their Super Mario Brothers 3 clone for PC, was also an incredible shareware success.

Ryzee119 used the Omnispeak C clone for Windows and Linux as the basis for his Teensy emulator. Requiring just a 64Mbit of PSRAM and an ILI9341 TFT LCD Display, OmnispeakT4 supports save games via SD, Xbox 360 controller input via USB, and with an optional YM3812 OPL2 FM-synthesizer board, genuine OPL AdLin audio synthesis too!

Wiring and compilation details for OmnispeakT4 are available on GitHub, and a video of it in action (complete with sound) can be found on Imgur.

DIY Polyphonic Synth

Florian Loretan bought an old Bontempi keyboard, but it stopped working. Instead of consigning it to the scrap heap, he ended up on a journey to create a custom polyphonic Teensy-based synth, with the only remaining part of the original keyboard being the keys and matrix.

In addition to the Teensy 3.1, an Audio Adaptor Board is used, though not in the typical stacked orientation. Multiplexers handle the keyboard matrix and the custom potentiometer-based interface. More detail on the electronics can be found in a separate video, as can specifics on building the case, and a demo of everything together can be seen below. The source code, which is still a work in progress, can be found on GitHub.

CNC Milling Machine Control

Armin Rehberger has implemented a Teensy-Raspberry Pi hybrid overhaul of a CNC mill. The Raspberry Pi provides the user interface, then transfers the selected G-code to a Teensy 4.0 (up to 7,500 steps) for real-time control of the system.

Manual mode allows nudging in each direction on each axis. Spindle, coolant, clamp, light, and the 0-10V that determines speed can also be controlled.

The system also features an automatic tool length sensor and emergency stop. Source code and documentation can be found on GitHub, and a demonstration of the system can be seen in the video below.

MIDI Controlled Barrel Organ

Sometimes a project comes across our desks that just makes us laugh, in the best possible way.

This was the case with the Hamlet Organ, the creation of luni64’s daughter. If you just want to hear the most adorable sound ever to come from a Teensy, skip to 2:00 in the video below, but try to stick with us as we share a little more about this Teensy 3.6-powered MIDI-controlled barrel organ.

This amazing 3d-printed instrument uses MajicDesigns’ MIDI parser to read MIDI files from the Teensy’s SD card, combined with Adafruit’s PCA9685-based 16-channel PWM driver to control the 16 servos that control the organ’s 16 valves.

OK, now you can listen to the charming little tooting sounds in the video below:

Steel Battalion Controller

Not content to relegate this 44-input beast to prior decades, SantiagoSaldana decided to give Steel Battalion mecha controller an Xbox 360-compatible USB XInput interface, with a little help from the USB capabilities of the Teensy 3.6.

By acting as a USB proxy of sorts, the interface even improves on the unidirectional capabilities of the original, allowing visual representation of haptic feedback, rather than just one-way input. Since it presents as a normal HID device, it can even be used with the Oculus Quest (and 2) for a truly immersive mecha piloting experience.

Complete instructions can be found on the project’s Hackaday page, with its custom library available on GitHub, and a gameplay demo viewable in the video below.

Mouse Tailor

Claghorn decided to create a Teensy-based hardware intermediary to transform any input device as desired before the OS even sees it.

Frustration with newer Linux distros, especially the transition from X11 to Wayland, was the main motivation.  While it’s open source, allowing you to theoretically tweak it to work however you like, the reality of technology marches on with large rapidly changing code is sometimes leaving that one special feature that you loved in its wake.  Button mapping and drag lock – completely gone.  By intercepting communication, the many features of a special complex mouse can be reassigned in any way.

The Mouse Tailor, as the resulting box is called, simply takes the mouse or other input device’s output via the USB host port, transforms it as required, and then passes the result to the connected computer as a Human Interface Devices (HID) device, appearing as if it were just a normal mouse. Source code and a detailed recounting of the journey to get there can be found on the project’s web page.

MRSC the Ultimate CWmodem

Morse code lives on in the form of CW (continuous wave) transmission, which brings us to this Teensy-based CWmodem from Johan Holstein (aka PD0LEW).

The MRSC Signature features a custom PCB and aluminum enclosure, with various available RA8875 and HX8357D-based touchscreens. A USB keyboard can be connected as an input device, in addition to the typical paddle preferred by CW enthusiasts. A wealth of options and settings are available, which you can find in extensive detail on the project’s web page, along with more pictures and videos of the device in use.


Boy Harsher X Moffenzeef: THE RUNNER

Darkwave artists Boy Harsher have developed a cult-like following over the past decade.  To create a drone synth to tie in with their directorial debut film, The Runner, they reached out to Moffenzeef Modular’s Ross Fish, creator of the Teensy-powered STARGAZER.

While we don’t have a ton of insight into what’s inside the box, we do know it’s powered by a Teensy 3.2, and can assume that it uses the Teensy Audio Library like Ross’ other creations. Give it a listen in this six-minute demonstration video, or scour Reverb or Mod Wiggler for a used one, since the limited edition run of 250 units is already sold out!