DeftAudio, aka Andrei Kudryavtsev has created an 8×14 1U MIDI and Audio Interface based on the Teensy 4.1.

With 8×8 5-pin MIDI DIN in/out, plus six MIDI TRS outs (which can also be configured as 5V Trigger out or Sync out for controlling Eurorack modular gear, drum machines, or analog synthesizers), as well as USB MIDI and a 2×2 audio interface, which seems almost absurd for a kit that starts at $25 for the main PCB. An OLED display and two rotary encoders provide the interface.

Best of all the project is completely open-source, with schematics, firmware, and even the enclosure available on GitHub. The “Complete Electronics” kit (bring your own Teensy and front panel) is just $40, while the fully assembled model will set you back $225 — still a steal for this level of functionality. Check out the video below, then head over to Tindie to pick up a kit!

Alex Lorman had two things: a 2006 4Runner and a desire for year-round posterior comfort. So he picked up some OEM switches. And some commodity seat heaters. And a whole bunch of knowledge along the way!

The project culminated in a custom PCB, primarily as a home for the MOSFETs required to drive 10A per channel to the heaters. And to manage state and the MOSFETs, a Teensy 3.2 was employed.

One interesting aspect of the project was the employment of low-rate PWM to allow the MOSFETs to avalanche while capitalizing on the high resistance of the heated heaters to enable self-regulation. A GitHub repository serves as a clearing house for information and resources related to the product, with two further repos for the PCB and code.

Jigglypuff works in a noisy office, and wanted to avoid the complaints that their built-in laptop mic was garnering during Teams meetings.

Instead of juggling muting in the software itself, they converted a vintage Turner CB desk mic into a digital USB microphone using Teensy 4.0.

After an initial prototype proved unsatisfactory, Jigglypuff switched to the Teensy Audio Shield and a PUI AOM-5024 series electret condenser mic. Unfortunately, the Teensy Audio Shield would not fit inside the Turner, leading to the creation of a custom shield without unwanted features like the mSD slot and line in/out. The final device features push-to-talk with an LED if the mic is active, a pot for mic gain adjustment, a 125Hz high-pass filter, and the all-important ability to present itself as a microphone, not a full-duplex sound card (since it has no output capabilities). Pretty impressive for someone who claims “EE and software is not my primary background.” Learn more and follow the journey in the PJRC forum thread.

Long-time PJRC forum contributor ghostintranslation is back with a new version of the Drone Eurorack module, dubbed Drone 2.0 for its basis on the updated Motherboard 2.0 platform.

The module features four voices with sine and resonant noise oscillators, FM control voltage (CV), individual volts per octave, and a TRS MIDI.

The Motherboard platform underpinning all this was designed to facilitate the creation of new modules, without having to start from scratch every time, and itself features 16 inputs and outputs, MIDI in/out, 10-pin Eurorack power, and Teensy 4.0-based firmware and examples.

Drone 2.0 is available as a PCB/panel kit with SMD components prepopulated. The required BOM, as well as firmware and schematics, can be found in the project’s GitHub repo. Listen to example sounds below!