ARTI – Audio Recorder

ARTI is an audio recorder and terminal interface created by StanoCPW. It is designed to record both the audio and signaling from a radio terminal.

While implementing audio capture was relatively straightforward, the data had to be intercepted over I2C between the radio terminal’s transmitter and operation console, in order to obtain meta information about the transmission. ARTI records audio and data to a microSD card, and can connect to a PC over USB for data management, or will automatically delete old records after a year or when the card is full.

Electronic String Instrument Version 2.0

We saw the first version of Peter Wiessenthaner’s Electronic String Instrument back in 2020, but Peter and his collaborators are back with a new version 2.0.

Improvements include 189 RGB LEDs to provide feedback to the user, as well as new tuning systems which are represented by distinct LED colors. A Kinect V2 camera provides gesture control. The Teensy 3.6 takes the camera input data from a laptop and controls five motors and the LEDs. New programs allow traditional playing of the instrument or guided playing by following the LEDs, as demonstrated in concert performances and public exhibitions throughout Europe and the US.

Model Railroad Control System

Who doesn’t love the scale realism and joy of driving model trains? But like the real thing, complicated networks can present all manner of issues, resulting in miniature delays, damaged tiny cargo, and … well, not having fun! That’s why Chuck Davis created the Simple Signal System (S3).

More than just a model railroad control system, the project can actually be used for lighting or almost any kind of control project.

The S3 features eight inputs and 16 powered outputs, with two network connections that enable the addition of up to 50 expansion boards. RS485 multipoint and simple modular cables connect the expansions using a simple communications protocol. Custom PC software allows point-and-click configuration with no programming or special knowledge required, resulting in the generation of custom firmware to be deployed to the Teensy 4.0 that provides the main board’s brains. A larger Teensy 4.1-based version, with 16 inputs and 32 outputs, is also available. Find out more at railroadcontrolsystems.com.

MRCC – MIDI Router Control Center

Everyone loves a crowdfunding campaign that delivers what it promised, and surely the only thing better is a campaign that delivers using Teensy!  Conductive Labs MIDI Router Control Center (MRCC) did for more than 240 backers. But what does MRCC do? Let’s dive in!

Zenbob describes it as “super deluxe high performance MIDI router,” featuring both traditional 5-pin DIN MIDI and modern 3.5mm input and output jacks, as well as 4 USB host ports for USB MIDI devices (or even a keyboard!). A USB client interface provides 12 virtual USB MIDI ports to your PC or tablet device. And if that’s not, an RJ45 port allows the addition of even more MIDI ports, anywhere you can reach an Ethernet cable. An OLED display and encoder, plus a button and RGB LED for each input and output mean you can do all of your MIDI routing without having to touch a PC! Find out more and order yours at the Conductive Labs web site!

Sound Reactive LED Strip Animation

Every project is sexy in its own way, but we have to admit that LED projects possess a certain overt sexiness.  Luca Paolini is putting everything on full display with what he describes as “sexy, audio-responsive effects on LED strips” aka the Striptease library.

Luca has also developed custom hardware around our Audio Adapter Board, with PCBs available for Teensy 4.0 and 4.1 to house the 74HCT245 level shifter required for 5V WS2812Bs, as well as connectors and an IR receiver. His implementation features professional Neutrik speakON connectors for enhanced durability and current handling. Functionality is abstracted across several classes in a well-documented API, which can be found along with schematics and source on GitHub. Enjoy the combination of hardware and software in all of its sexy glory in the video below!

Advanced Line-Following Robot

Line-Following Robots are a fun way to get started with robotics, as well as to compete with others to see how your skills stack up. Midhun has created a unique, well-documented LFR.

An array of IR LED/phototransistor pairs in the form of Pololu’s QTRX line sensors give the bot eyes, while perfboard is used not only to connect its various breakout boards, but also to form its chassis. Dual 6V 1580 RPM high-power 15:1 gear motors power the unit, with encoders for position and distance estimation and the 10DOF motion sensors from our own Prop Shield providing heading and position. A  SparkFun TeensyView displays telemetry, calibration and other functions. An overview of the LFR can be seen in the video below, with complete, detailed build instructions on Instructables.

USB Data Acquisition

We see a lot of Data Acquisition (DAQ) projects on the Teensy forum, but this offering from experienced engineer DrM really caught our eye.

This USB DAQ model has been specifically designed around the characteristics of Teensy 3.2’s ADCs and DAC, and when paired with a precision current amplifier can provide measurement into the pA and pF ranges.

Custom Python control software provides a cross-platform GUI and CLI, and can be automated by piping data in a column-formatted ASCII file. Typically this kind of functionality would require hardware in the range of $100s if not $1000s, and that’s before the frequently even more expensive software and seat licenses. While the board is currently just a prototype, DrM is interested in producing more if there is interest — so be sure to let them know in the forums if you’d like to get your hands on one!

16N – Sixteen Fader Synth Controller

16n is a bank of faders” proclaims the  release thread on the Lines forum, and, what more could we say — it really is “just” a bank of sixteen faders.

But say more we must, because there’s a minimum expected word count for these blog posts, so here goes: more than just a pile of 60mm faders whacked onto a PCB, the 16n is a Teensy-based control interface that outputs MIDI over USB and 3.5mm stereo TRS, 0-5V CV out of sixteen jacks, and I2C over another TRS jack.

The result is an extremely flexible controller that can be used for almost anything, from Eurorack modules to DAWs to devices from the Korg volca line. The 16n is based on original work by Brian Crabtree and Sean Hellfritsch, with additional contributions by Tom Armitage, and firmware by Brian Crabtree, Tom Armitage, and Brendon Cassidy. An overview can be found on the project’s web page, with further details, including a detailed build guide, on the GitHub wiki.

Remote Controlled Riding Mower

We love seeing Teensy boards shoved into all manner of things in order to give them new capabilities and lives beyond what their original creators envisioned; souped-up toys and remote-control-ified gadgets.

This particularly large toy really caught our attention: Jesse Brockmann upgraded his 500-lb vintage John Deere 110 Mower with Teensy 3.2-powered remote-controlled steering, braking, and throttle.

The steering motor is driven by a Pololu Simple Motor Controller G2 18v15, while linear actuators handle the brakes and gear shifting. The mowing blade has already been removed, but additional safety measures include a safety tether, an energized relay that will close and shut off the ignition if power is lost, which is also connected to Teensy’s own watchdog. Jesse’s custom JRover breakout board facilitates servo and I2C hookup. A standard R/C transmitter and receiver is used for control. Find out more on SparkFun’s blog, or in the video below!

AC Powerline Frequency Monitor

We see a lot of data logging projects but jp3141 created one that caught our eye, with a device that captures the slight variations that occur in AC powerline frequency.

In the US, AC power is generally accepted as being 60Hz, but in actuality, it drifts, as can be observed via the University of Tennessee’s FNET service. jp3141’s Teensy 3.2-based device uses two of the board’s FlexTimer Module interrupts (FTMs) to measure the frequency of the power line, plus calibrate the onboard 48MHz clock using an external GPS’s 1pps calibration pulse.

Data is transmitted both via the Teensy’s own USB serial, and to a Raspberry Pi Zero W where it is logged and graphed via a Python script. A 9V AC adapter powers both boards at 5V DC, as well as providing the 60Hz AC sample to be filtered and measured.

An example of drift over time can be seen in the plot below. More information, as well as the Teensy code and Python scripts can be found on GitHub.