Blog Posts

Electronic loads are important tools in the EE arsenal, useful for confirming that power supplies, batteries, and other power sources behave as expected. But their expensive prices motivated YouTuber EEforEveryone to create an open-source solution that relies on off-the-shelf PC components for cooling.

A custom Teensy 4.0-powered PCB takes the place of a PC motherboard, providing such facilities as coulomb counting and voltage and resistance measurement.

Up to four load modules can then be added, each using standard CPU cooling to a peak of around 275 watts. Source code can be found on GitHub, and a burn-in test can be enjoyed in the video below.

PJRC forums member rwalters wanted to build an analog mixer with digital control. The analog signal paths meant less expense, but without sacrificing digital convenience. The result is the PGA2310 2×1 Mixer Project.

Components are mostly socketed, so despite the name, a PGA2311 volume control could be auditioned instead, or alternate op-amps selected in place of the OPA2134. TT P260 panel pots and KIL OEJ knobs, combined with a laser-cut hardwood exterior provide a professional-looking finish. And of course, a Teensy 3.2 reads the potentiometers, sets volume output values, and does all the mixing maths. Source code, schematics, and more can be found in the project thread.

We love seeing Teensy boards in use all over the place, from model rockets to jet-engine powered cars, but there’s something extra special about seeing them in space!

Imagine our joy when Ariel University’s Rony Ronen reached out to let us know that the Teensy 3.6 was being used as the main controller in their SATLLA-2B nanosatellite!

The 14×5×5cm sat transmits position and sensor data via amateur radio, which can be viewed on tinygs.com. More detail can be found on the iFixit assembly guide, which provides a comprehensive overview of the DIY satellite and its construction.

The Human League, Yazoo, Gary Numan, Giorgio Moroder, Devo, Prince…Roger Linn’s LM-1 drum machine helped create the signature sound of a huge number of artists in the 80s.

After receiving an original LM-1 as a gift, Joe Britt (of Danger Research/T-Mobile Sidekick fame) decided to create his own enhanced version, based on the original TTL and Zilog Z80 design, but with a Teensy 4.1 coprocessor.

The original hardware design is enhanced with RAM-based samples instead of ROM, allowing the selection of different sounds. The original front panel switches are replaced with potentiometers that enable panning or pitch control. After countless hours of reverse engineering, Joe discovered that Roger Linn lived just five minutes away, and the two became fast friends as they geeked out on the neo-retro project together. The Luma-1 is a work in progress, with new features like an LCD screen, MIDI, and a new metal chassis appearing over time. Read more about on Roger Linn’s web site, and check out a demo in the video below!

Kosmo turned to the trusty Teensy 3.2 and Audio Adaptor to craft a replacement for the out-of-production Kenwood VS-2 Voice Synthesizer, commonly used in HAM radio.

The VS-2 is a voice module for the Kenwood TS-850, TS-690, TS-450 and other transceivers, which announces frequency and other settings upon request, making it of particular utility to blind operators. WAV files can be loaded from SD for complete customization.

Thomas Dettbarn, also know and dettus on the PJRC forums, created a highly portable interpreter for the series of text adventures published by UK video game developer Magnetic Scrolls.

With versions running on Ubuntu, Debian, OpenBSD, macOS, Windows, and beyond, Thomas appears to have tested the the claim that it can run on “anything with a C compiler” and got it running on a Teensy 4.0.

The below shows the game being output to a PC terminal as ANSI art over the Teensy’s USB serial. Compiled firmware can be found in the forum thread, and a hex editor can be used to modify the command line parameters specified within the file, based on the interpreter’s instructions.

John Knoll had added a set of iGaging DROs (Digital Read Outs) to his old manual lathe, but was starting to feel their limitations. They rely on coin cells and are too laggy for precision work.

Inspired by a video of a digital caliper being read by an Arduino, John went on to discover the Touch DRO project, which documented how to talk to several types of iGaging scales. This soon led to the creation of John’s own Teensy LC-based DIY DRO.

From spare parts, John soldered together a protoboard with two 7-segment 8-digit LED displays, two 4-character 14-segment displays, a shift register with 8 LEDs connected, a 4×6 button keypad for input, and a piezo buzzer for audio feedback. John then developed custom firmware and a nice enclosure, and is very pleased with the improvements over the prior budget system. Read more, plus find the source in the original forum thread.

The human eye is an amazing piece of hardware, and various tricks and exploits are used every day to create such illusions as movies and Persistence-of-Vision (POV) displays.

Unlike vampire bats and mosquitos, however, the human eye lacks the ability to see infrared light — that area of the spectrum beyond human-visible red but before microwaves. SugarBombs sets about rectifying this oversight (or should that be undersight?) in the construction of our eyeballs with his Teensy-powered InfraredMirror project.

The device is based around a Melexis MLX90640 far infrared thermal sensor array, which provides a 32×24 “image” of thermal data, in a similar fashion to a (very low-resolution) typical camera sensor, but in the infrared spectrum. This data is then displayed on similarly low-res LED matrix, effectively reflecting the radiation data, or “heat”, in a similar manner to a traditional mirror. Firmware, STLs, and more can be found in the project’s GitHub repo.

Mobile gaming is quite popular, but touchscreen input is often less intuitive and precise than traditional controllers. Sinsid created their TUBG: Teensy Unknown Battleground project for a controller could be used to emulate those touch events!

Sinsid discovered that both iOS and Android support external touch devices, so rather than using an emulator or modded version of the game, a solution emerged that leveraged the Teensy 3.6’s USB Host to intercept controller inputs, then translate them into touch events as if the player were using the screen directly. After figuring out some power and cable issues, Sinsid was able to get a standard Xbox 360 Wireless Controller working well as a touch input, as shown in the video below. Numerous issues prevent use for a complicated shooter like PUBG on iOS, but a second version of the project with an LCD display and the ability to load configurations from a microSD card looks like a promising evolution.

Sometimes you need an Arduino for a project, and sometimes you need a Teensy — but why not both? 1bit created this Teensy/Due-ette Carrier Board to house a Teensy 3.2 and an Arduino Due (or Mega 2560), connected via I2C, plus a whole bunch of other stuff!

In addition to the two aforementioned MCUs, the Due-ette contains two A4988 stepper motor drivers, a socket for an ESP8266, two RS-485 drivers, two ADS1115 16-bit, 4-channel ADCs, a WIZnet W5100 Ethernet controller, and two HX711 Load Cell Amplifiers. It can be used for a peristaltic pump as well as all manner of other applications.