Blog Posts

The Harmonicade is an impressive synth made of over 200 arcade buttons, a Teensy 3.6 and a lot of 3D printing.

The person behind KOOP Instruments wanted to learn to make music, but the traditional piano layout didn’t suit him. So, he started making his own range of musical midi devices, which are now all immaculately written up and shared over on the KOOP Instruments site.

The Harmonicade is a multi-channel MIDI keyboard using arcade push-buttons in a Wicki-Hayden style button layout, a musical keyboard layout based on hexagons. It uses over 200 arcade buttons feeding into a single Teensy 3.6 via two sets of DB25 connectors – an ingenious solution to his wiring problem!

As with all the other KOOP Instruments releases, the Harmonicade has been impeccably documented, including step-by-step build instructions with detailed wiring instructions, 3D modelling files, and helpfully commented code.

You can also read a write up of the Harmonicade on the Hackaday blog.

Scaraman, a PJRC forum user, has shared their progress on a quadruped walking robot project that uses a Teensy 4.

Scaraman wants to make a walking robot that is controlled by a neural network. To achieve that aim, they first had to figure out how to make an ordinary walking robot, the results of which can be seen by watching the video above or by reading Scaraman’s detailed post on the PJRC forum.

Scaraman explains that they chose Teensy 4 to base this first version of the robot on as it has the computing power to run real time neural networks in future versions of the quadruped. One of the interesting design features of this project are the legs and feet. Scaraman has chosen to use a five bar parallel (also known as a five bar Scara arm) design with an extension. The feet also have sensors in them to provide information to the Teensy about foot placement.

For more videos of the robot in action, including it traversing across an obstacle course and climbing up a staircase made of books, check out Scaraman’s YouTube channel.

Jeffrey Turley has made a wearable encrypted password manager using a Teensy 3.2, a Pebble watch and KeePass.

Jeffrey Turley’s Wristpass prototype connects to any computer, emulating a keyboard to input your password. The passwords themselves are secured on your phone by KeePass, which keeps them encrypted until you need to access them. Watch this Teensy powered password manager in action in the video above, or read more about this project on Turley’s Hackster page, where you can also see a couple of his other Pebble watch projects.

Stefan Hamminga has made Scrobby, a robot designed for cleaning solar panels autonomously.

Scrobby was built by Stefan Hamminga using a Teensy 3, a Bluetooth LE module, six ultrasonic sensors and two internal motor driven spools. It is powered by its own solar panel. When Scrobby’s sensors detect rain, it moves across the solar panel surface, scrubbing it clean. When rain stops falling, Scrobby goes back to a special resting platform, meaning that the body of the robot doesn’t block any valuable sunlight. You can find build logs and explanations of Hamminga’s mechanical design decisions over on Scrobby’s Hackaday.io project page.

Holger (C0d3man on the forum) posted details of some excellent synth projects that gets a powerful Dexed FM synth plugin running on Teensy.

Holger combined a custom PCB with a Teensy and the PJRC Audio board to make a neat synth module that supports MIDI, both DIN and USB. Holger also ported multi platform, multi format plugin synth Dexed to this module.

Holger has published details of three separate audio projects that use this system, the Teensy MIDI Audio, MicroDexed and Micro MDAE Piano, all of which are Open Source Software and Hardware. You can listen to a recording of some of the sounds from MicroDexed and Micro MDAE Piano on Holger’s website. You can also read more details about these projects on the PJRC forum and the Zynthian forum.

Christoph has published a number of cool projects over at Hackaday.io. His latest hack, for the Hackaday Tell Time, is turning an IKEA LACK table into a ceiling-mounted robotic LED clock.

Christoph used an IKEA LACK table, twelve small hanging lamps, twelve servos, a Teensy microcontroller and an ESP 32 to make this project. Each lamp can be moved up and down by its own individual servo, stopping at one of five positions: 0% (fully down), 25%, 50%, 75% and 100% (fully up). The position of the lamps tell the time, for example at 01:15 lamp one would be at 75%, lamp two 25% and the rest at 0%. You can find build logs and code for this project over on the Hackaday.io website.

The other winners of the Hackaday Tell Time contest are also really worth checking out. The PJRC blog has previously featured the overall winner, this beautiful and technically impressive ferrofluid clock by a talented team of students from University of Oslo.

Shapiro Audio have released the Skillet, a pro-audio MIDI controller built with two Teensy++ 2.0 boards. The Skillet is designed to be used with Avid Pro Tools.

The Skillet was designed to to control plugins in your DAW in a less fiddly, more interesting way. The device’s joysticks can control up to six parameters, and you can map them to any automatable plugin in Pro Tools. It also has dual touch-sensitive 100mm motorized faders and a nice-looking touchscreen menu system.

The Skillet uses two Teensy++ 2.0s: one to provide USB-MIDI output and convert all the control inputs into MIDI-based protocols, and the other to drive the touchscreen. If this sounds like something that would improve your audio production set up, you can get one on the Schapiro Audio website.

Otmar runs Cafe Electric, a small company that builds electric vehicles.

As part of a recent classic car conversion they used a Teensy 3.6 and 0.96 inch color display to control a modified warning light.

Cafe Electric is a small company in Oregon that builds electric vehicles. Recently they shared details of a classic car conversion that they are working on in which they have used a Teensy 3.6, a custom PCB and an Adafruit OLED screen to replace a warning light.

Since a @Tesla based classic car conversion wants to look unmodified, we’re replacing a warning light with a @adafruit screen running on @PaulStoffregen Teensy 3.6 with CAN interfaces on a @oshpark PCB.
Testing the images today. pic.twitter.com/1ygAAtYbMe

— Otmar (@CafeElectric) December 7, 2019

The schematic, bill of materials and KiCad files have been published on the Cafe Electric website and you can download the board files or order yourself a PCB on the OSHPark website. You can also follow Otmar from Cafe Electric on Twitter for more updates on this and other electric vehicle projects.

Christof made a very cute cuckoo clock that tells the time with a ring of NeoPixel LEDs and marks the hour with a moving, singing wooden bird.

Christoph is from a region close to the Black Forest in Southern Germany, a region that is very well known for its beautiful, quirky cuckoo clocks. Traditionally these intricate clocks are mechanical, but Christoph’s version uses electronics and code.

This cuckoo clock uses a NeoPixel ring to display the time. On the hour, a servo opens the shutter, letting the bird peek out. The bird then sings, using a small speaker and the ever reliable LM386 chip to handle sounds stored on a SD card. The whole project is controlled by a Teensy 3.5.

For more information on the project, including more pictures and details of the libraries used, check out the original post by Christoph on the PJRC forum.