Blog Posts

Octo-Bouncer Automatic Ping Pong Bot

For years, maker and blogger Tobias Khun carefully considered the question: what would it take to build a robotic ping pong player capable of keeping a ball in motion for hours on end? The result, the Octo-Bouncer, is the perfect mechanical juggler.

The ping pong paddle takes the form of a horizontally-aligned clear acrylic plate which is carefully controlled by four servo motors driven by a Teensy 4.0. In order to determine when it’s time to move the plate (and how including angle and force), the Octo-Bouncer turns to computer vision analysis of a camera feed for a See3CAM_CU135 camera module located beneath the clear plate.

The analysis is performed using openCV running in Unity at a whopping 120 frames per second. The program uses a custom ball detection algorithm and includes data visualization of the ball’s location. Having iterated on the project for over five years, Khun is still making improvements to the programming which he’s open sourced including most recently adding plate tilt visualization, hit position prediction, and analytical tilt control. The project is also a marvel of manufacturing with over 150 CNC-ed parts that and Khun has generously provided the Fusion360 files for on Github.

 

Car in a Case

UK-based IT specialist and car hacking hobbyist Ian Tabor recently shared his Car in a Case project to his Twitter account.

Tabor, a network architect who in his spare time explores the security vulnerabilities of automotive computing systems, created the Car in a Case using four Teensy 4.0’s as the main ECUs or Engine Control Units.

The Car in a Case works as an effective Portable Automotive Security Testbed with Adaptability also known as a PASTA. PASTAs, which you can either purchase or (as demonstrated by Tabor) DIY for a slight discount in cost, are used by professionals and hobbyists alike to test the vulnerabilities of a car’s computer system to cyber attacks. PASTAs can also provide valuable opportunities for researchers and developers to learn more about the vehicle’s ECUs and the ways the various components of the car’s electrical system communicate with one another.

Tabor says he created the Car in a Case to make car hacking more accessible in the UK and Europe. If you’re intrigued and would like to know more about car hacking, Tabor has an entire blog dedicated to the subject that is full of projects, videos, and more for you to explore.

Game-o-Tron Mini

The Game-o-Tron Mini is a pint-sized but powerful handheld game console with a nostalgic look and feel.

About the size of a credit card, the mini uses a Teensy 3.2 to drive a 128×96 pixel OLED display and speaker. Inputs include 8 push buttons and an on / off switch with a rainbow color scheme reminiscent of the Nintendo 64 controller. The entire device is powered by three AAA batteries which fit snuggly into the 3D printed case alongside the other electronics. The mini is the third in a series of game controllers designed by UK-based maker David Boucher. The Game-o-Tron 3000 uses a Teensy 3.1 and a 320×240 pixels screen. While software development for the mini is still in progress, the complete software and hardware development process for the 3000 is available on Boucher’s website.

Some of Boucher’s other interesting projects include a pocket-sized EDSAC (Electronic Delay Storage Automatic Calculator) and a Teensy command line compile program which allows you to run Teensy code from the command line.

MultiDrum and VCO Firmware for Radio Music Module

Raphaël Hoffman, a Belgium-based engineer who runs the one-person company Hora Music, has produced two alternative firmwares for Music Thing Modular’s Radio Music—a popular module used in the DIY modular synth community.

The MTM’s Radio Music is a widely-appreciated virtual radio Eurorack module that includes 16 banks and stations. The Complex VCO firmware (which also works with MTM’s Chord Organ module) features a complex oscillator built using a vult transcompiler which allows for morphing between sin and tri waveforms. These waveforms can also be folded up to 16 times to generate rich harmonics.  The second alternative firmware—MultiDrum—is its drum machine counterpart. It includes three “analog” sounds (kick, snare, and high hat) created from models instead of sound samples as well as 6 LinnDrum samples including: kick, snare, clap, closed hi-hat, open hi-hat, and cymbal. Users can set the sample decay and play 2 samples simultaneously to create more complex patterns. Both of Hoffman’s firmwares are based on the Teensy 3.1 and are available for sale on the Hora Music website.

 

Mano-Matic: 3D Printed Bionic Hand

The Mano-Matic is a Teensy-powered 3D printed bionic hand, created by HandSmith.

HandSmith, based in Virginia (USA), is a 501c 3 organization dedicated to producing affordable 3D printed bionic prosthetic devices. HandSmith is the brain child and passion project of software engineer Lyman Connor who works for General Electric as his primary occupation but in his off hours operates this remarkable not-for-profit dedicated to developing bionic hands for those who could not otherwise afford them.

Bionic hands can cost upwards of $45,000 USD—a figure which is especially staggering when considering additional costs of bionic limbs such as ongoing maintenance, replacement and medical check ups. Connor relies on a network of four SLA Formlabs 3D printers to develop the products using Formlabs’s Tough Resin which is robust and durable enough to withstand ongoing use. Using this approach, Connor can create limbs at a fraction of the cost compared—up to 1/10th of the cost in fact as well as provide them for individuals whose insurance will not cover the expenses of a bionic appendage.

 

Guitar Pedal Expresses Pain

We use our electronics everyday, and may consider how using our various devices makes us feel, but do we ever stop to consider how the electronics are feeling? Andrew J Harvie raises this question in a recent project that takes the form of an unusual guitar pedal—one capable of expressing pain.

When the pedal is deactivated, sound will pass through it just as with any normal guitar pedal. However, when the pedal is activated and silence is detected, it will commence begging for mercy from the user. Should the user choose to ignore the pedal’s pleas and step on it anyway, relentless screaming will ensue.

Harvie claims that the pedal will “change how music is played forever into the future,” a claim that may be supported by just how off-putting the pedal’s lingering cries of “Help! No don’t!” are.

To drive the sound interactivity, Harvie used a Teensy 3.2, although it’s unclear how the Teensy felt about it. For those who would like to make their own emotional instruments, you can find the full source code to the project on github with instructions forthcoming.

ImSoDopeaHedron – Infinity Mirror LED Sculpture

The ImSoDopeaHedron is a beautiful and mesmerizing LED sculpture by maker and designer Tom Schubert.

The project was inspired by Neil Merchant’s Dodecahedron which also uses an infinity mirror approach to create hypnotic LED effects that highlight the sculpture’s geometric structure.

Schubert has shared a few videos so far of palettes and sound-reactive lighting patterns he’s created using FastLED for the sculpture—including tests from Bowie’s “Rocket Man” to vaporwave—which you can watch on his Youtube channel. Schubert has also shared photos of the making of the sculpture for makers who are considering building their own or a similar project.

To build the ImSoDopeaHedron, Schubert wired up high-density Neopixel strips to line each of the sculpture’s joints resulting in five strips of six sections running in parallel. This creates a star burst pattern of light where the five segments meet, the effect of which is absolutely entrancing to watch when replicated within the sculpture’s mirrored interior. The 1,440 LEDs are driven by a Teensy 3.2 while the infinity effect is created by lining the sculpture in .6mm two-way acrylic.

AURA – Sound Reactive Art Installation

German designer and artist Alex Rex has created many installations combining sound and electronics. One of his most recent projects, Aura, envisions what it would take to make a field of wooden rods sway in response to the notes from a piano, clarinet, or other instrument.

To realize the project, he uses a Teensy 3.5 and Teensy Audio Board to control a series of motors which direct the movements of wooden rods according to sound input from a microphone. The effect is a beautiful and whimsical installation where the surrounding rods appear to come to life in response to live music.

Not only is the project itself impressive, but even more impressive is Rex’s decision to use the project’s documentation as a platform for educating others about how to create musical electronic installations. He’s devoted an entire section of his website to tutorials which can help even beginners learn how to build reactive audio environments like Aura with both budget and materials in mind.

Rex’s tutorials are extremely thorough, including custom diagrams, parts lists, and step-by-step instructions with annotated source code. He takes things a step further by showing interesting ways in which sound can manipulate movement through examples of linear, rotational, and algorithmic models including videos of these models applied to outputs such as servos and LEDs.

You can view more of Rex’s projects including a machine which ignites and extinguishes matches and an exploration into alternative materials for producing vinyl records on his portfolio website.