Radio Telescope for Pulsar Detection

Amateur astronomer JJ has made a radio telescope for detecting pulsars.

JJ’s DIY radio telescope detects electromagnetic radiation from neutron stars. Pulsars are rotating neutron stars that are highly magnetised. They emit a beam of electromagnetic radiation that, due to the rotation of the star, appears to be pulsing to an observer. JJ built a radio telescope designed to observe these pulses of radiation. They recently detected their first pulsar.

In JJ’s design, the Teensy 3.2 is used as an analog to digital converter, digitalizing the signal at the output of the radio telescope’s detector. JJ reports that the Teensy 3.2 performed really well in this role, but that learned that they needed to deactivate the LED blinking as it showed up in the data, with both the LED blink and the pulsar period being close to one second.

There are more pictures from JJ’s project below. To find out more about this impressive build, visit JJ’s website or take a look at their report on technique, testing and first observations. 


Atari 520ST Emulator on Teensy 4.0

Jean Marc is using the Teensy 4.0 and a wide angle LCD screen to run an Atari 520ST emulator and play classic games.

This pocket-sized retro gaming emulator by Jean Marc packs a punch, supporting five classic gaming consoles: the Atari2600, the Philips Videopac/Odyssey, the Colecovision, the NES and the Atari800. Jean Marc uses a Teensy 4.0, a TFT LCD screen, an analog joypad and a few buttons to create a system that can play classic games including RoboCop, Rick Dangerous and Red Heat.

Part one of the Teensy 4.0 Atari build video is above. You can see the rest of the build plus examples of it in action in the second video below. You can find Jean-Marc’s code for this fantastic retro computing project on his GitHub, along with pictures of his wiring and build processes.

Koka’s Orchestra Interface

Koka Nikoladze is a composer and DIY instrument maker who has made a project called Koka’s Orchestra Interface (KOI), an experimental device that uses LEDs to communicate musical compositions to instrumentalists.

Koka Nikoladze uses Koka’s Orchestra Interface (KOI) to compose live in front of an orchestra. He turns knobs and pushes switches on the KOI much like an analog synth, but instead of manipulating a sine wave he is sending instructions to human instrumentalists. The KOI uses a Teensy and LED lights to communicate the score in real time to up to 150 musicians via their note stands.

This experimental composition project was made as part of the Bebeethoven fellowship program, an initiative supporting innovation and radical thought in music creation as a way of celebrating the 250th birthday of Ludwig van Beethoven.

LED Audio Meter

Nicolas Toussaint has made a two channel audio meter using a Teensy 3.1, a PJRC audio adapter and two strips of NeoPixel strips from Adafruit.

An audio meter is an essential device in music production, displaying a visual representation of audio signal level. Toussaint has made DIY audio equipment using the Teensy before, and this time he wanted to try making an LED audio meter using a combination of the StereoPeakMeter example in the Teensy audio library with the FastLED library by Dan Garcia.

Toussaint’s helpful project post on the PJRC forum has a components list, his code, projects images and some great bonus information in a follow up comment from Rob Soles, the person behind the AudioPeak object.


Retrofitted Rodgers 32B Organ

John Kinkennon has retrofitted a classic Rodgers 32B organ using a Teensy 3.6 and custom hardware console.

John Kinkennon retrofits old organ consoles with new hardware, allowing them to be used with virtual pipe organ software such as Hauptwerk, Miditzer, or JOrgan. He used a Teensy 3.6 to retrofit a classic Rodgers 32B console, a process involving building custom hardware for the audio encoder, including input boards for pedals, stop tabs and pistons.

Kinkennon’s Rodgers 32B retrofit uses the Teensy 3.6 and plenty of chained 74HC165N shift registers. It has eight analog inputs plus eight GPIO open collector outputs which Kinkennon uses to control solid state relays that turn on audio power.

Kinkennon has helpfully provided code, schematics and other useful information for a number of his projects on his website. You can also find details about another one of his Teensy organ projects, a MIDI message receiver, on the PJRC forum.

Bionic Arm Exoskeleton using Pneumatic Muscles

James Hobson, better known as The Hacksmith on YouTube, has created a Bionic Arm Exoskeleton that features a Teensy 3.5 at the heart of its 86-component controller board. It is a fully functioning pneumatic steel arm based on the “nanosuit” from the first-person shooter Crysis.

In Crysis, the nano-muscle suits are worn by soldiers to increase their physical strength, speed, agility, and ability to defend themselves. In a video posted to his channel, Hobson and team walk us through the process of designing one part of the suit, a bionic arm, as a demonstration of the process needed for creating a full-body suit.

In a post on, Hobson further describes the research that went into the project including examining existing Pneumatic Artificial Muscle (PAM) systems that have existed since the 50s and comparisons to human musculature systems. Hobson also shares the schematic for the circuit for those who are curious to try their hand at the project.

Hobsons other projects include light sabers, the thermal vision helmet from Predator, and Wolverine claws. If you’ve been wanting to take your cosplay to the next level, his channel is worth checking out!

Sound Generation Board

This audio utility board was designed by Arthur Sobel to facilitate the construction of simple audio devices, and is showcased on on

On this board you will find a footprint for the Teensy 3.2 , a single channel PAM8302M speaker amp, MicroSD breakout board, and connectors for keyboard, switches and pots. It’s based on the NXP ARM Cortex M4 MK20DX256VLH7, which has AnalogIO with one DAC pin. It runs at 72Mhz, using a modified  MPR121 test library.