Blog Posts

Ledmasters has created a chronograph for measuring bullet speed, using a Teensy 4.0 connected to an Adafruit Feather M0 via RFM69 433MHz radio modules.

Stats are displayed on a 3.2″ TFT display, and can be printed via an integrated thermal printer. Piezos attached to PET film are used to measure the bullet strike and elapsed time over a 12″ span. More information about the project can be found in the original forum thread.

Rune Kyndal turned his 1990s era plamtop into a functional Linux machine jamming a Teensy LC, USB hub, and Raspberry Pi Zero W into the small space created by gutting the original electronics.

The HPi95LX (get it? Pi?) crams a 4.3″ 800×480 color LCD (up from 240×128 monochrome!), stereo speakers and USB mic, two USB ports, a full-size Ethernet jack, DE-9 RS-232 serial, and more into this diminutive form factor.

The Teensy is connected to the keyboard membrane to convert it to a USB keyboard for the Pi. Read more on the project’s Hackaday page.

Lazer Tag infrared gun system was one of the hottest new toys in the 1980s, with Tiger’s Lazer Tag Team Ops (LTTO) attempting to build on the franchise in 2004. Fast-forward another couple of decades, and Daverlee brings another great leap forward with his Teensy-based overhaul of the LTTO hardware.

With gameplay based on the Halo series, each gun contains a Teensy 4.1, LiPo battery and charging in place of the original AAs, a color ST7789 LCD substituting for the original monochrome display, a class-D amplifier and vibration motors for audio and haptic feedback, an RFM69 radio for communication, and NeoPixels to indicate team alliance and player number, as well as damage.

Adafruit’s Circuit Playground Express powers base stations, with RSSI-based “radar” to determine player position and weapon range. More information can be found on the project’s Hackaday page.

Continuous Wave or “CW” is a simple way to transmit Morse code over radio waves, and is still popular today, including in the form of contests, where enthusiasts race to generate codes as quickly as possible.

In addition to these encoding activities, decoding is also necessary if you want to understand what was transmitted, which is where PJRC forum member pd0lew’s CW decoder project comes in handy.

The project is based on a Teensy 3.6 + Audio Adaptor Board, with additional automatic gain control (AGC). Once the signal is decoded, it is output to an RA8875-based TFT LCD via SPI, which can accommodate five lines of text, and it can also be read over USB. A custom CNC-machined PCB ties it all together inside an attractive aluminum enclosure. Find out more on the CW monitor project page, or in the video below.

Before this final version housed in a beautiful enclosure, earlier versions were made without any case, and with a milled PCB and die cast enclosure.

In this video the older version can be seen and heard (starting at 0:47) displaying the Morse Code.

Noisio is a kit maker of minimalistic audio kits inspired by classic circuits like the Atari Punk Console. Funkstern Plus radio art object is the latest example of this design maxim.

The Funkstern Plus is bespoke project combining synthesizer, FM transmitter, audio player and 7-channel stereo mixer. It was commissioned by the Rundfunkorchestra for the Bauhaus University Weimar “Archiv der Moderne” collection.

The instrument is also used by the Rundfunkorchestra in live shows, and recently won the Saxon State Prize for Design 2023 in the Digital Design category. More information can be found on noisio’s blog, as well as in the video below.

While attempting to understand the mess of wires that is the Apollo-era space program Up-Data Link Confidence Test Set, Ken Shirriff decided to automate the manual probing process with an automatic connection tracing system that he calls the Beep-o-matic.

Ken Shirriff’s blog is a veritable smorgasbord of fascinating in-depth retrocomputing content, and he also documents his work extensively on Twitter. His reverse engineering of the Apollo Guidance Computer is a particularly fascinating project, and it is here that our humble Teensy 4.1 comes into play!

By combining three 16-bit PCA9555A GPIO chips with the appropriate connectors and a Teensy 4.1 over I2C, Ken can scan through all 47 pins in under a second, rather than laboriously listening for a multimeter beep while probing each manually.

A couple of Python scripts capture and process the output, and voila, you have … an extremely specific tool that is unlikely to be of use to anyone else on the planet? However! The same concept could certainly be applied to other reverse engineering problems, so take a look at the project details and code on GitHub, and let us know if you end up adapting the idea for other uses!

This device from AlexRH really caught our eye: the RH Electronics Nuclear Pioneer Multichannel Analyzer (MCA) Gamma Spectrometer. Based on the Teensy 3.5, the MCA can function as both a gamma ray spectrometer and a scintillation counter survey meter.

Gamma spectrometers work by detecting gamma energy from radioactive decay via a scintillation probe. The MCA can detect radioactive elements and automatically identify isotopes on a range of 32keV-3000keV.

With high-voltage regulated power module featuring an adjustable output of 600-1000V, the device can be connected to an external photomultiplier tube, plus has a 400V regulated power supply for an internal Geiger counter.

Read more about its capabilities on the RH Electronics web site, or check out the video below for a detailed demonstration.

Connecting to the Commodore 64 or 128 expansion port like a “normal” cartridge, TeensyROM from Sensorium adds ROM emulation, Internet, and even USB MIDI to some of the 1980’s most popular 8-bit machines.

We love seeing Teensy boards being used to give old hardware new superpowers, and the TeensyROM is a fantastic example of this!

TeensyROM emulates ROMs loaded from a USB thumb drive (via USB Host port), the Teensy’s mSD slot, or internal flash. USB Host is also used for MIDI in/out, allowing you to for example play the C64’s legendary SID chip with a MIDI keyboard using Cynthcart software.

An RJ-45 jack means you can connect to your favorite Telnet BBS via 38.4k modem emulation, as well as update system time using an Internet Time Server, like modern OSes. You can even load games via NFC tags, as shown in the video below! Source, schematics, and more can be found on the project’s GitHub repo.

We’ve seen Teensy boards in rockets, satellites, and more, but the first step of getting space-bound is developing a reliable engine.

Georgia Tech’s student-run Yellow Jacket Space Program enlisted three proud Teensy 3.6s in their mission to develop a liquid oxygen/kerosene rocket engine, the YJ-1S.

The first Teensy is used as a switchboard to control individual valves within the engine, as well as initiate engine startup and firing sequences. The engine controller uses another two Teensy boards to communicate with the switchboard and take control of the engine valves once initiated.

The results in the video below speak for themselves, and demonstrate the engine meeting its 790 pounds of force thrust target.

PJRC forum member pgi has created an impressive Teensy LC-based MIDI foot switch controller named BigFoot.

The elegant stacked-PCB system features eight assignable footswitches, bank selection, two expression pedal connectors with TRS/RTS switch, USB MIDI in/out, and MIDI DIN out.

Plan is to later build a full enclosure that will strengthen the structure.

Source code, schematics and BOM can be found on GitHub.