DORKBOTPDX November Workshop: Microcontroller based audio!

RSVP Required, email to  Limited to 15 people.

This hands-on microcontroller audio workshop will show you how to use a Teensy 3.2 and codec chip to generate and playback CD quality sound, and process and analyze audio in real time.

Instructor: Paul Stoffregen

Sunday, November 1st, 1-5pm at
Free (Donate to Ctrl-H if possible!) All ages! 

DORKBOTPDX October 2015 Workshop: Build Your Own Teensy MIDI Device!



The Build Your Own Teensy MIDI Encoder Workshop will show you how to use a Teensy 3.1 to create a MIDI encoder that sends MIDI OUT messages over the Teensy's micro-B USB plug.

During the workshop, you will build a serial-to-parallel, parallel-to-serial switch matrix using a Teensy 3.1, a breadboard, IN4148 diodes, and reed switches (if you wish to validate the switch matrix). Darin will demonstrate how to write the switch matrix scan code and how to encode the simulated keypress signals into MIDI OUT messages using the Arduino/Teensy Keypad and MIDI libraries. Extending the code to accommodate MIDI IN, velocity sensitivity and other MIDI messages, as well as using shift registers (74HC595 and 74HC165), will be discussed.

Recommended hardware and software for the workshop:

We will have some extra supplies available.
Instructor: Darin Molnar
Sunday, October 25, 1-5pm at
Free (Donate to Ctrl-H if possible!) All ages! 

DORKBOTPDX September 2015 Workshop: Oregon Lawnmower Massacre

Unfortauntely this workshop has been post-pwned due to mechanical issues, please come to Ctrl-H for a free Open Lab Sunday September 27th instead!

In this workshop we will build a "kicking legs" Halloween prop.  These props are normally put under lawnmowers to simulate a lawn care accident.  This project is based on a project by "Scary Terry", you can see the original here.  We'll play with linkages, servos, and microcontrollers.
Here's a quick video of the mechanism (not final though). 

  • Laptop with Teensyduino installed
  • Phillips head screwdriver (electric is probably best)
  • 2 wrenches, either 7/8", 11 mm, or adjustable
  • A pair of socks, old shorts/pants, fake blood, etc for decoration.
  • $35 for the kit.  Comes with:
  • Optional: Switches / sensors to trigger the kit
RSVP required!  RSVP by emailing
Sunday, September 27, 1-5pm at
All ages!
Donate to Ctrl-H if you can!
Flyer by Jason Plumb

Sturdy Pots on Breadboards

Submitted by paul on Fri, 2015-08-14 19:36

Often I throw together a quick demo for the bi-weekly DorkbotPDX meetup, usually involving one or more pots to adjust parameters.  Finally, I've come up with a pretty good way to put pots on solderless breadboards.

Click "Read more" for details and the shared PCB....

DORKBOTPDX July 2015 Workshop: Undorked Aerial Vehicles

Rich Burton of HooperFly gives an overview of open source drone/uav projects and flight demonstrations. We'll take a group dronie! 
Here's a link to the slides:
Sunday, July 26th, 1-5pm at
Everyone welcome! All ages!
Free! (Donate a bit to Ctrl-H if you can)
Flyer by: Zach Archer
More links for post:

Teensy Audio Library Gets S/PDIF Support

Submitted by paul on Mon, 2015-06-08 07:21

Thanks to the amazing effort of Frank Boesing, the Teensy Audio Library now has native S/PDIF output.

Using a $1 TOSLINK connector, or just a red LED, you can get optical S/PDIF digital audio output.

Optical output is useful for projects where Teensy connects to grounded equipment.  There are lots of ways to simply play sounds, but the Teensy Audio Library gives you Arduino-sketch controlled synthesis, mixing, effects & filters, analysis and much more.  Sketch controlled sound is most useful when you connect more hardware to Teensy & use other Arduino libraries for inputs.  But often that other hardware comes with ground connections that cause audio-corrupting ground loop problems with analog audio, like the DAC pin or the audio shield.  Optical S/PDIF give you perfect digital audio output for those projects!

Click "Read more" for much more detail about the S/PDIF development....

Ten Watt RGB LEDs

Submitted by paul on Mon, 2015-06-01 03:25

Spent a good portion of the weekend fiddling with insanely bright 10 watt RGB LEDs.

Trying to make very low-cost DMX protocol control, of course for a Burning Man project that's planning to use 150 of them!