USB Strat audio conversion & MIDI controller, Teensy 4.0 Inside. Project name: CAMILLE-LYON


The gumstick-sized Teensy 4.0 made this project possible! Fender's iconic Stratocaster's control cavity was routed to accommodate a few analog pots and a dual-pole 5-position blade switch but I've crammed the Teensy, a stereo codec, two RGB LED rotary encoders with pushbutton shafts, a 9DoF IMU motion sensor, an "invisible whammy bar" ToF sensor, and an additional special feature RGB LED (My Flashing Tilefish lamp rests between the neck and middle pickups in the cable tray and offers another degree of status feedback, or just plain chroma morphing fun).

I'm sensing the position of the 5-way switch using the repurposed "tone" pole using the Teensy's interrupt pin features. Since I've replaced the 1950's era high cut passive tone controls with anything-goes rotary encoders, the tone half of the switch was up for grabs.

One channel of the stereo codec captures the mono signal from the selected combination of magnetic pickups, the other is either the neck pickup (allowing all three pickups to be hot when the blade is already selecting the bridge and middle pickup) or an optional piezo bridge sensor, under program control.

I've installed Seymour Duncan noiseless Strat pickups because they come with 4-wire shielded cable which is helpful because if the cavity is shielded like Strats are supposed to be (my Squier wasn't), the magnetometer in the IMU wouldn't work too well. Because both coils are available on board, I can control if they're single-coil or hum-cancelling, which is a huge bonus for tone definition!

I'm not yet using any of the controls embedded in the codec or the amazing drag & drop DSP functions in pjrc's audio design gui, and I haven't had time to access the IMU or IWB functions yet (other than to verify they work), but simply sending MIDI Program changes to VST plug-ins in Reaper turns this in a monster instrument! And I haven't even gone the extra inch to send MIDI continuous controller messages to any of the myriad of VST plug-in parameters from the motion sensors or from the real-time hand distance measurement LIDAR "Invisible Whammy Bar".

I'm using the Reaper DAW in an unorthodox way: The MIDI PC command can enable any number of presets simultaneously and can process each stereo channel separately or together. Because Reaper accepts VSTs from most vendors, the possibilities are staggering!
Apologies. The audio quality of this recording is not great. It’s only my iPhone mic across the room, but this shows how the voice of the guitar can change instantly with a knob twiddle, push, or a switch flip. With 6 static knob colors and 5 switch positions, that’s 180 addressable processing voice presets available at my fingertips, if you’re not using them for something else, 1,080 if you count the feature LED. Leave the heavy, bulky midi pedalboard at home!

Too many creative ways to program the Teensy with these sensors, too few years!