Prototype of MultiFX and Looper Pedal (RPi3 and Teensy) : r/diypedals
PJRC (Teensy) Forum
Proto Pedal Example: Programmable Digital Pedal - SparkFun Learn
Introducing JayShoe's Pro Audio Series ADC & DAC Audio Modules for the Teensy 4 and Teensy 4.1 offering high quality audio inputs and outputs for musical instruments, audio mixers, effect processors, guitar
Teensy Audio Part 2: Chorus and Flange Audio Effects - YouTube
Proto Pedal Example: Programmable Digital Pedal - SparkFun Learn