Here's a demo video of where I am with the development of my looper module, which uses a Teensy 3.5 (and a PIC chip). Loops are recorded to the SD card, so length is virtually unlimited. Also supports overdubbing. Build information and source code available here http://www.cutlasses.co.uk/tech/loop...on-1-complete/

https://youtu.be/Ur3xYh8PTQg