Thanks to Weon-sik Nam for sharing this project with us. Check out more here. He writes:
When guitarists play, some of them use effect which is repeating delayed signal. It is called delay pedal. And most of them want to set the delay time rate synced with daw so they can record more accurate sound effect with guiding beats. So I just hacked this analog devices to be synced with daw through arduino teensy board. It uses usbMIDI.setHandleRealTimeSystem(RealTimeSystem) internal function. Only single pc817 opto-coupler is needed for hardware.