apc40mk2

CDJ-style looping control mapping for the APC40MKII ableton midi controller

prerequisites

download release.zip from https://github.com/diracdeltas/apc40mk2/releases/latest
unzip it
copy the unzipped apc40mkii_azuki folder to your Ableton MIDI remote scripts directory using the instructions at https://help.ableton.com/hc/en-us/articles/209072009-Installing-Third-Party-Control-Surfaces. for instance on Mac with Ableton 10, this would be /Applications/Ableton Live 10 Suite.app/Contents/App-Resources/MIDI Remote Scripts.
open Ableton Preferences with your apc40mk2 plugged in and select apc40mkii azuki as the control surface.

the custom mappings are as follows. note that all clips must be warped for this to work.

METRONOME - sets the loop start point to the nearest bar of the current playing position. if already looping, this turns off looping.
TAP TEMPO - sets loop end point to the nearest bar of the current playing position and engages looping.
NUDGE- - moves entire loop left by a bar
NUDGE+ - moves entire loop right by a bar
SHIFT NUDGE- - halves the loop length
SHIFT NUDGE+ - doubles the loop length. note: this will cause the play position to jump unnecessarily sometimes (i think this is an ableton bug)

thanks to will marshall for doing most of the work for LooperComponent in https://github.com/willrjmarshall/AbletonDJTemplateUnsupported.