The Akai APC40 is a great controller for MIDI mapping to applications (Traktor, etc.) as it has a large and varied set of controls available, along with multi-coloured pads. For a MIDI application to take full advantage of these the APC40 needs to be in Firmware Mode 1; upon power-up, however, the APC40 enters Firmware Mode 0. Switching to Firmware Mode 1 can be done by opening Ableton Live, waiting for the APC40 to be recognised as a control surface (assuming it is configured as one), and then closing Live. apc40-mode is simple utility that will let you switch between the three firmware modes at the command line, so you don’t have to open Live (or even have it installed).
In Part 1 of this post, I explained the background of this project. Now I’m going to detail the hardware and software development setup I am using.
N.B. Since starting this series, Traktor 2.6.2 has been released, which allows MIDI mapping of the Remix Decks. I’ve decided to finish this series anyway, however, as it has a lot of information that is helpful for Arduino development in general, as well as for building custom controllers for the Remix Decks (and other HID and MIDI applications also).