gistfile1.js

GriffinPowerMate.registerInputPackets = function() {
    // The PowerMate only sends one kind of packet, which is 6 bytes:
    //
    //   - Byte 0: pushed (0 or 1). Updates immediately on push or release.
    //
    //   - Byte 1: turn (signed 8-bit value). +1 or -1 for every 3 degrees
    //     or so of rotation. May require turning a few degrees before you
    //     get to the next "tick" (there are no physical detents; the motion
    //     is very smooth). If you turn very quickly, a single packet will
    //     be sent with value of greater magnitude (2 ticks = -2 or +2, etc;
    //     I can get it to go up to about 7). If you turn consistently,
    //     several identical packets will be sent, so we need to take care
    //     to not coalesce "unchanged" values.
    //
    //   - Bytes 2-5: always the same values (0x00, 0x4F, 0x10, 0x00).
    //     Perhaps some kind of device identifer magic. Ignored.

    var packet = new HIDPacket('control', [], 6);

    packet.addControl('knob', 'push', 0, 'B', 0x01);
    packet.addControl('knob', 'turn', 1, 'b');

    // WARNING: Need to hack common script to make this have an effect.
    // Pull request sent in at https://github.com/mixxxdj/mixxx/pull/406
    packet.setMinDelta('knob', 'turn', undefined);

    this.controller.registerInputPacket(packet);
}