Initialize a new Launchpad. If there are no currently connected Launchpad device, initialization will fail with an error. You can fake a device by creating an input and output MIDI device and name them as Launchpad.

if pad, err = launchpad.Open(); err != nil {
    log.Error("error while initializing launchpad")
}

// turn off all of the lights
pad.Reset()

Light buttons

pad.Light(0, 0, 3, 0) // lights the bottom left button with bright green

The coordinate system is illustrated below.

+--------- arrow keys -----------+  +--- mode keys ---+
{0, 8} {1, 8} {2, 8} {3, 8} {4, 8} {5, 8} {6, 8} {7, 8} | ableton
----------------------------------------------------------------
{0, 0} {1, 0} {2, 0} {3, 0} {4, 0} {5, 0} {6, 0} {7, 0} | {8, 0} vol
----------------------------------------------------------------
{0, 1} {1, 1} {2, 1} {3, 1} {4, 1} {5, 1} {6, 1} {7, 1} | {8, 1} pan
----------------------------------------------------------------
{0, 2} {1, 2} {2, 2} {3, 2} {4, 2} {5, 2} {6, 2} {7, 2} | {8, 2} sndA
----------------------------------------------------------------
{0, 3} {1, 3} {2, 3} {3, 3} {4, 3} {5, 3} {6, 3} {7, 3} | {8, 3} sndB
----------------------------------------------------------------
{0, 4} {1, 4} {2, 4} {3, 4} {4, 4} {5, 4} {6, 4} {7, 4} | {8, 4} stop
----------------------------------------------------------------
{0, 5} {1, 5} {2, 5} {3, 5} {4, 5} {5, 5} {6, 5} {7, 5} | {8, 5} trk on
----------------------------------------------------------------
{0, 6} {1, 6} {2, 6} {3, 6} {4, 6} {5, 6} {6, 6} {7, 6} | {8, 6} solo
----------------------------------------------------------------
{0, 7} {1, 7} {2, 7} {3, 7} {4, 7} {5, 7} {6, 7} {7, 7} | {8, 7} arm
----------------------------------------------------------------

Read/listen for touches

hits, err := pad.Read() // reads at most 64 hits
for _, hit := range hits {
    log.Printf("touch at (%d, %d)", hit.X, hit.Y)
}

// or alternatively you can listen for hits
ch := pad.Listen()
hit := <-ch

Close

Close your input and output streams once you're done. Likely to be called on graceful termination.

pad.Close()

Demo: Light your touchs

A demo

A simple program to light every touch:

pad, _ := launchpad.New()
pad.Reset()

ch := pad.Listen()
for {
	select {
	case hit := <-ch:
		pad.Light(hit.X, hit.Y, 3, 3)
	}
}

License

Copyright 2013 Google Inc. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.