First, you should download Stacy and compile it:

wget http://www.corbac.com/Data/Sources/stacy_0.1.3.tar.gz
tar -zxvf stacy_0.1.3.tar.gz
cd stacy_0.1.3
make

In the current working directory, you'll find a "Data" folder which contains the save file (stacy.save), the input dump for playback (input.dump) and the audio input source (sample.raw). Two demo files (a dump and the corresponding save file) are provided.

Stacy doesn't support real-time audio input yet, so the audio input is provided in the form of an "input source". It is a raw 48000 KHz stereo audio file. You don't need one to run Stacy, but it will come in handy later. You can use sox to create it from your own media library:

sox some_tune.mp3 -r 48000 sample.raw

Once that's done, place your two launchpads side by side. The left-hand one has to be rotated 90° counter-clockwise. This provides a nicely symmetric setup for working with both hands. Then plug them via USB, starting from the right-hand one and run Stacy:

./stacy

At that point, you should get green lights on the left and a yellow light on the right. If not, check your MIDI connections with

aconnect -ol

note: upon restarting the program, both launchpads often are unresponsive until the "right key" is pressed. Thus I always start my session by pressing any square button and then the "session" button on both launchpads.

You can now test the audio output, for example by playing the provided demo: press button F0 while holding down I0 to launch the dump playback (see the next section for the keys). Audio should come about 5 seconds into the playback. Stacy will cleanly crash at the end of the playback, but feel free to kill it at any time with ctrl+c.