The PicoStorm is actually a full-featured PicoFX controller that is shipped with a storm program and audio as the Ambient track.  This allows it to play over and over again without having to be triggered.  
Sometimes it is desired to be able to trigger the storm to start playing when triggered by a mat or a motion sensor.  Follow these steps to configure the PicoStorm/PicoFX to to that:
  1.  1) Put the SD card in your computer.
  2.  2) Open the /FI-115/AMBIENT folder
  3.  3) Copy the files in that folder (they are 000.BIN and 000.MP3)
  4.  4) Open the /FI-115/INPUT1 folder
  5.  5) Paste the two files into this folder
  6.  6) Go back to the /FI-115/AMBIENT folder and erase the files that are in there (000.BIN and 000.MP3)
  7.  7) Put the SD card back into the PicoFX

To play the storm you will need to trigger the PicoFX.  The trigger only needs to be momentary.