Hello, Sebastian.
The following subroutines are examples of how to play a specific MP3 on the MP3 trigger using two different serial trigger commands (which are described in the Serial Control Protocol section of the MP3 trigger’s user’s guide):
# uses the Trigger (ASCII) command to play track 1.
sub trigger_ascii
0x31 0x54 serial_send_byte serial_send_byte
return
# uses the Trigger (binary) command to play track 1.
sub trigger_binary
0x01 0x74 serial_send_byte serial_send_byte
return
Please note that you will have to change the Maestro’s Serial mode to be “UART, fixed baud rate” at 38.4K baud to communicate with the MP3 trigger. Examples of how to call a subroutine if a button is pressed can be found under the “Using a button or switch to control servos” and “Using multiple buttons or switches to control servos” sections of the Maestro’s user’s guide. (By the way, we describe how to use serial under the “Serial output” section of the user’s guide.)
-Jon