There are three ways you can adjust the volume on the MP3 Trigger.
- Use the INI file to create volume up/down buttons on two free trigger pins.
- Send volume commands with a microcontroller via serial to the board through the FTDI interface on the edge of the board.
- Add an external audio amplifier.
We don't have instructions for adding your own external amplifier but the first two options are covered in the hookup guide that you can find at the link below.