Here are the latest MP3 Trigger download files. Links to the schematics, CAD (Eagle) files, app notes and related datasheets can be found on the SparkFun MP3 Trigger product page.
Release notes: I added one instruction cycle per trigger to the input scanning routine to allow more time for the multiplexer to settle before reading the input. Try this version if you have long wires on your trigger inputs and are experiencing any false triggering.
Release notes: Adds the following improvements to v2.50: Faster startup with lots of MP3 files, control of initial volume, and ability to make TRIG18 a play status output pin. See sample initialization file below for documentation on the volume and play status output functions. Fixed a bug that prevented proper parsing of init file commands when the command section of the file was more than 256 bytes long.
Release notes: Includes documentation for using the options play status output