The heart of the MP3 Trigger board is the Cypress PSoC CY8C29466-24SXI microcontroller which serves up MP3 data to a VLSI VS1063 audio codec IC. This version also supports an optional initialization file that can be used to set the serial port baud rate as well as to reprogram any of the 18 trigger inputs to alternate functions, including random and sequential track selection, transport controls and even volume up/down. Each conventional trigger can be set to either allow immediate restarts, or to lock out restarts if audio is playing. Also, a new trigger filename convention provides greater flexibility in naming your MP3 tracks and makes file management easier.

There is also a “Quiet Mode” feature that can be enabled via the serial control port. In this mode, the trigger inputs don’t start tracks directly, but instead produce a serial message indicating which triggers were activated. A host microcontroller can thus monitor the trigger inputs and then start any track or sequence of tracks via the serial control port, making the triggers much more flexible.

This version of the MP3 Trigger includes firmware that supports the use of an initialization file on the microSD card that can be used to change the serial baud rate, as well as to repurpose any of the 18 trigger inputs to alternate functions, such as random and sequential triggers, navigation controls and even volume controls. In addition, a restart lockout option can be used to prevent any trigger from starting a track if audio is already playing. Using these features, custom applications can often be implemented without the use of a separate microcontroller.

Features

• Input voltage range: 4.5 V to 12.0 V DC, or regulated 3.3 V (jumper selectable)
• Current consumption: approximately 45 mA idle, 85 mA playing
• Media: SDSC and SDHC microSD cards
• File system: FAT32 and FAT16
• Audio output:1/8″ (3.5 mm) stereo headphone jack
• Trigger inputs: Logic level 3.3 V to 5.0 V, active low inputs with internal pull-ups (connector provides individual grounds, allowing switches or jumpers to be connected directly to each trigger input)
• Serial: full duplex, 8-bit, 38.4K baud (default, other baud rates supported via initialization file)