SparkFun MP3 Trigger Input Voltage Range: 4.5V to 12.0V DC, or regulated 3.3V (jumper selectable). Current Consumption: Approximately 45mA idle, 85mA playing Media: SDSC and SDHC microSD cards File system: FAT32 and FAT16 Audio output: Headphone stereo (1/8 stereo jack) Trigger inputs: Logic level 3.3V5.0V, active low inputs, w/ internal pull-ups (connector provides individual grounds, allowing switches or jumpers to be connected directly to each trigger input) Serial: Full duplex, 8-bit, 38.4Kbaud (default, other baud rates supported via initialization file)