Mint Box Enclosed MP3 Player

The MP3 player project utilizes a PIC18LF452 microcontroller which sends data to STA013 MP3 decoder chip and handles flash card interface.

A 3.3V Li-Ion battery is used to run the project where the decoded digital audio is converted to analog by CS4340 DAC. To allow using different batteries like AA Alkaline, the MP3 player uses a MAX756 DC boost regulator. There is an optional FM transmitter MAX2606 in order to get rid of cables while playing music through car radio receiver. The USB connectivity makes it possible to download/upload files and even charge Li-Ion battery through MAX1811.

The PIC18LF452 microcontroller runs at 20MHz and makes the MP3 player a standard mix of high power 8-bit microcontroller and ASICs. Its other functions include navigating the FAT16 file system although it ignores long filenames & loading MP3 files and communicating to the flash card. The PIC reads and writes the compact flash card, reads button presses, and configures/runs the STA013 MP3 decoder chip.

An I2C port is used to control the MP3 chip for setting the volume/bass/treble, getting the current MP3 data, uploading new firmware, and others. The FTDI232BM is the USB to serial chip.

Rest of the project