Wednesday, January 7, 2015

Stereo audio player using the PIC32, MCP4822, microSD card and the MDDFS library

Oscilloscope screen capture of output from the audio player
Top - left channel
Bottom - right channel

Using the PIC32MX250F128B, I decided to make a simple audio player. I wanted to play back good quality audio from a large memory space - a microSD card. So, I made this WAV player that can play back 16-bit 44.1kHz WAV files with 12-bit stereo audio output. Of course that's not all it can play back. It is programmed for automatic period configuration so that the period is set on the fly based on the song sample rate. It can play back both 8-bit and 16-bit mono and stereo audio files and I have tested from 8kHz 8-bit mono to 44.1kHz 16-bit stereo. The player itself does not include an audio amplifier to drive speakers but can drive earphones. I've used an external stereo speaker for testing.

The hardware is fairly simple! Using the Microchip Memory Disk Drive File System (MDDFS) library, and my previous work using the MCP4822 dual 12-bit DAC, integrating these components to make a working audio player was quite fun and a good learning experience.

Here I share all my project files and source code, along with documentation regarding this project. Let me know what you think!
Schematic of PIC32-based audio player

Running demo of the audio player:

All project files and schematic can be downloaded from:

Documentation can be downloaded from: