Monday, January 7, 2013

SnakeEyes Audio Boards

A few months ago, I started work on an audio board for Arduino and Chipkit microcontrollers. I wanted something that could play good quality sound effects and music with a small form factor.

SnakeEyes V0.01

My first attempt was a mash up of an Arduino Pro Mini and the same functional structure of the Adafruit Wave Shield. I wanted something that could play all by itself when given a few commands. The host processor would then be free from the low-level audio generation. Small speakers were to be soldered directly to the board in the space above the SD card. This was not a good design from a manufacturing standpoint and frankly, I am not a huge fan of Atmel microcontrollers. I abandoned the project for a while since I was discontent with the results with this board.

SnakeEyes V0.01 Audio Board (front and back)

SnakeEyes V0.02

As noted in some of my previous posts, I found Lutz Lisseck's SimpleSDAudio library for Arduino that used high speed PWM to generate audio from a streamlined SD library. I have a working port of the library to the Microchip-based PIC32 Chipkit processors. The library is very simple and requires very little hardware to get basic functionality. To get higher quality sound, however, more circuitry is necessary.

V0.02 of the SnakeEyes Audio board was born. This used a completely different form factor and used SimpleSDAudio type hardware rather than Wave Shield inspired hardware. It sports Stereo 16-bit 78.125kHz buffered PWM audio generation when using a Chipkit board. The host processor handles all audio generation. It has a headphone jack and thumb wheel volume control as well as two small speakers. There is also the option to use external speakers.

SnakeEyes V0.02 Audio Board

Check for the next post about future audio boards.


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