BabyBOOMER Audio Amplifier and Filter Prototype for Arduino/ChipKit

Here is a prototype of one of my circuit boards for the planned BOOMstick Audio board family. This series was introduced in my previous post. It is intended for use with Lutz Lisseck's SimpleSDAudio Arduino library and my port of that library to ChipKit, BasicSDAudio. Really, it should work for any PWM-based audio system, including the Tone library.

Top side of the BabyBOOMER Audio board prototype

Here are the goals I was trying to meet with this board:

• small (only 0.56 sqin)
• breadboard friendly (basic 0.1" headers)
• at least 1W speaker output using 8ohm speaker (efficient class D amplifier)
• easily accessible volume control (right out on top)
• lower PWM noise including buffers, filters, and a pseudo 16-bit mode

Bottom side of the BabyBOOMER Audio board prototype

I did a preliminary test just running the ToneMelody Arduino example sketch with a 4ohm speaker. It was *very* loud for such a small board. I had to run off a battery since my wimpy USB cable cannot reliably supply 5V with the estimated 2W output using a 4ohm load.

Time for some real testing!