I also realized that we need a better way to connect the audio output of the Coby MP3 player to the Dust circuit board. For the breadboard, we connected a 1/8″ mini phone plug from the output of the MP3 player into the input of the amplifier section.
I want to remove the headphone jack from the MP3 player for our smaller prototype in order to eliminate the bulky plug.
Time for surgery again.
After poking around for awhile with a multimeter to try to figure out how the jack was wired, I gave up and focused my efforts on freeing the SMD jack from the MP3 player’s board. It was easier to diagnose the wiring of the jack once it was off the boad.
Since I was tired, I soldered the wires on the wrong side of the board at first (wasn’t paying attention to the orientation of the USB pins I soldered on earlier in the day).