arduino to audio

Projects General Guidance
1

I have a small pair of computer speaker (with amp) I ripped apart. I am now running it on my robot with batteries. I was able to plug in music to the standard jack but also wanted the Arduino to be able to play tones through it, so I ripped the cable apart, the picture below is what I have from it. I already tried to attach the red wire to a digital pin and the uncovered wire to ground and played a tone, it worked, but now I want to put music through at the same time. Now I don't know too much about audio such as the volts going through and such but I wanted to know what the best way to do this with out having negative voltage destroy everything.

  1. best way to attach to Arduino?
  2. can I connect the grounds (2 uncovered wires) of the 2 main wires together?
  3. can I connect the grounds of the cable to the Arduino's ground?

2012-07-22 20-24-36.066.jpg
2012-07-22 20-24-36.066.jpg2560×1440 366 KB

2
  1. best way to attach to Arduino?
  2. can I connect the grounds (2 uncovered wires) of the 2 main wires together?
  3. can I connect the grounds of the cable to the Arduino's ground?

1 . Put a resistor between digital output and red wire, you can tide white and red together, probably they correspond to left right channel.
2 Yes, you can. Most likely, they connected on the amplifier board, so if you can, post a picture to make sure.
3. Yes, you have to.
Arduino outputs about 2.5V rms, which is almost 10 times more than regular player at line-out or head-phone outputs. To sum up two signals, music and tones, you should mix them up aproximately in same proportion, setting resisror divider 10:1

3

I think I would also want to capacitivly couple the digital pin to the speaker.