music player shield - independent L/R volume control

I need to play a G major chord recorded in MP3 or WAV. Then I need to very slowly fade to a G minor chord, also on MP3/WAV. The fades back and forth are over about 15 seconds when directed by the Arduino. Stereo not needed.

My idea is to record one chord on the left track and one on the right track. Then play the recording in a player shield and have Arduino slowly change volumes of L up and R down.

I have not been able to find a shield where the vols of L and R can be controlled independently. Anyone know of one? Anyone have an idea for alternate approach?

Thanks.

Hi,

The Sparkfun MP3 shield can set the left and right channel volumes independently, from their sample code:

void Mp3SetVolume(unsigned char leftchannel, unsigned char rightchannel){
  Mp3WriteRegister(SCI_VOL, leftchannel, rightchannel);
}

I’m sure there will be others. Alternatively you could use an external audio/mp3 player into a sheild of your own making with a simple amplifier circuit onboard, and use the Arduino to adjust the relative volumes of each channel, for an example of what that might look like, check this page

Cheers ! Geoff

Thanks for pointer to SF. My other idea was to take the left and right and run each through their own digital potentiometer. Your pointer to the two LM386 looks great. I'll try the SF board first as that looks most sure to work.

Thanks for pointer to SF. My other idea was to take the left and right and run each through their own digital potentiometer. Your pointer to the two LM386 looks great. I'll try the SF board first as that looks most sure to work.