Im in the brainstorming stages of a project that will control sequences insync with music. Here is the plan I've been brewing, i want your guys advice to see if i can get it done. Im going to play a stereo mp3 from an ipod. One side of the track will have the music and the other side of the track will have my "data stream." I would like to feed this data stream into a adc0803-lcn CMOS[SIZE=-1] 8BIT A/D converter. Which takes in an analog voltage and converts it into binary. This ic can take a very small [/SIZE]reference voltage. so if i set the reference voltage to 1v, then i can have 255 different voltages between 0-1VDc representing the digital steps. Where I need the advice is do you guys think i can produce accurate voltages from the ipod headphone jack? If not would any type of op amp configuration "square" up the voltage steps? Any advice is greatly appreciated.