iPhone 4 cable (audio and charge car connection)
I think this kind of information should be easily found on the net, but honestly, I could not find precisely what I wanted.
I just bought an iPhone 4, and I want to connect it to my car radio by using a connector which is on the back of the stereo, and to charge it up with the car battery. Theoretically the things are quite easy: the connector has 6 pins, but I only need three: ground, left and right speakers.
I found the pinout on:
Apple iPod, iPad and iPhone dock Connector Pinout - AllPinouts
I suppose I need to connect the right speaker to pin 3, left to pin 4 and ground to pin 2 (do I need to connect to the other grounds?)
I then plan to get the 12V from the battery and to send them to a usual USB car converter (which steps down from 12 to 5V), and apply the 5 volts to the pins 23 and 16 (the two grounds do not have to be connected, right?)
Then, should I put a 68k resistor on pin 21? the resistor needs to be between pin 21 and ground (and which ground)? What if I don't use this pin at all, which message comes out on the iPhone?
If all of this is already explained somewhere else, could you please tell me where?
Thank you very much