diy iPhone 3G charging/lineout Adapter

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
After not finding what I wanted in an adapter for the new iPhone I decided to make one to fit my needs.

I wanted to be able to charge the phone using the usb power adapter in my car and also have a line out for audio.

I used the schematic shown here for the charger portion of the adapter.
http://tzywen.com/modules.php?name=News&file=article&sid=696

Sparkfun supplied the dock adapter.
http://www.sparkfun.com/commerce/product_info.php?products_id=633

4 resistors and two junk-drawer cables was all that was needed.
 

Attachments

  • complete.jpg
    complete.jpg
    80.1 KB · Views: 366
I connected the audio out cable directly to pins 2, 3, and 4 of the dock connector which are the signal ground, right + and left + respectively.

I did not get a chance to test the iPhone with charging and playing at the same time, but my Nano played fine while charging. I'll test the phone and reply back.
 
There is a chance that you won't get it to work. I read around, and it seems there might be some kind of authentication chip needed to tell iphone that it is ok to send line out and charge. Hopefully this is not the case. I took apart my dock and couldn't really tell.
CP
 
Works great with my iPod, but I didn't get the line out to work with the iPhone. At the time this thread was started, there wasn't much on the market, but now there are different adapters and cables to choose from. I'm currently using a Pocket Dock successfully. Not diy, but it works.
 
I just got a dock from amazon that claimed to be for the iphone 3g. I used it for the ipod touch and the touch plugs into it just fine. One problem was that I got a bad hum when listening to music and charging at the same time. I opened the case up and also discovered that the tip of the 1/8 audio jack was being tied together with pins 3, and 4 ( im guessing the audio left and right), the center ring was being grounded, and the ( what should be ground ) back ring on the plug was open and not connected at all.

All I see is one 75.3k ohm resistor connected to ground, and then wires connecting the back plug to the plug going to the ipod touch / iphone.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.