diy iPhone 3G charging/lineout Adapter

DC Dave · 30th November 2008, 01:18 AM

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=N...rticle&sid=696

Sparkfun supplied the dock adapter.
http://www.sparkfun.com/commerce/pro...roducts_id=633

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

DC Dave · 30th November 2008, 01:20 AM

The size of the dock connector allowed the resistors to be housed within.

It works great, and only cost $5.

CptanPanic · 2nd December 2008, 01:50 AM

How did you wire up the line out? Have you verified the line out works while charging?

DC Dave · 2nd December 2008, 02:20 AM

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.

DC Dave · 3rd December 2008, 01:48 AM

Okay, the iphone charges, but no line out. I'll do some more research and see what needs to be changed. Could be a different pin out compared to other iPods. Or something additional might be needed.

CptanPanic · 3rd December 2008, 01:54 AM

Yes please let me know. I have read others having to put into airplane mode, etc. Also let me know if you get any cell phone interference.
Thanks,
CP

CptanPanic · 3rd December 2008, 02:12 PM

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

DC Dave · 4th December 2008, 01:30 AM

From what I have read on Head-Fi, it sounds like pin 11 needs to be tied to ground to get the line out to work.

CptanPanic · 4th December 2008, 01:11 PM

If you look at http://pinouts.ru/Devices/ipod_pinout.shtml pin 11 is serial ground. I wonder if you need something on pin 21, like the 1MOhm resister that the belkin had.

CP

temp123456 · 10th December 2008, 02:17 AM

Hi all,

Did you guys manage to charge + line out the iPhone 3G at the same time? (did you get it to work without the warning message?)

Thanks

10th December 2008, 02:17 AM	#10
temp123456 Account disabled at member's request Join Date: Dec 2008	Did it work? Hi all, Did you guys manage to charge + line out the iPhone 3G at the same time? (did you get it to work without the warning message?) Thanks

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
charging capacitor	joeyd71	Car Audio	4	4th April 2009 08:24 AM
Blaupunkt lineout pin-out	harrygrey382	Car Audio	2	12th September 2008 10:11 PM
Help with charging Li-ion cell	EWorkshop1708	Power Supplies	14	29th May 2008 03:59 PM
Roland Cube 30 lineout mods.	papparay	Instruments and Amps	1	13th October 2005 08:44 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

2nd December 2008, 01:50 AM	#3
CptanPanic diyAudio Member Join Date: Nov 2003 Location: WPB, Florida	How did you wire up the line out? Have you verified the line out works while charging?

2nd December 2008, 02:20 AM	#4
DC Dave diyAudio Member Join Date: Feb 2004 Location: Washington DC	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.

3rd December 2008, 01:48 AM	#5
DC Dave diyAudio Member Join Date: Feb 2004 Location: Washington DC	Okay, the iphone charges, but no line out. I'll do some more research and see what needs to be changed. Could be a different pin out compared to other iPods. Or something additional might be needed.

3rd December 2008, 01:54 AM	#6
CptanPanic diyAudio Member Join Date: Nov 2003 Location: WPB, Florida	Yes please let me know. I have read others having to put into airplane mode, etc. Also let me know if you get any cell phone interference. Thanks, CP

3rd December 2008, 02:12 PM	#7
CptanPanic diyAudio Member Join Date: Nov 2003 Location: WPB, Florida	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

4th December 2008, 01:30 AM	#8
DC Dave diyAudio Member Join Date: Feb 2004 Location: Washington DC	From what I have read on Head-Fi, it sounds like pin 11 needs to be tied to ground to get the line out to work.

4th December 2008, 01:11 PM	#9
CptanPanic diyAudio Member Join Date: Nov 2003 Location: WPB, Florida	If you look at http://pinouts.ru/Devices/ipod_pinout.shtml pin 11 is serial ground. I wonder if you need something on pin 21, like the 1MOhm resister that the belkin had. CP

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)