Disclaimer:I make no warranties about this information. You must verify all
work that you do, I cannot. I also cannot guarantee that voltage spikes, dips, etc from
your car won't cause damage. (perhaps with some diodes for over-voltage protection, and adding a 12V capacitor
to smooth things out). This description is intended for those knowlegeable about
soldering and using a mutlimeter. If you do not know how to do such things, then I'd suggest
buying one of the available 3rd party pre-made adaptors instead.
Further warning: This work involves de/soldering what would appear to be
smaller than 30-gauge stranded wire. I've done fair amt of rework in the lab over the years, and
still all I can say about this was yuck!
If I had this to do over (and I might), I'd lean toward buying a pocket-dock (instead of
the Apple Dock-to-Firewire cable), rewiring the presumed 6 wires inside of it, and making
a male-firewire to power/audio cable instead. Reasoning... I presume the pocket dock is
larger, and would have more room for better wiring. Plus the wires in the Firewire
cable are VERY thin.
Note: This cable does NOT work with the Dock. ie.. I don't think the
Dock is wired to pass the line-out signals thru.
Full power/audio cable for iPod
A single-cable, full power/audio cable (using the line-out signals on the 3G iPod)
had been on my list of things to do since I got my iPod back in the spring (when no such
3rd party accessories were available), but I just finally got around to it thanks to
our hardware group at Ericsson getting laid off (and thus a lot of free time) :-)
I also posted instructions on a power-only cable that works
with the Dock. This 1st cable was a stepping stone for me.
- Apple Dock-to-Firewire cable (will be rendered useless for its normal task, altho perhaps not for
PC and USB2.0 users.. hmmm...)
- Soldering iron
- Car cigarette-lighter male plug (optional) (available from places like Radio Shack)
- For the line-out audio connection: 1/8" female stero jack. I bought a headphone "extender" cable with an attenuator in it. I made my cut between the attenuator and the male end giving me an added way to drop the line-out volume (which I find a bit too high for my tape adaptor in my car).
- for the power connection: any 3' entension cable with both a male and female end. I bought a mono 1/8" cable.
- Steady hands
- Wire strippers
- Electrical tape
- Rubber cement, or some such glue to hold fragile wire solder joints once done
I used this diagram of the Firewire pin-out
as a reference, and verified all of my work using a voltmeter.
Dock side of the connector
- Use a small screwdriver to pry open the front corners of the Dock connector on the cable. I was not
able to open my connector in a non-destructive way, and ended up wrappig it once in electrical tape
to hole the plastic cover on, and the "release" push tabs in place (you can still apply pressure to
the side buttons thru the tape).
- For me the side with the small Dock icon peeled away, and the other side (no icon) pushed back.
- Use a small screwdriver again to pry open the metal casing at the rear... as I lifted the tabs
the case started to open.
- I found that the part without the tabs slid backwards and off.
- Inside I annoying found that the unused pins (that I would need) were cut short on the connector and that
all of the pins were gooped with glue. I used my small screwdriver and found that the glue pried
away easily, but with some patience.
- I found 6 wires connected to the 2x15 inside connector. 6 were connected on the same row
(which is the odd pins), and 2 were jumpered to both the top and bottom rows (firewire power/gnd... altho
I wonder if the jumper on the power is a sense pin or something).
- Black: connected to pins 1&2 (firewire GND) (keep this)
- Thicker Silver: connected to Firewire +12 (keep this)
- Thin blue: pin 3 (will re-use for line-out L)
- Brown: (will re-use for line-out common)
- Thin Green: pin 7
- Thin Red: pin 9 (will re-use for line-out R)
- Mark the side of the connector that has the odd pins (1,3,5,...27,29). This is the row
that currently has most of the wires connected.
- De-solder the blue, brown, and red wires.
- Orient yourself with the connector. The row that you removed the wires from, and still has
the green wire connected is the tow of odd pins (plus your mark).
- Re-solder the brown wire to pin 29 (last pin on odd side)
- Re-solder the blue wire to pin 27 (next to brown wire)
- Flip connector over and re-solder red wire to pin 28 (2nd from end.. under pin 27)
- Check for shorts between all of these pins.
- You may want to wait to do the other connector, then afer testing, coat with rubber cement
to lock pins in place. Re-assmeble connector.
Here I guess you have a bunch of choices... essentially you have 5 wires that you care about,
power, GND, line-out(left, right, common). You could choose just about any kinds of connectors you
wanted, or just wire these directly to a stereo wiring harness, etc.
I chose to run my line-out audio to a 1/8" female stereo jack. For the moment I will plug
cassette CD adaptor into this as my method of getting the sound into my car stereo. At some
point down the road, I can update to a Blitzsafe (or equivalent) adaptor to run the sound directly
into my head unit, and all I should need to do is buy a commonly available
1/8" stereo to RCA-plug cable.
For the power, I attached a 1/8" mono plug (only need 2 signals here, not 3 as you would get
with a stereo plug, which helps me not confuse the two). I took the other half of the "extender"
cable, and attached that to a cigarette lighter adaptor. When I have a bit more time I will instead open up the dash and
connect to a permanent 12V source, having the female side of the 1/8" mono jack for my cable to plug into.
- Cut the Firewire connector off of your dock cable, and strip back 3 inches of the outer white sheathing.
- You'll find a silver wire, black wire, a lot of thread, and 2 "pairs" of shielded wires, all inside
a shielded braid of wire.
- CAREFULLY remove the inner/outer sheaths from the section you need to work with to expose the blue, red, brown wires.
- Solder the Black and Silver wires to your choice of power connector (for me the 1/8" mono male plug)
- Solder the Blue, Brown, Red wires to your choice of audio connector (for me, the 1/8" stereo female jack with attenuator).
- Create a power connection in your car (for me, I made a cigarette adaptor to 1/8" mono female jack) (as a good practice,
since this lead may be hot, you should make it a female jack, not a male plug, that way you can never accidently
touch the "hot" part).
Putting it all together
When I done, I made the following connections
- Insert cassette adaptor into car stereo
- Turn on iPod
- Plug modified Dock cable into iPod
- Plug male end of casetter adaptor into the female 1/8" stereo jack on modified cable, and adjust attenuation to taste
- Sound is indeed coming out
- Plug cigarette adaptor in to car
- Plug male 1/8" mono plug from modified Dock cable, into the female 1/8" mono jack from the cigarette adaptor
- Verify that your iPod battery icon changes to the "charging" icon
- Do a little dance, and have a beer in celebration
iPoding.com pic of the Dock connector with pinout information.
As desribed above, I hooked it up in my car, and all appears to work well. Since I can't use the Dock anymore
I will prob buy a holder such as this, and bury
all of the cables behind my dash, having only the Dock end of the modified Dock cable coming out into view.
I haven't tested yet to see if I got Left/Right correct yet. Then again, I'm not sure that it would make a
difference for anything I'd ever listen to over my iPod.
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