In an effort to at least show that the iPhone has nothing on the T-Mobile G1, someone has found a way t make the G1 work with an iPhone/iPod Touch dock. This hack may not be what you expect or anything to look at really, but it does show that this is in fact possible.
The easily recognized iPod dock connector has a very well known pinout so the process was not too hard to figure out. To figure out the pinout of the HTC USB connector he just split open the hands free adapter he got with his T-Mobile Dash. Below is the process outlined to create this converter.
Most of the wires were labeled, “L” “R” “M” ect. It took a bit of fiddling to discover that connecting pin 7 to the audio ground ( pin 8 ) turns on the external audio. Sparkfun sells 30 awg (Gauge) wire wrap wire that is perfect for soldering to the ultra tiny pins on both the HTC ExtUSB connector and the iPod Female connector.
We used pins 1, 2, 3, 4, 16, and 23 on the iPod Female connector. If you gently bend the pins out it makes it much easier to solder, but be careful the pins break easy.
1 & 2 are Ground -
3 is Right Audio +
4 is Left Audio +
16 is USB Ground -
23 is USB Power +5
It is important that you do not mix the audio and power grounds or you can get a nasty hum.
On the G1 side of things the upper half of the connector is a standard mini-usb pinout, the bottom is very different.
We used Pins 1, 5, 6, 7, 8, and 10.
1 is USB Power +5v in
5 is USB Ground -
6 is Left Audio +
7 is marked “AG” on the T-Mobile Dash headset board, connect this one to pin 8 to enable audio.
8 is Audio Ground -
10 is Right Audio +
Now we wire the two connectors together like so:
iPod pin - HTC ExtUSB pin
1 ———— 8
3 ———— 10
4 ———— 6
16 ———— 5
23 ———— 1
Don’t forget to solder together pins 1 & 2 on the iPod side and pins 7 & 8 on the G1 side.
When its done it looks like this:
So we have audio from Audio player and YouTube, and the speaker dock charges the G1 too.