Wiring

[deyannn]

Hi all,

what sort of wiring do you do on your cars?
On my 9-3 I used just a regular Cat5E FTP cable I had lying around, 1 wire each for Left,Right,RX,TX,GND,+5V with 2 cables not being connected to anything.

I wonder if it will be a waste of money and resources if I use stranded cable for Left/Right/GND instead of the solid cables in the FTP cable. Or wether using 2 cables in a twisted pair instead of one will have negative or positive effects.

Since I'm rather noobish and amateur at electrical works I don't fully understand cable capacity, resistance, how it changes when bi-wiring and what sort of inference can occur from bi-wired twisted pairs  or a twisted pair where 1 solid cable is Audio Reft and the other is Audio Right, etc. Or in cases where some of the following examples come into play (all on regular Ethernet cables ).

Example 1:
Pair 1:Left / Right
Pair 2: RX/TX
Pair 3: DC5+/DC5+
Pair 4: GND/GND

Example 2:
Pair 1: Left / Right
Pair 2: RX /TX
Pair 3: DC+5V/GND
Pair 4: empty

Example 3:
Pair 1:Left / Right
Pair 2: RX/TX
Pair 3: DC+5V/empty
Pair 4: GND/empty

Example 4:
Pair 1:Left / GND
Pair 2: RX/TX
Pair 3: Right /GND
Pair 4: DC+5V/DC+5V

At times when trying to decide something like this I wish I had a degree in electrical engineering or something similar.

[Karlis]

I used a CAT5E cable running from the back of the car to the dashboard. By the time I got to installing CAT5E, I could do it blind-folded. :) Then I installed a RJ-45 coupler in the dashboard:



I myself am an iOS guy, so for the endpoint connection, I made a small patch cable from a CAT5E to a 30-pin breakout connector, to which then I connected a 30-pin -> lightning adapter bought from Apple and was able to control my iPhone5 and iPhone6.

As for the power supply, I could never get it working. I got to the point where it was sorta supplying power to the phone, but the phone was unhappy (it showed that the cable is constantly being plugged in/unplugged from it). I guess iPhone is really sensitive to what current (?) level is being fed into it...

[deyannn]

I don't know about the iPhones as I'm an Android guy but I have the same RJ45 to 30-pin I use to charge and control my old 80 GB iPod Video  and it charges properly.
I think the different devices you can charge have specific needs for the connector to charge properly at least based on
http://pinouts.ru/PortableDevices/ipod_pinout.shtml
and some other data sources.

Sadly the pinouts are applicable for older ipods and iphones and I don't know if you need another setup for Iphone5/6 with the lightning adapter.

The below is taken from pin 27 description in the pinours URL:

USB Data (+)
Pins 25 and 27 may be used in different manner. To force the iPod 5G to charge in any case, when USB Power 5 VDC (pin 23) is fed, 25 must be connected to 5V through a 10kOhm resistor, and 27 must be connected to the Ground (for example: pin 1) with a 10kOhm resistor.
iPod 5G can also be forced to charge by attaching the data + and the data - pins to the 5v via a 10k Ohm resistor ( BOTH PINS) and connecting pin 16 to the 5v (ground). (Confirmed working with iPod 5G 20GB). This provides 500mA of current for charging. For quicker charing, up to 1A, see below.
To charge an iPhone, 3G, 3GS, 4 / iPod Touch, 2nd gen, 3rd, 4th or Ipod Classic (6th Gen), usb data- (25) should be at 2.8v, usb data+(27) should be at 2.0v. This can be done with a few simple resistors: 33k to +5v (23) and 22k to gnd(16) to obtain 2v and 33k to +5v and 47k to gnd to obtain 2.8v. This is a notification to the iphone that it is connected to the external charger and may drain amps from the usb.
To charge iPod Nano pins 25 and 27 should be tied together and then connected to a 10K ohm resistor, and the other side of this resistors then needs to be connected to 5v power.
It's also possible to charge the iPod's or iPhone's battery to make use the of internal +3.3v output (18) terminal to connect the USB Data + (27) thru a 47k ohms resistor and the USB Data- (25) thru a 47k resistor to the USB Power source +5v (23).  This way the USB function is still useable for normal operations and makes it easier the fit in a plug. The resistors are not to critical 2x 150k's still work.
Added correction: iPod 2.1A charger advertises 2.8V on D+ and 2.0V on D-.  Tying either wire to 5V could damage the target - use resistors tied to 5.1V and ground to be safe.