Trial and error suggestion:
Get a multimeter and set it to a suitable voltage range (e.g. 20V DC). Let's start testing with the Black wire as we may strike lucky. Stick your Negative probe onto the black wire and start probing the other wires with the Positive.
If you get readings from all the other wires of the order of 2.98V and 3.38V like mine then you can assume that the Black wire in your cable is the same as that in the FTDI cable. Furthermore, you will have narrowed down the other wires into two groups - the Red and Green reading 3.38V and the Yellow, Orange, Brown reading 2.98V.
If you only get a reading from one of the wires then assume that this other wire corresponds to the FTDI Black wire. Now repeat the test treating it as the Black wire and take note of the voltages from the other wires.
Label your wires somehow so that you can identify which one should be called "Black" and which ones are "Red/Green" and "Yellow/Orange/Brown"
You're looking to get four wires from six in the correct order. There are 360 ways to arrange four wires from six BUT you now know one of those wires is Black so that leaves you looking for three wires from five which reduces the combinations down to 120.
You can further reduce this number as you know that the wires fall into three groups:
a] The known or designated Black wire
b] The 3.38V wires Red and Green
c] The 2.98V wires Yellow, Orange, Brown
Now you know that the wires can only go in certain positions in the connector block. Let's assign letters to those positions according to the FTDI cable colours:
K Black
G Green
O Orange
Y Yellow
Let's number your wires 1 thru 6:
(NB - substitute your colours for the ones listed here)
1 Black (Negative on you test)
2 Red (3.38V)
3 Green (3.38V)
4 Yellow (2.98V)
5 Orange (2.98V)
6 Brown (2.98V)
We have already identified which wire should be treated as Black (Wire #1) so it goes into the Black slot. That just leaves us with 3 slots to fill with 3 from 5 wires and the combinations are as follows:
Code: Select all
K G O Y
1 2 4 5
1 2 4 6
1 2 5 4
1 2 5 6
1 2 6 4
1 2 6 5
1 3 4 5
1 3 4 6
1 3 5 4
1 3 5 6
1 3 6 4
1 3 6 5
Now, if I've worked this out correctly that only leaves 12 combinations for you to try out, providing that you have identified the Black wire and decided which of the two groups (higher or lower voltage) that the other wires belong to.