Originally Posted by Jiffy82517
Although there are 5 pins in a miniusb plug, there are only 4 cables, the x-pin is not connected - so you need to get right into the plug. To connect to the ground pin I did as you suggested and stripped a bit of wire and then used my soldering iron to melt a section of the ground wire and soldered in there.
The other issue I've noticed when powering off the mains (via a 12v plug, into the supplied car adaptor taking it down to 5v) is that there is some sort of electrical noise. I'm not sure if it's from the switching adaptor in the wall wart, or just noise from the AC being converted to DC... but it is apparant in the final video. Maybe it can be reduced with a good sized capactor? I tried with a 1000uf one that I rescued from an old radio, but it had no effect... but then I wasn't positive the capacitor was in working order.
If the "pin-x" you are referring to is Pin 4 of the USB plug, if you read back through this thread, you'll find that pin should have the +5V normally found on pin 1 disconnected and reloctated to pin 4. Pin 5 next to it would be negative ground, and you should add some hot glue or some other insulating material between thos two pins to make sure they don't accidentally come in contact.