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How to manually wire USB?

Posted: Mon Mar 05, 2012 9:49 pm
by Curran
Hi Folks,
I am making a bedside console for a quadriplegic. It is a steel arm that connects to the wall and pivots on 3 single DOF joints with an automatic locking mechanism.

The console needs power for a light, USB ports (phone, etc) and a motor that can all be powered with 5v (and under 100mA). We didn't want to bring 120V AC through the arm up to the console, so we are looking at transforming to 5V DC at the wall, running it up the length inside the arm with 16.2 wire then splitting it off to the motor/light/ports. As far as I can tell, bus-powered USB hubs will not work with just a 5v power supply as their circuitry is designed to use a computer to split the signals. Thats fine, we can manually split the power to USB females without a hub.

I was always assumed that most devices could be powered without the precense of the SDP/UTP signal pairs, and for the motor and light, this is obvious, but do devices such as blackberries and iphones have to have dummy signals on these wire pairs present to charge correctly? Can I not simplify the USB cord to just a n.2 wire (hotwire and ground) and still power an iphone?
Thanks for the help.
Curran

Re: How to manually wire USB?

Posted: Wed Mar 07, 2012 12:08 pm
by Daid
This has nothing to do with V-USB.

But, FYI, most devices charge with just the power connected. However, the iPhone is different. It will not work with just 5V connected, search online and you'll find a solution.