USB cables

[noel]

How can I make a female to female type A USB cable? I have two cables that I cut in half. I want to splice the cables together to have female USB connectors on both ends of the cable so I can join to USB male cables together. The purpose for this to connect my computer to my printer. Do I slice red to red, black to black, white to white and green to green OR red to black, black to red, white to green and green to white?

 

[garublador]

The short answer is to connect all the same color wires together assuming the same color wires go to the same pins on each cable. It's worth beeping though to be sure that both cables are made the same way, though.

The longer answer is that red is normally +5V and black is ground so you don't want to swap those around. The green and white are data+ and data- (or vice versa, I'm too lazy to look it up) so it's a differential pair, which is a fancy way to use two wires to make one logical connection that's much more impervious to noise. So it's not like a RS232 connection where one is transmit and the other is receive and you have to swap them at one side. Data- is just the logical inverse of data+, so swapping them will make it not work.

However, I'm a bit confused about what this cable will do. USB cables have a host side and a device side. The host is a type 'A' connector and the device is a type 'B' or 'C' connector. If you make a cable with two 'A' type female connectors that means you're connecting two host side connectors together which means you'll have a device on either side of the connection. Wouldn't you want a female A to male A to make an extension for a single cable or a female B to female A to make a bridge/extension between two cables?

 

[Bluejets]

Normally printers have a B type usb and the pc an A type.

 

[noel]

Thanks to everyone that posted an answer.

On the front of my Samsung printer has a "direct USB" port which is a type A male and the PC has a usb type A male connector. When I hook the two females together with the splice I just wanted to make sure that I won't fry the USB ports. According to the garublador reply I should not swap the wire connections and make a straight through connection. The RS232 analogy was the thought I had in mind when I posted this.

That being said I look at bluejets post. That post caused me to take a more thorough look at the back of the printer and I found the type B connector. Should have looked harder.

In my defence it is a black printer and the port is down in the far counter and under other ports and power cord and the room is on the dark side and the printer is in a hard to access place and the USB port on the front was easier to access.

 

[Bluejets]

I'd say the front A type is for a memory stick or whatever, NOT as an interface between the printer and a PC.

 

[garublador]

Finding some way to connect two type A ports is a bad idea. They'll both have 5V on the red wire so connecting them together would be bad. As Bluejets also pointed out, it won't work because two hosts can't communicate with one another.

In general it's not a good idea to make non-standard USB cables for reasons like this.