Suddenly decided that I needed a USB OTG cable. Rather than wait for one in the post, i decided to make one from spare cables found in my box of bits.
Initially I thought that it would be a simple case of just cutting the cables and reconnecting a USB connector from a phone lead to a female USB socket. Unfortunately that is not the case.
The USB cable has four wires, but the micro USB plug has five contacts. The unused contact needs to connected to ground to make the OTG cable. The plug on the cable I used does not have a connection for the extra pin, so I needed to rip it apart and blob a lump of solder on two pins. The body of the plug has a wall between each pin, so I rammed a small screwdriver in there to allow the soldered pins to fit.
I then reassembled the plug, and continued with the connecting the wires together. This was an easy case of , red to red, black to black, green to green and white to white. A piece of heat shrink covers the mess.
Now to use it. It allows me to plug a keyboard into my Nexus tablet. If I plug a mouse in, a pointer pops up. All of a sudden using the tablet feels like using a real computer. I am typing this with a keyboard on my lap down the garden with my tablet.
The real motivation for the cable was to allow me to use my phone to adjust the settings on my MultiWii based control board of my Quadcopter. For that, it seems even better than MultiWiiConf, and certainly a lot more convenient when out flying.