what I2C means?

[RyanCahoon]

Originally Posted by AndrewN

It is a 4 wire connection from computers to devices

As was stated before, it only uses two wires, a data line and a clock signal line. Other signals are sometimes passed with it, such as ground and power, but those aren't officially part of the bus specification. Compare with something like SPI (previously mentioned) that has additional signals for chip select and a second data line so it can run in full duplex (a device can send and receive at the same time)

[AndrewN]

You are quite right in that I2C only requires 2 pins of the processor for the signaling and it can be made to work only over 2 wires if a bridge has been used and the device doesn't have the same power source as the processor. However, in practice the devices and the processor share a common Vdd wire for power and a ground wire - total 4 wires. If you cut the cord between the Wii remote and the Nunchuk there are 4 wires - that's all I was attempting to convey.

The specification from Phillips details all the various electrical requirements for those interested, wikipedia does not.

http://www.nxp.com/acrobat_download/...8/39340011.pdf