i2c or Uart?

I'm going to hack a system and do not know the protocol its using to communicate, whether its i2c or Uart ?
does this involve something like logic sniffer, or what?

does this involve something like logic sniffer, or what?

Without one you're going to have a hard time.

How do you know the options are only "I2C" and "UART"? There are a lot of proprietary serial protocols around also using two wires (and GND).

What's the device? Provide a link!. After that open it up and find out which chips it uses and look them up.

Mark