Transmitting IP packages using two spaghetti as transport medium
Actually this is rather RS232 over spaghetti. But using the SLIP protocol, some USB-to-RS232 adapters and two Linux machines, one can easily tunnel IP over RS232, thus effectively tunneling IP over the spaghetti.
The whole chain looks like this: SLIP(Linux) -> FTDI (USB<->RS232) -> ATMega328P -> Relais -> Spaghetti -> Optical Sensor -> ATMega328P -> FTDI (USB<->RS232) -> SLIP(Linux)
