Arduino recieving binary I was wondering if Arduino digital pin can receive binary data. For example, I might want one Arduino to send another Arduino a binary code. If the code is 01 it would turn a red led on, if it was 11 it would turn green on, etc. I would like to do this so that I don't have to use a lot of digital pins. Is this possible with Arduino or not?
Pretty much anything is possible.

There is a method known as bit banging which toggles a generic IO pin to create a protocol, and read changes on another generic IO pin to read in the data of a protocol.

The trick is in creating a protocol.

Fortunately that has all been done for you - the SoftwareSerial library. It will create a bit banged version of the RS232 serial protocol using any combination of IO pins to transfer data between devices.