We tried using the wire examples: Arduino1 as the master writer and Arduino2 as the slave receiver.
as the exampled worked we got the hello looping on serial monitor of Arduino2 so we try to modify the program like this:
Wire.begin(); // join i2c bus (address optional for master)
Wire.beginTransmission(4); // transmit to device #4
Wire.write(rx_byte); // sends five bytes
Wire.endTransmission(); // stop transmitting
I don't know to much of the libraries function so I just fooled around with it.