Im getting frustrated with my electronic knowledge, because I want to do this simple thing: Olimex 328/ATMega328 reads data from UART (Olimex MOD-PULSE or whatever) and forwards it to the USB Port (my computer). I dont understand how I can do this, I wrote following programm void setup() // run once, when the sketch starts { Serial.begin(9600); Serial1.begin(9600); } void loop() // run over and over again { Serial.println(Serial1.read()); // prints hello with ending line break } But it doesnt work, since Serial1 is not existing.. Could you give me a hint? I dont find anything understandable (for me) in the internet... Thanks!