Thanks for your input guys - far-seeker, are you saying that I can only have a proper question-based user interface if I create a separate application using another IDE? Yes karlok - ideally I want to use the Arduino IDE for the interface - but all I have seen of it so far is you put in a command and it gets sent to the arduino. I want the user to be asked questions before you type a command! (eg What position are you? or Would you like to switch the LED off?) So I can just do that with Serial.print and if statements?