ΠΑΩ ΝΑ ΤΡΕΞΩ ΤΟ ΠΡΩΤΟ ΠΑΡΑΔΕΙΓΜΑ ΣΕ ΕΝΑ MEGA 2560 ΚΑΙ ΜΟΥ ΒΓΑΖΕΙ ΑΥΤΟ ΤΟ ΜΗΝΥΜΑ...
Arduino: 1.6.4 (Windows 7), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"
Sketch uses 1,518 bytes (0%) of program storage space. Maximum is 253,952 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 8,183 bytes for local variables. Maximum is 8,192 bytes.
avrdude: ser_open(): can't open device "\.\COM3": The system cannot find the file specified.
avrdude: ser_drain(): read error: The handle is invalid.
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.