I am trying to open a serial communication sending data from Arduino mega to Uno32 port1 pin 0,1. No data is transferred. I have disconnect the USB from the board and support it from power supply. I can not se the LED on Uno32 blinking. If I use port2 pin 39,40 on Uno32 the LED is blinking in the same time as the LED on mega is blinking and data is transfered. Edit: Forget this question. It was bad connection.