Problem with QSerialPort

[anda_skoa]

My problem is the following, I have two slot functions connected to a QPushButton

You are aware that both slots will be called for each click, right?

Why is the message not sent to the arduino when I send it through the slot functions A and B?

Maybe closing the port aborts sending any bytes that have not been sent yet.
I.e. if write() is not synchronous the stop message might still be on the PC side and close might simply discard it.

Cheers,
_