is it safe to just unplug from the computer? is there a special sequence to do it correctly?
Thanks
Yes. No.
If you leave the serial monitor open with nothing plugged in then it does seem to use a bit of battery power on my laptop, but that might just be my system.
Failing to close the serial monitor often causes the serial monitor process to consume 100% CPU (hence the
battery consumption), and on some OS's it even hangs the USB system for a short while too!
The Arduino isn't going to care at all. (unless you are using EEPROM writes in your sketch, then you might have to worry a little)