Too bad, but I understand....
But just for my understanding. In general, it shouldn't be any problem to receive serial data at a baud rate of 115200 while simultaneously every 30 ms a Timer-ISR is running which only sets one flag, right? Do I actually need a cli() ... sei() when I reset my volatile flag? Or is it impossible that the ISR coincidentally corrupts the flag when it is triggered at this specific moment?
Thank you very much in advance