Of course I can't understand the write() values. I changed the code up in order to make sure the potentiometer is working as intended, and then changed it back so that it can communicate with Processing.
I am supposed to change the amount of bytes in the buffer with the Serial.write() right? Because I still can't change that.
EDIT
FINALLY! I solved my issues. I simply increased the delay in the Arduino sketch, so instead of a 1 ms delay after each write(), I changed it to 100 ms!
However, I'm still interested about how this communication really works. Where can I read about this?
THANKS PaulS!