Hi, from checking the program with some serial comms to the PC, to see where it is, when it doesn't work it doesn't even enter that part of the code (no serial comms between the reader and arduino). I don't understand what you mean, I need to read all bytes to check the serial number from the sensor to make sure it's mine.
Also I'm using serial1 because the pro-micro is a leonardo derivative and serial is for PC and serial1 is hardware serial. At least from my understanding.