End of response to an AT command

Question

How to be sure what is end of an AT command send to GSM module?

I need some character or string that represent end of AT command for every case due to finding when

Answer 1

Here is what I used in Python. It works. There might be some other better solutions.

ser = serial.Serial(com, baudrate, timeout=5)
while True:
# a simple AT return result parser
    new_char = ser.read(1)
    byte_flow += new_char

    if len(byte_flow) >=4 and byte_flow[-4:] == b'\r\nOK':
        break
    elif len(byte_flow) >= 7 and byte_flow[-7:] == b'\r\nERROR':
        break
byte_flow += ser.read(2)  # the final '\r\n'

You can add more elif if there is any other patterns.