test_uart_comm.py~

#!/usr/bin/python

import sys

print(sys.version_info)
import serial

def create_msg(main_type, subtype, msg_id, data):
    msg = bytes()
    msg += b'\xBE'
    msg += main_type.to_bytes(1, 'little')
    msg += subtype.to_bytes(1, 'little')
    msg += msg_id.to_bytes(2, 'little')
    msg += len(data).to_bytes(2, 'little')
    msg += data
    
    checksum = 0
    for b in msg:
        checksum ^= b
    msg += checksum.to_bytes(1, 'little')
    return msg

def create_test_packet(size=8):
    data = bytes((i % 256 for i in range(size)))
    return create_msg(0, 2, 0, data)

def read_packet(ser):
    header = ser.read(7)
    length = int.from_bytes(header[5:7], byteorder='little')
    data = ser.read(length)
    checksum = ser.read()
    return data

def query_received(ser):
    # Send request
    query_msg = create_msg(0, 3, 0, b'')
    ser.write(query_msg)
    ser.flush()
    
    resp = read_packet(ser)
    received_str = resp[:-1].decode()

    return tuple(map(int, received_str.split(',')))

if __name__ == '__main__':
    with serial.Serial('/dev/ttyUSB0', 921600, timeout=5) as ser:
        ser.write(create_test_packet(500))
        ser.flush()
        print(query_received(ser))