def test_parse_invalid_header(self):
parser = MessageParser()
crc_calc = Crc8Calculator(0x97)
msg = bytearray(10)
msg[0] = 0xFE
msg[1] = 0x03
msg[2] = 0x00
msg[3:9] = 'Hello '.encode()
msg[9] = crc_calc.compute_crc(msg[0:9])
with self.assertRaises(AssertionError) as cm:
parser.parse_incoming_message(msg)
self.assertEqual('Invalid message header', str(cm.exception))
def test_parse_string_message(self):
parser = MessageParser()
crc_calc = Crc8Calculator(0x97)
msg = bytearray(10)
msg[0] = 0xFF
msg[1] = 0x03
msg[2] = 0x00
msg[3:9] = 'Hello '.encode()
msg[9] = crc_calc.compute_crc(msg[0:9])
expected_parsed_message = dict()
expected_parsed_message['type'] = 'string'
expected_parsed_message['id'] = 0x00
expected_parsed_message['data'] = 'Hello '
self.assertEqual(expected_parsed_message, parser.parse_incoming_message(msg))
def test_pack_command(self):
parser = MessageParser()
crc_calc = Crc8Calculator(0x97)
ADDRESS = 0x01
SUB_ADDRESS = 0x02
DATA = 10
expected_msg = bytearray(10)
expected_msg[0] = 0xFF
expected_msg[1] = 0x00
expected_msg[2] = 0x00
expected_msg[3] = ADDRESS
expected_msg[4] = SUB_ADDRESS
expected_msg[5:9] = DATA.to_bytes(4, byteorder='little')
expected_msg[9] = crc_calc.compute_crc(expected_msg[0:9])
self.assertEqual(expected_msg, parser.pack_command(ADDRESS, SUB_ADDRESS, DATA))
def __init__(self):
"""
"""
CRC_POLYNOMIAL = 0x97
self.app_logger = getLogger('application.usart_communication')
self.app_logger.info('Creating serial communicator')
self.__parser = MessageParser()
self.__arduino_logger = ArduinoLogger()
self.__serial_port = Serial()
self.__crc_calculator = Crc8Calculator(CRC_POLYNOMIAL)
self.__receiver_thread = Thread(target=self.__read_incoming_message)
self.__is_reading = False
self.__request_queue = Queue()
self.__command_queue = Queue()
self.__request_counter = 0
self.__command_counter = 0
self.__input_message_queue = Queue()
class ArduinoSerialCommunicator(IArduinoCommunicator):
"""
"""
def __init__(self):
"""
"""
CRC_POLYNOMIAL = 0x97
self.app_logger = getLogger('application.usart_communication')
self.app_logger.info('Creating serial communicator')
self.__parser = MessageParser()
self.__arduino_logger = ArduinoLogger()
self.__serial_port = Serial()
self.__crc_calculator = Crc8Calculator(CRC_POLYNOMIAL)
self.__receiver_thread = Thread(target=self.__read_incoming_message)
self.__is_reading = False
self.__request_queue = Queue()
self.__command_queue = Queue()
self.__request_counter = 0
self.__command_counter = 0
self.__input_message_queue = Queue()
def request_object_data(self, address, sub_address):
content = self.__parser.pack_request(self.__command_counter, address, sub_address)
self.app_logger.debug('Writing request to arduino: %s', hexlify(content))
self.__serial_port.write(content)
msg = self.__get_incoming_message()
if msg['id'] == self.__command_counter:
self.app_logger.debug('Request replied successfully')
print('Arduino replied with: %s' % msg['data'])
self.__request_counter += 1
self.__request_counter %= 256
def open(self, port_name):
self.__serial_port.port = port_name
self.__serial_port.baudrate = 57600
self.__serial_port.open()
self.__start_reading()
def close(self):
self.__stop_reading()
self.__serial_port.close()
def write_to_object(self, address, sub_address, data):
content = self.__parser.pack_command(self.__command_counter, address, sub_address, data)
self.app_logger.debug('Writing command to arduino')
self.app_logger.debug(content)
self.__serial_port.write(content)
msg = self.__get_incoming_message()
if msg['id'] == self.__command_counter:
if msg['data'] == 1:
self.app_logger.debug('Command applied successfully')
self.__command_counter += 1
self.__command_counter %= 256
def __start_reading(self):
self.__is_reading = True
self.__receiver_thread.setDaemon(True)
self.__receiver_thread.start()
def __stop_reading(self):
self.__is_reading = False
self.__receiver_thread.join()
def __read_incoming_message(self):
incoming_message = bytearray()
msg_size = 0
try:
while self.__is_reading:
data = ord(self.__serial_port.read(1))
# First byte condition
if data == 0xFF and len(incoming_message) == 0:
incoming_message.append(data)
# Complete header (0xFF + msgType) Stop to determine size
elif len(incoming_message) == 1:
incoming_message.append(data)
msg_size = self.__parser.get_message_size(incoming_message)
elif 1 < len(incoming_message) < msg_size:
incoming_message.append(data)
if len(incoming_message) == msg_size:
self.__process_message(incoming_message)
incoming_message = bytearray()
msg_size = 0
except SerialException as e:
self.app_logger.fatal('Error reading serial port:')
self.app_logger.fatal(e.strerror)
def __process_message(self, message):
self.app_logger.debug('Processing incoming message.')
assert(type(message) is bytearray)
parsed_msg = dict(type='unknown')
try:
parsed_msg = self.__parser.parse_incoming_message(message)
except AssertionError as ae:
self.app_logger.error('Invalid incoming message with error ' + ae.args[0])
self.app_logger.error('Data: %s' % hexlify(message))
self.__serial_port.flush()
if parsed_msg['type'] == 'string':
self.__arduino_logger.process_log_message(parsed_msg)
elif parsed_msg['type'] == 'error':
self.app_logger.warning('Arduino replied with error message')
self.app_logger.warning('Data: %s' % hexlify(message))
else:
self.app_logger.debug('Message put in queue')
self.app_logger.debug('Type: %s' % parsed_msg['type'])
self.__input_message_queue.put(parsed_msg)
def __get_incoming_message(self):
msg = self.__input_message_queue.get()
self.app_logger.debug('Message read from queue')
self.app_logger.debug('Type: %s' % msg['type'])
self.__input_message_queue.task_done()
return msg
