def putMessage(self, msgType, flags, data):
# data should be bytes
ph = struct.pack('<HHHL', msgType, flags, len(data), self.msgId)
crc = calcCrc16(ph)
crc = calcCrc16(data, crc)
header = struct.pack('<HHHHL', crc, msgType, flags, len(data), self.msgId)
msg = header + data
hexMsg = b'#' + binascii.hexlify(msg).upper() + b'!'
self.ser.write(hexMsg)
self.msgId += 2
print(hexMsg) # DEBUG
def putMessage(self, msgType, flags, data):
# data should be bytes
ph = struct.pack('<HHHL', msgType, flags, len(data), self.msgId)
crc = calcCrc16(ph)
crc = calcCrc16(data, crc)
header = struct.pack('<HHHHL', crc, msgType, flags, len(data),
self.msgId)
msg = header + data
hexMsg = b'#' + binascii.hexlify(msg).upper() + b'!'
self.ser.write(hexMsg)
self.msgId += 2
print(hexMsg) # DEBUG
def getMessage(self):
# Eat up data until the #
c = b'!'
while c and c != b'#': c = self.ser.read()
if not c: raise Exception('Timeout')
# Read the header
header = binascii.unhexlify(self.ser.read(24))
crc, msgType, flags, length, msgId = struct.unpack('<HHHHL', header)
if length > 512: raise Exception('Corrupt header')
# Read the message body
data = binascii.unhexlify(self.ser.read(length * 2))
# Check the crc
newCrc = calcCrc16(header[2:])
newCrc = calcCrc16(data, newCrc)
if newCrc != crc: raise Exception('CRC error')
# Handle the CONFIRMATION_NEEDED_FLAG by sending a confirmation
if flags & 0x01: self.putMessage(0, 0, struct.pack('<L', msgId))
return msgType, data
def getMessage(self):
# Eat up data until the #
c = b'!'
while c and c != b'#':
c = self.ser.read()
if not c: raise Exception('Timeout')
# Read the header
header = binascii.unhexlify(self.ser.read(24))
crc, msgType, flags, length, msgId = struct.unpack('<HHHHL', header)
if length > 512: raise Exception('Corrupt header')
# Read the message body
data = binascii.unhexlify(self.ser.read(length * 2))
# Check the crc
newCrc = calcCrc16(header[2:])
newCrc = calcCrc16(data, newCrc)
if newCrc != crc: raise Exception('CRC error')
# Handle the CONFIRMATION_NEEDED_FLAG by sending a confirmation
if flags & 0x01: self.putMessage(0, 0, struct.pack('<L', msgId))
return msgType, data
