def test_class_with_known_answers(self):
for crcfun_name, v in self.known_answers:
for i, msg in enumerate(self.test_messages_for_known_answers):
crc1 = PredefinedCrc(crcfun_name)
crc1.update(msg)
self.assertEqual(
crc1.crcValue, v[i],
"Wrong answer for crc1 %s, input '%s'" %
(crcfun_name, msg))
crc2 = crc1.new()
# Check that crc1 maintains its same value, after .new() call.
self.assertEqual(
crc1.crcValue, v[i],
"Wrong state for crc1 %s, input '%s'" % (crcfun_name, msg))
# Check that the new class instance created by .new() contains the initialisation value.
# This depends on the first string in self.test_messages_for_known_answers being
# the empty string.
self.assertEqual(
crc2.crcValue, v[0],
"Wrong state for crc2 %s, input '%s'" % (crcfun_name, msg))
crc2.update(msg)
# Check that crc1 maintains its same value, after crc2 has called .update()
self.assertEqual(
crc1.crcValue, v[i],
"Wrong state for crc1 %s, input '%s'" % (crcfun_name, msg))
# Check that crc2 contains the right value after calling .update()
self.assertEqual(
crc2.crcValue, v[i],
"Wrong state for crc2 %s, input '%s'" % (crcfun_name, msg))
def test_class_predefined_table(self):
for table_entry in _predefined_crc_definitions:
# Check predefined class
crc1 = PredefinedCrc(table_entry['name'])
crc1.update("123456789")
self.assertEqual(crc1.crcValue, table_entry['check'],
"Wrong answer for CRC '%s'" % table_entry['name'])
def __init__(self, data):
"""
Create an LDP packet
Returns a new LDP packet
Args:
data (bytes) : packet contents
Throws ValueError if packet is malformed
"""
if len(data) < self.__header_len + self.__checksum_len:
raise ValueError('Malformed LDP packet: too short')
header = struct.unpack('>L', data[:self.__header_len])[0]
self.type = header >> 24
self.length = header & 0xffffff
if self.length > len(data):
raise ValueError('Malformed LDP packet: invalid length')
crc = PredefinedCrc('crc-32-mpeg')
crc.update(data[:self.length])
if crc.crcValue != 0:
raise ValueError('Malformed LDP packet: invalid checksum')
self.payload = data[self.__header_len:self.length -
self.__checksum_len]
def __init__(self, port):
if port:
self._com = Serial(port, baudrate=115200, timeout=1.0)
if self._com is None:
raise Exception("environment sensor is not found")
else:
raise Exception("no such environment sensor COM port")
self._crc16func = mkPredefinedCrcFun('crc-16')
self._crc16obj = PredefinedCrc('crc-16')
def test_class_with_known_answers(self):
for crcfun_name, v in self.known_answers:
for i, msg in enumerate(self.test_messages_for_known_answers):
crc1 = PredefinedCrc(crcfun_name)
crc1.update(msg)
self.assertEqual(crc1.crcValue, v[i], "Wrong answer for crc1 %s, input '%s'" % (crcfun_name,msg))
crc2 = crc1.new()
# Check that crc1 maintains its same value, after .new() call.
self.assertEqual(crc1.crcValue, v[i], "Wrong state for crc1 %s, input '%s'" % (crcfun_name,msg))
# Check that the new class instance created by .new() contains the initialisation value.
# This depends on the first string in self.test_messages_for_known_answers being
# the empty string.
self.assertEqual(crc2.crcValue, v[0], "Wrong state for crc2 %s, input '%s'" % (crcfun_name,msg))
crc2.update(msg)
# Check that crc1 maintains its same value, after crc2 has called .update()
self.assertEqual(crc1.crcValue, v[i], "Wrong state for crc1 %s, input '%s'" % (crcfun_name,msg))
# Check that crc2 contains the right value after calling .update()
self.assertEqual(crc2.crcValue, v[i], "Wrong state for crc2 %s, input '%s'" % (crcfun_name,msg))
def __bytes__(self):
data = self.gen_data()
crc = PredefinedCrc('crc-16-mcrf4xx')
crc.update(data)
digest = crc.digest()
return data + bytes([digest[1], digest[0]])
class EnvSensor:
def __init__(self, port):
if port:
self._com = Serial(port, baudrate=115200, timeout=1.0)
if self._com is None:
raise Exception("environment sensor is not found")
else:
raise Exception("no such environment sensor COM port")
self._crc16func = mkPredefinedCrcFun('crc-16')
self._crc16obj = PredefinedCrc('crc-16')
def read_datas(self):
datas = None
self._send_command_for_read(0x5012)
resp = self._recv_response()
if resp:
datas = EnvSensor._parse_latest_sensing_data(resp)
self._send_command_for_read(0x5013)
resp = self._recv_response()
if resp:
calc_datas = EnvSensor._parse_latest_calculation_data(resp)
if datas:
datas.update(calc_datas)
else:
datas = calc_datas
return datas
def _send_command_for_read(self, addr):
command = bytearray([0x52, 0x42, 0x05, 0x00, 0x01, (addr & 0xFF), (addr >> 8)])
crc = self._crc16func(command, crc=0xFFFF)
command.append(crc & 0xFF)
command.append(crc >> 8)
self._com.write(command)
def _recv_response(self):
resp_header = self._com.read(5)
if (resp_header[0] != 0x52) or (resp_header[1] != 0x42):
return None
resp_len = resp_header[2] + (resp_header[3] << 8)
if (resp_header[4] & 0x80):
ignore_bytes = self._com.read(resp_len - 1)
return None # error response
payload_len = resp_len - 2
resp_body = self._com.read(payload_len - 1)
self._crc16obj.crcValue = 0xFFFF
self._crc16obj.update(resp_header)
self._crc16obj.update(resp_body)
resp_crc = (self._com.read())[0] + ((self._com.read())[0] << 8)
if (resp_crc != self._crc16obj.crcValue):
print("unexpected CRC value on response: ", resp_crc)
return None
return resp_body
@staticmethod
def _parse_latest_sensing_data(resp):
datas = {}
# skip addr and sequence number
pos = 2 # skip addr
pos += 1 # sequence number
# read rest fields
datas["temperature"] = read16bit_value(resp, pos, 0.01)
pos += 2
datas["humidity"] = read16bit_value(resp, pos, 0.01)
pos += 2
datas["illuminance"] = read16bit_value(resp, pos, 1)
pos += 2
datas["air_pressure"] = read32bit_value(resp, pos, 0.001)
pos += 4
datas["sound_noise"] = read16bit_value(resp, pos, 0.01)
pos += 2
datas["e_tvoc"] = read16bit_value(resp, pos, 1)
pos += 2
datas["e_co2"] = read16bit_value(resp, pos, 1)
return datas
@staticmethod
def _parse_latest_calculation_data(resp):
datas = {}
# skip addr and sequence number
pos = 2
pos += 1
# read rest fields
datas["discomfort_index"] = read16bit_value(resp, pos, 0.01)
pos += 2
datas["heat_stroke_alarmness"] = read16bit_value(resp, pos, 0.01)
pos += 2
datas["vibr_info"] = resp[pos]
return datas
def test_class_predefined_table(self):
for table_entry in _predefined_crc_definitions:
# Check predefined class
crc1 = PredefinedCrc(table_entry['name'])
crc1.update("123456789")
self.assertEqual(crc1.crcValue, table_entry['check'], "Wrong answer for CRC '%s'" % table_entry['name'])
def crc(self):
crc = PredefinedCrc('crc-16-buypass')
crc.update(self.value[:-2])
return crc.crcValue
