demo.dtu/dtu_protocol_data.py
elian.wang d5c4007e32 1.删除offline_storage.py文件
2.将所有py文件中的'改为"
3.将透传模式从modbus中分成单独文件through_mode
4.将uart中从串口和云端接收数据处理的函数重新命名
5.将command.py文件改为command_mode.py文件、将modbus.py文件改为modbus_mode.py文件
2022-05-06 19:47:27 +08:00

62 lines
2.1 KiB
Python

from usr.modules.common import Singleton
class DtuProtocolData(Singleton):
def __init__(self):
self.crc_table = []
self._create_table()
def _create_table(self):
poly = 0xEDB88320
a = []
for byte in range(256):
crc = 0
for bit in range(8):
if (byte ^ crc) & 1:
crc = (crc >> 1) ^ poly
else:
crc >>= 1
byte >>= 1
a.append(crc)
self.crc_table = a
def crc32(self, crc_string):
value = 0xffffffff
for ch in crc_string:
value = self.crc_table[(ord(ch) ^ value) & 0xff] ^ (value >> 8)
crc_value = str((-1 - value) & 0xffffffff)
return crc_value
def package_datas(self, msg_data, topic_id=False, request_msg=False):
print(msg_data)
if len(msg_data) == 0:
if request_msg is not False:
ret_bytes = "%s,%s,%d".encode("utf-8") % (str(request_msg), str(topic_id), len(msg_data))
else:
ret_bytes = "%s,%d".encode("utf-8") % (str(topic_id), len(msg_data))
else:
crc32_val = self.crc32(str(msg_data))
msg_length = len(str(msg_data))
if request_msg is not False:
ret_bytes = "%s,%s,%s,%s,%s".encode("utf-8") % (str(request_msg), str(topic_id), str(msg_length), str(crc32_val), str(msg_data))
else:
ret_bytes = "%s,%s,%s,%s".encode("utf-8") % (str(topic_id), str(msg_length), str(crc32_val), str(msg_data))
return ret_bytes
def validate_length(self, data_len, msg_data, str_msg):
if len(msg_data) < data_len:
self.concat_buffer = str_msg
self.wait_length = data_len - len(msg_data)
print("wait length")
print(self.wait_length)
return False
elif len(msg_data) > data_len:
self.concat_buffer = ""
self.wait_length = 0
return False
else:
self.concat_buffer = ""
self.wait_length = 0
return True