主要是通过python-can模块与pcan等支持的硬件通讯，uds协议层使用udsoncan模块和can-isotp模块实现uds诊断。
1、模块安装及相关文档
python-can模块
pip install python-can
相关文档链接：Installation - python-can 4.1.0 documentation
udsoncan模块
pip install udsoncan
相关文档链接：Python implementation of UDS standard (ISO-14229) — udsoncan 0 documentation
can-isotp模块
pip install can-isotp
相关文档链接：Python support for IsoTP Transport protocol (ISO-15765) — isotp 0 documentation
2、相关示例
下面示例展示了如何将PythonIsoTpConnection与Vector接口一起使用。
from can.interfaces.vector import VectorBus
from udsoncan.connections import PythonIsoTpConnection
from udsoncan.client import Client
import isotp
# Refer to isotp documentation for full details about parameters
isotp_params = {
'stmin' : 32, # Will request the sender to wait 32ms between consecutive frame. 0-127ms or 100-900ns with values from 0xF1-0xF9
'blocksize' : 8, # Request the sender to send 8 consecutives frames before sending a new flow control message
'wftmax' : 0, # Number of wait frame allowed before triggering an error
'tx_data_length' : 8, # Link layer (CAN layer) works with 8 byte payload (CAN 2.0)
'tx_data_min_length' : None, # Minimum length of CAN messages. When different from None, messages are padded to meet this length. Works with CAN 2.0 and CAN FD.
'tx_padding' : 0, # Will pad all transmitted CAN messages with byte 0x00.
'rx_flowcontrol_timeout' : 1000, # Triggers a timeout if a flow control is awaited for more than 1000 milliseconds
'rx_consecutive_frame_timeout' : 1000, # Triggers a timeout if a consecutive frame is awaited for more than 1000 milliseconds
'squash_stmin_requirement' : False, # When sending, respect the stmin requirement of the receiver. If set to True, go as fast as possible.
'max_frame_size' : 4095 # Limit the size of receive frame.
}
bus = VectorBus(channel=0, bitrate=500000) # Link Layer (CAN protocol)
tp_addr = isotp.Address(isotp.AddressingMode.Normal_11bits, txid=0x123, rxid=0x456) # Network layer addressing scheme
stack = isotp.CanStack(bus=bus, address=tp_addr, params=isotp_params) # Network/Transport layer (IsoTP protocol)
stack.set_sleep_timing(0, 0) # Speed First (do not sleep)
conn = PythonIsoTpConnection(stack) # interface between Application and Transport layer
with Client(conn, request_timeout=1) as client: # Application layer (UDS protocol)
client.change_session(1)
# ...其他uds服务相关使用示例：
import udsoncan
from udsoncan.connections import IsoTPSocketConnection
from udsoncan.client import Client
from udsoncan.exceptions import *
from udsoncan.services import *
udsoncan.setup_logging()
conn = IsoTPSocketConnection('can0', rxid=0x123, txid=0x456)
with Client(conn, request_timeout=2, config=MyCar.config) as client:
try:
client.change_session(DiagnosticSessionControl.Session.extendedDiagnosticSession) # integer with value of 3
client.unlock_security_access(MyCar.debug_level) # Fictive security level. Integer coming from fictive lib, let's say its value is 5
client.write_data_by_identifier(udsoncan.DataIdentifier.VIN, 'ABC123456789') # Standard ID for VIN is 0xF190. Codec is set in the client configuration
print('Vehicle Identification Number successfully changed.')
client.ecu_reset(ECUReset.ResetType.hardReset) # HardReset = 0x01
except NegativeResponseException as e:
print('Server refused our request for service %s with code "%s" (0x%02x)' % (e.response.service.get_name(), e.response.code_name, e.response.code))
except InvalidResponseException, UnexpectedResponseException as e:
print('Server sent an invalid payload : %s' % e.response.original_payload)安全算法示例，需要实现myalgo函数，并且uds的configs中的security_algo配置为myalgo，同时配置security_algo_params。文章来源：https://www.toymoban.com/news/detail-491330.html
def myalgo(level, seed, params):
"""
Builds the security key to unlock a security level. Returns the seed xor'ed with pre-shared key.
"""
output_key = bytearray(seed)
xorkey = bytearray(params['xorkey'])
for i in range(len(seed)):
output_key[i] = seed[i] ^ xorkey[i%len(xorkey)]
return bytes(output_key)
client.config['security_algo'] = myalgo
client.config['security_algo_params'] = dict(xorkey=b'\x12\x34\x56\x78')使用DID配置配置客户端，并使用ReadDataByIdentifier请求服务器文章来源地址https://www.toymoban.com/news/detail-491330.html
import udsoncan
from udsoncan.connections import IsoTPSocketConnection
from udsoncan.client import Client
import udsoncan.configs
import struct
class MyCustomCodecThatShiftBy4(udsoncan.DidCodec):
def encode(self, val):
val = (val << 4) & 0xFFFFFFFF # Do some stuff
return struct.pack('<L', val) # Little endian, 32 bit value
def decode(self, payload):
val = struct.unpack('<L', payload)[0] # decode the 32 bits value
return val >> 4 # Do some stuff (reversed)
def __len__(self):
return 4 # encoded payload is 4 byte long.
config = dict(udsoncan.configs.default_client_config)
config['data_identifiers'] = {
0x1234 : MyCustomCodecThatShiftBy4, # Uses own custom defined codec. Giving the class is ok
0x1235 : MyCustomCodecThatShiftBy4(), # Same as 0x1234, giving an instance is good also
0xF190 : udsoncan.AsciiCodec(15) # Codec that read ASCII string. We must tell the length of the string
}
# IsoTPSocketconnection only works with SocketCAN under Linux. Use another connection if needed.
conn = IsoTPSocketConnection('vcan0', rxid=0x123, txid=0x456)
with Client(conn, request_timeout=2, config=config) as client:
response = client.read_data_by_identifier([0xF190])
print(response.service_data.values[0xF190]) # This is a dict of DID:Value
# Or, if a single DID is expected, a shortcut to read the value of the first DID
vin = client.read_data_by_identifier_first(0xF190)
print(vin) # 'ABCDE0123456789' (15 chars)到了这里，关于使用python执行uds诊断的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！
