def reset(self, quick=True):
"""Reset the interface (scan tool)
quick -- peform a quick reset (if supported), otherwise perform
a slower, full reset
"""
if quick:
self.at_cmd("ATWS")
else:
# Since the baud rate might change after the ATZ, we just wait
# and clear the receive buffer.
self._write("ATZ\r")
time.sleep(ELM32X.ATZ_TIMEOUT)
self.port.clear_rx_buffer() # ignore any garbage due to wrong baud rate
debug("baud on reset = %s" % ELM32X.detect_baudrate(self.port))
return
def reset(self, quick=True):
"""Reset the interface (scan tool)
quick -- peform a quick reset (if supported), otherwise perform
a slower, full reset
"""
if quick:
self.at_cmd("ATWS")
else:
# Since the baud rate might change after the ATZ, we just wait
# and clear the receive buffer.
self._write("ATZ\r")
time.sleep(ELM32X.ATZ_TIMEOUT)
self.port.clear_rx_buffer() # ignore any garbage due to wrong baud rate
debug("baud on reset = %s" % ELM32X.detect_baudrate(self.port))
return
def _message_bytes_from_ascii(self, ascii_messages):
"""Convert each ASCII message into a list of raw bytes
and return the list of raw messages.
"""
raw_messages = []
debug(ascii_messages)
for message in ascii_messages:
message = message.replace(" ", "")
# pad 11-bit CAN headers out to 32 bits for consistency,
# since ELM already does this for 29-bit CAN headers
if len(message) & 1: message = "00000" + message
raw_message = []
for i in range(0, len(message), 2):
raw_message.append(int(message[i:i+2], 16))
raw_messages.append(raw_message)
debug(raw_messages)
return raw_messages
def _message_bytes_from_ascii(self, ascii_messages):
"""Convert each ASCII message into a list of raw bytes
and return the list of raw messages.
"""
raw_messages = []
debug(ascii_messages)
for message in ascii_messages:
message = message.replace(" ", "")
# pad 11-bit CAN headers out to 32 bits for consistency,
# since ELM already does this for 29-bit CAN headers
if len(message) & 1: message = "00000" + message
raw_message = []
for i in range(0, len(message), 2):
raw_message.append(int(message[i:i + 2], 16))
raw_messages.append(raw_message)
debug(raw_messages)
return raw_messages
def create(port, callback=None, baud=None):
"""Create an instance of the appropriate ELM32X subclass at the
given port
port -- the SerialPort subclass to which the interface is attached
callback -- the callback function used to provide status updates
(default None)
baud -- the baud rate to use, or None (default) to auto-detect
"""
# Use the appropriate baud rate, auto-detecting if requested
#print "Reached here"
if baud:
if port.get_baudrate() != baud:
untested("specifying the baud rate for obd.interface.elm.create()")
port.set_baudrate(baud)
else:
current_baud = ELM32X.detect_baudrate(port)
if not current_baud:
raise InterfaceError("Unable to connect to ELM; does it have power?")
#print "Reached here"
# Query the interface for its identity
identifier = ELM32X._at_cmd(port, "ATI")
if identifier.startswith("ATI\r"): identifier = identifier[4:]
debug(identifier)
chip_identifier, chip_version = identifier.split(" ")
#print identifier
# Check for extended command set
extended = ELM32X._at_cmd(port, "STI")
if extended.startswith("STI\r"): extended = extended[4:]
if extended != "?":
untested(extended)
chip_identifier, chip_version = extended.rsplit(" ", 1)
print extended
# Create an instance of the appropriate ELM32X subclass
try:
elm_class = _classes[chip_identifier]
except KeyError as e:
untested("unknown ELM response to ATI")
raise InterfaceError("Unknown response to ATI: %r" % identifier)
interface = elm_class(port, chip_identifier, callback=callback)
debug("%s detected on port %s at %d baud" %
(chip_identifier, interface.port.name, interface.port.get_baudrate()))
return interface
def create(port, callback=None, baud=None):
"""Create an instance of the appropriate ELM32X subclass at the
given port
port -- the SerialPort subclass to which the interface is attached
callback -- the callback function used to provide status updates
(default None)
baud -- the baud rate to use, or None (default) to auto-detect
"""
# Use the appropriate baud rate, auto-detecting if requested
if baud:
if port.get_baudrate() != baud:
untested("specifying the baud rate for obd.interface.elm.create()")
port.set_baudrate(baud)
else:
current_baud = ELM32X.detect_baudrate(port)
if not current_baud:
raise InterfaceError(
"Unable to connect to ELM; does it have power?")
# Query the interface for its identity
identifier = ELM32X._at_cmd(port, "ATI")
if identifier.startswith("ATI\r"): identifier = identifier[4:]
debug(identifier)
chip_identifier, chip_version = identifier.split(" ")
# Check for extended command set
extended = ELM32X._at_cmd(port, "STI")
if extended.startswith("STI\r"): extended = extended[4:]
if extended != "?":
untested(extended)
chip_identifier, chip_version = extended.rsplit(" ", 1)
# Create an instance of the appropriate ELM32X subclass
try:
elm_class = _classes[chip_identifier]
except KeyError as e:
untested("unknown ELM response to ATI")
raise InterfaceError("Unknown response to ATI: %r" % identifier)
interface = elm_class(port, chip_identifier, callback=callback)
debug(
"%s detected on port %s at %d baud" %
(chip_identifier, interface.port.name, interface.port.get_baudrate()))
return interface
def search_for_protocol(self):
"""Perform a robust search for the vehicle's protocol and
initiate a communication session with the vehicle's ECU,
returning the session protocol if successful.
This may take many seconds, as some protocols require a
delay after a failed test. To mitigate this, the specified
callback function will be called before trying each
supported protocol.
Raises an exception if unable to determine the protocol
and establish the connection.
"""
search_order = [
[obd.protocol.PWM(), 1.0],
[obd.protocol.VPW(), 0.0],
[obd.protocol.ISO9141_2(), 5.0],
[obd.protocol.ISO14230_4("5BAUD"), 5.0],
[obd.protocol.ISO14230_4("FAST"), 0.0],
[obd.protocol.ISO15765_4(id_length=11, baud=500000), 0.0],
[obd.protocol.ISO15765_4(id_length=29, baud=500000), 0.0],
[obd.protocol.ISO15765_4(id_length=11, baud=250000), 0.0],
[obd.protocol.ISO15765_4(id_length=29, baud=250000), 0.0],
]
supported_protocols = self.get_supported_protocols()
for protocol, delay in search_order:
if protocol not in supported_protocols:
continue
self._status_callback("Trying %s protocol..." % str(protocol))
self.set_protocol(protocol)
try:
self.connect_to_vehicle()
break
except obd.exception.ConnectionError as e:
debug("%s, delaying %f" % (str(e), delay))
time.sleep(delay)
else:
raise obd.exception.ProtocolError(
"unable to determine vehicle protocol")
return self.get_protocol()
def search_for_protocol(self):
"""Perform a robust search for the vehicle's protocol and
initiate a communication session with the vehicle's ECU,
returning the session protocol if successful.
This may take many seconds, as some protocols require a
delay after a failed test. To mitigate this, the specified
callback function will be called before trying each
supported protocol.
Raises an exception if unable to determine the protocol
and establish the connection.
"""
search_order = [
[obd.protocol.PWM(), 1.0],
[obd.protocol.VPW(), 0.0],
[obd.protocol.ISO9141_2(), 5.0],
[obd.protocol.ISO14230_4("5BAUD"), 5.0],
[obd.protocol.ISO14230_4("FAST"), 0.0],
[obd.protocol.ISO15765_4(id_length=11, baud=500000), 0.0],
[obd.protocol.ISO15765_4(id_length=29, baud=500000), 0.0],
[obd.protocol.ISO15765_4(id_length=11, baud=250000), 0.0],
[obd.protocol.ISO15765_4(id_length=29, baud=250000), 0.0],
]
supported_protocols = self.get_supported_protocols()
for protocol, delay in search_order:
if protocol not in supported_protocols:
continue
self._status_callback("Trying %s protocol..." % str(protocol))
self.set_protocol(protocol)
try:
self.connect_to_vehicle()
break
except obd.exception.ConnectionError as e:
debug("%s, delaying %f" % (str(e), delay))
time.sleep(delay)
else:
raise obd.exception.ProtocolError("unable to determine vehicle protocol")
return self.get_protocol()
def _process_obd_response(self, raw_frames):
"""Reassemble a list of raw frames into complete BusMessages,
assuming that the list of raw frames constitutes a complete
response.
"""
# When we get an OBD response from the interface, we assume that it's
# basically complete, having taken into account any relevant timeouts
for frame in raw_frames:
self._received_obd_frame(frame)
self._flush_frames()
result = []
try:
while True:
bus_message = self._complete_messages.get(False)
result.append(bus_message)
except Queue.Empty as e:
# The queue is exhausted, which just means we're done.
pass
debug([str(r) for r in result])
return result
def _process_obd_response(self, raw_frames):
"""Reassemble a list of raw frames into complete BusMessages,
assuming that the list of raw frames constitutes a complete
response.
"""
# When we get an OBD response from the interface, we assume that it's
# basically complete, having taken into account any relevant timeouts
for frame in raw_frames:
self._received_obd_frame(frame)
self._flush_frames()
result = []
try:
while True:
bus_message = self._complete_messages.get(False)
result.append(bus_message)
except Queue.Empty as e:
# The queue is exhausted, which just means we're done.
pass
debug([str(r) for r in result])
return result
def enumerate(callback=None):
"""Return a list of attached ELM32x OBD-II interfaces, each
of which is an instance of the appropriate ELM32X subclass.
callback -- the callback function to pass to the initializer
"""
interfaces = []
ports = obd.serialport.SerialPort.enumerate()
for port in ports:
try:
serialport = obd.serialport.SerialPort(port)
baud = ELM32X.detect_baudrate(serialport)
if baud:
interface = create(serialport, callback, baud)
interfaces.append(interface)
except serial.serialutil.SerialException as e:
raise InterfaceError(str(e))
except InterfaceError as e:
pass
except Exception as e:
debug(e)
return interfaces
def enumerate(callback=None):
"""Return a list of attached ELM32x OBD-II interfaces, each
of which is an instance of the appropriate ELM32X subclass.
callback -- the callback function to pass to the initializer
"""
interfaces = []
ports = obd.serialport.SerialPort.enumerate()
for port in ports:
try:
serialport = obd.serialport.SerialPort(port)
baud = ELM32X.detect_baudrate(serialport)
if baud:
interface = create(serialport, callback, baud)
interfaces.append(interface)
except serial.serialutil.SerialException as e:
raise InterfaceError(str(e))
except InterfaceError as e:
pass
except Exception as e:
debug(e)
return interfaces
def connect_to_vehicle(self):
"""Initiate a communication session with the vehicle's ECU
and return the session protocol.
This may take several seconds, particularly if automatic protocol
detection is being used. Where possible, the specified callback
function will be used to provide status updates.
Raises an exception if unable to establish the connection.
On an ELM32x interface, this sends an initial OBD command to
initiate the connection.
"""
self._current_status = ""
self.open()
if self.connected_to_vehicle:
raise CommandNotSupported("Already connected to vehicle")
self._protocol_response = None
self._status_callback("Connecting to vehicle...")
self._write("0100\r") # must be supported by all OBD-II vehicles
self._set_timeout(Interface.OBD_REQUEST_TIMEOUT)
# Read a complete line, allowing for incremental status updates
line = ""
status_line = False
while not line.endswith("\r"):
try:
line += self._read_until_string("")
except obd.exception.ReadTimeout as e:
raise InterfaceError(raw=line+e.response)
if not status_line:
if line.startswith("SEARCHING..."):
status_line = True
self._status_callback("Searching for protocol...")
elif line.startswith("BUS INIT: "):
status_line = True
self._status_callback("Initializing bus...")
if status_line and line == "SEARCHING...\r":
# The subsequent line will either be the error message
# or the OBD response, so eat this line and keep going.
status_line = False
line = ""
continue
# Handle connection failures
line = line[:-1] # strip \r
try:
if line.startswith("STOPPED"):
raise obd.exception.InterfaceBusy(line)
if line.endswith("UNABLE TO CONNECT") or line.endswith("ERROR"):
raise obd.exception.ConnectionError(raw=line)
if line.startswith("BUS INIT: ") and not line.endswith("OK"):
raise obd.exception.ConnectionError(raw=line)
if line == "NO DATA":
raise obd.exception.ConnectionError(raw=line) # probably not SAE J1850
except obd.exception.OBDException as e:
self._read_until_prompt() # swallow the rest of the response
raise e
line += "\r" # re-add \r
# Read the actual OBD response
if status_line: line = "" # swallow any status line
lines = self._read_response(previous_data=line)
debug("result: " + str(lines))
# Determine and verify the protocol established
self.connected_to_vehicle = True
self.vehicle_protocol = self.get_protocol()
# Process the response to make sure we got valid data
raw_frames = self._message_bytes_from_ascii(lines)
self._process_obd_response(raw_frames)
# Return the actual protocol established
return self.vehicle_protocol
def __init__(self, message="Timeout", response=None):
OBDException.__init__(self, message)
self.response = response
debug("response=%r" % response)
return
def __init__(self, message, raw=None):
if raw:
message = "%s (%s)" % (message, repr(raw))
Exception.__init__(self, message)
debug("%s: %s" % (type(self), message))
return
def connect_to_vehicle(self):
"""Initiate a communication session with the vehicle's ECU
and return the session protocol.
This may take several seconds, particularly if automatic protocol
detection is being used. Where possible, the specified callback
function will be used to provide status updates.
Raises an exception if unable to establish the connection.
On an ELM32x interface, this sends an initial OBD command to
initiate the connection.
"""
self._current_status = ""
self.open()
if self.connected_to_vehicle:
raise CommandNotSupported("Already connected to vehicle")
self._protocol_response = None
self._status_callback("Connecting to vehicle...")
self._write("0100\r") # must be supported by all OBD-II vehicles
self._set_timeout(Interface.OBD_REQUEST_TIMEOUT)
# Read a complete line, allowing for incremental status updates
line = ""
status_line = False
while not line.endswith("\r"):
try:
line += self._read_until_string("")
except obd.exception.ReadTimeout as e:
raise InterfaceError(raw=line + e.response)
if not status_line:
if line.startswith("SEARCHING..."):
status_line = True
self._status_callback("Searching for protocol...")
elif line.startswith("BUS INIT: "):
status_line = True
self._status_callback("Initializing bus...")
if status_line and line == "SEARCHING...\r":
# The subsequent line will either be the error message
# or the OBD response, so eat this line and keep going.
status_line = False
line = ""
continue
# Handle connection failures
line = line[:-1] # strip \r
try:
if line.startswith("STOPPED"):
raise obd.exception.InterfaceBusy(line)
if line.endswith("UNABLE TO CONNECT") or line.endswith("ERROR"):
raise obd.exception.ConnectionError(raw=line)
if line.startswith("BUS INIT: ") and not line.endswith("OK"):
raise obd.exception.ConnectionError(raw=line)
if line == "NO DATA":
raise obd.exception.ConnectionError(
raw=line) # probably not SAE J1850
except obd.exception.OBDException as e:
self._read_until_prompt() # swallow the rest of the response
raise e
line += "\r" # re-add \r
# Read the actual OBD response
if status_line: line = "" # swallow any status line
lines = self._read_response(previous_data=line)
debug("result: " + str(lines))
# Determine and verify the protocol established
self.connected_to_vehicle = True
self.vehicle_protocol = self.get_protocol()
# Process the response to make sure we got valid data
raw_frames = self._message_bytes_from_ascii(lines)
self._process_obd_response(raw_frames)
# Return the actual protocol established
return self.vehicle_protocol
