Support ELM327 error messages

obd/commands.py

@@ -287,15 +287,17 @@
 
 __mode9__ = [
     #                      name                             description                    cmd  bytes       decoder           ECU        fast
-    # OBDCommand("PIDS_9A"                    , "Supported PIDs [01-20]"                  , b"0900", 4, pid,                   ECU.ENGINE,  True),
-    # OBDCommand("VIN_MESSAGE_COUNT"          , "VIN Message Count"                       , b"0901", 1, uas(0x01),             ECU.ENGINE,  True),
-    # OBDCommand("VIN"                        , "Get Vehicle Identification Number"       , b"0902", 20, raw_string,           ECU.ENGINE,  True),
+    OBDCommand("PIDS_9A"                    , "Supported PIDs [01-20]"                  , b"0900", 4, pid,                   ECU.ENGINE,  True),
+    OBDCommand("VIN_MESSAGE_COUNT"          , "VIN Message Count"                       , b"0901", 1, uas(0x01),             ECU.ENGINE,  True),
+    OBDCommand("VIN"                        , "Get Vehicle Identification Number"       , b"0902", 20, raw_string,           ECU.ENGINE,  True),
 ]
 
 __misc__ = [
     #                      name                             description                    cmd  bytes       decoder           ECU        fast
     OBDCommand("ELM_VERSION"                , "ELM327 version string"                   , b"ATI",  0, raw_string,            ECU.UNKNOWN, False),
     OBDCommand("ELM_VOLTAGE"                , "Voltage detected by OBD-II adapter"      , b"ATRV", 0, elm_voltage,           ECU.UNKNOWN, False),
+    OBDCommand("FAKE_COMMAND_1"             , "Non-existing command returning error"    , b"ATXYZ", 0, raw_string,           ECU.UNKNOWN, False),
+
 ]
 
 

obd/elm327.py

@@ -101,6 +101,24 @@ class ELM327:
     # going to be less picky about the time required to detect it.
     _TRY_BAUDS = [ 38400, 9600, 230400, 115200, 57600, 19200 ]
 
+    _ERROR_MESSAGES = [
+            [b"?",                    "?: ELM327 reports misundersting command received on the RS232 input."],
+            [b"ACT ALERT",            "ACT ALERT: ELM327 warns no RS232 activity. Might switch to low-power standby mode."],
+            [b"BUFFER FULL",          "BUFFER FULL: ELM327 reports that RS232 buffer is filling at a faster rate than transmission. Increase baud speed."],
+            [b"BUS BUSY",             "BUS BUSY: ELM327 reports too much activity on BUS. Check wiring."],
+            [b"BUS ERROR",            "BUS ERROR: ELM327 reports a BUS error. This might be normal when starting CAN listening."],
+            [b"CAN ERROR",            "CAN ERROR: ELM327 reports a CAN system ERROR. CAN has difficulty initializing, sending or receiving."],
+            [b"<DATA ERROR",          "<DATA ERROR: ELM327 reports an error in the line number following."],
+            [b"DATA ERROR",           "DATA ERROR: ELM327 reports an error response from vehicule, data lost."],
+            [b"FB ERROR",             "EFB ERROR: ELM327 reports a feedBack(FB) error affecting signal. Check cable."],
+            [b"LP ALERT",             "LP ALERT: ELM327 is about to switch to the Low Power (standby) mode within 2 seconds."],
+            [b"LV RESET",             "LV RESET: ELM327 performed a low-voltage reset."],
+            [b"NO DATA",              "NO DATA: ELM327 returns no data, either because answer is empty or not understood or not supported."],
+            [b"<RX ERROR",            "<RX ERROR: ELM327 reports an error in the received CAN data. Check connection parameters."],
+            [b"STOPPED",              "STOPPED: ELM327 reports that OBD operation was interrupted by a received RS232 character, or by a low level on the RTS pin."],
+            [b"UNABLE TO CONNECT",    "UNABLE TO CONNECT: ELM327 tried all available protocols, and could not detect a compatible one."],
+            [b"ERR",                  "ERR: ELM327 reports an error number following."]
+            ]
 
 
     def __init__(self, portname, baudrate, protocol):
@@ -117,7 +135,6 @@ def __init__(self, portname, baudrate, protocol):
         self.__port     = None
         self.__protocol = UnknownProtocol([])
 
-
         # ------------- open port -------------
         try:
             self.__port = serial.Serial(portname, \
@@ -258,7 +275,7 @@ def auto_protocol(self):
     def set_baudrate(self, baud):
         if baud is None:
             # when connecting to pseudo terminal, don't bother with auto baud
-            if self.port_name().startswith("/dev/pts"):
+            if self.get_port_name().startswith("/dev/pts"):
                 logger.debug("Detected pseudo terminal, skipping baudrate setup")
                 return True
             else:
@@ -330,29 +347,36 @@ def __error(self, msg):
         logger.error(str(msg))
 
 
-    def port_name(self):
+    def get_port_name(self):
         if self.__port is not None:
             return self.__port.portstr
         else:
             return ""
 
 
-    def status(self):
-        return self.__status
-
-
-    def ecus(self):
-        return self.__protocol.ecu_map.values()
+    def get_port_baudrate(self):
+        if self.__port is not None:
+            return self.__port.baudrate
+        else:
+            return ""
 
 
-    def protocol_name(self):
+    def get_protocol_name(self):
         return self.__protocol.ELM_NAME
 
 
-    def protocol_id(self):
+    def get_protocol_id(self):
         return self.__protocol.ELM_ID
 
 
+    def get_ecus(self):
+        return self.__protocol.ecu_map.values()
+
+
+    def status(self):
+        return self.__status
+
+
     def close(self):
         """
             Resets the device, and sets all
@@ -442,14 +466,20 @@ def __read(self):
 
             # if nothing was recieved
             if not data:
-                logger.warning("Failed to read port")
+                logger.warning("Failed to read port: empty data.")
                 break
 
             buffer.extend(data)
 
             # end on chevron (ELM prompt character)
             if self.ELM_PROMPT in buffer:
                 break
+
+        #Check errors received by ELM327 and write debug
+        for iError in self._ERROR_MESSAGES:
+            if iError[0] in buffer:
+                logger.debug(iError[1])
+                break   
 
         # log, and remove the "bytearray(   ...   )" part
         logger.debug("read: " + repr(buffer)[10:-1])

obd/obd.py

@@ -155,40 +155,46 @@ def status(self):
             return self.interface.status()
 
 
-    # not sure how useful this would be
-
-    # def ecus(self):
-    #     """ returns a list of ECUs in the vehicle """
-    #     if self.interface is None:
-    #         return []
-    #     else:
-    #         return self.interface.ecus()
+    def get_ecus(self):
+        """ returns a list of ECUs in the vehicle """
+        if self.interface is None:
+            return []
+        else:
+            return self.interface.get_ecus()
 
 
-    def protocol_name(self):
+    def get_protocol_name(self):
         """ returns the name of the protocol being used by the ELM327 """
         if self.interface is None:
             return ""
         else:
-            return self.interface.protocol_name()
+            return self.interface.get_protocol_name()
 
 
-    def protocol_id(self):
+    def get_protocol_id(self):
         """ returns the ID of the protocol being used by the ELM327 """
         if self.interface is None:
             return ""
         else:
-            return self.interface.protocol_id()
+            return self.interface.get_protocol_id()
 
 
-    def port_name(self):
+    def get_port_name(self):
         """ Returns the name of the currently connected port """
         if self.interface is not None:
-            return self.interface.port_name()
+            return self.interface.get_port_name()
         else:
             return ""
 
 
+    def get_port_baudrate(self):
+        """ Returns the speed of the currently connected port """
+        if self.interface is not None:
+            return str(self.interface.get_port_baudrate())
+        else:
+            return ""
+
+
     def is_connected(self):
         """
             Returns a boolean for whether a connection with the car was made.
@@ -207,13 +213,46 @@ def print_commands(self):
         for c in self.supported_commands:
             print(str(c))
 
-
+    def print_discovered(self):
+        """
+            Utility function meant to print all information discovered:
+            protocol, port name, port baudrate and all supported commands.
+        """
+        if self.interface is not None:
+            print ("The following settings were used to connect to the ECU:")
+            print ("Protocole: " + self.get_protocol_name())
+            print ("Port name: " + self.get_port_name())
+            print ("Port rate: " + self.get_port_baudrate())
+            print ("The following OBD commands are supported:")
+
+            _mylist=[]
+            for c in self.supported_commands:
+                _mylist.append(str(c))
+            _mylist.sort()
+            for i in _mylist:
+                print (i)
+
+        else:
+            print ("Impossible to print discovered information: no connection to the ECU.")
+
     def supports(self, cmd):
         """
             Returns a boolean for whether the given command
             is supported by the car
         """
         return cmd in self.supported_commands
+
+
+    def get_supported_commands(self):
+        """
+            Returns a list of commands
+            supported by the car
+        """
+
+        if self.interface is not None:
+            return self.supported_commands
+        else:
+            return []
 
 
     def test_cmd(self, cmd, warn=True):
@@ -228,7 +267,7 @@ def test_cmd(self, cmd, warn=True):
             return False
 
         # mode 06 is only implemented for the CAN protocols
-        if cmd.mode == 6 and self.interface.protocol_id() not in ["6", "7", "8", "9"]:
+        if cmd.mode == 6 and self.interface.get_protocol_id() not in ["6", "7", "8", "9"]:
             if warn:
                 logger.warning("Mode 06 commands are only supported over CAN protocols")
             return False

tests/test_OBD.py

@@ -23,7 +23,7 @@ def __init__(self, portname, UNUSED_baudrate=None, UNUSED_protocol=None):
         self._status = OBDStatus.CAR_CONNECTED
         self._last_command = None
 
-    def port_name(self):
+    def get_port_name(self):
         return self._portname
 
     def status(self):
@@ -32,10 +32,10 @@ def status(self):
     def ecus(self):
         return [ ECU.ENGINE, ECU.UNKNOWN ]
 
-    def protocol_name(self):
+    def get_protocol_name(self):
         return "ISO 15765-4 (CAN 11/500)"
 
-    def protocol_id(self):
+    def get_protocol_id(self):
         return "6"
 
     def close(self):
@@ -122,30 +122,30 @@ def test_port_name():
     """
     o = obd.OBD("/dev/null")
     o.interface = FakeELM("/dev/null")
-    assert o.port_name() == o.interface._portname
+    assert o.get_port_name() == o.interface.get_port_name()
 
     o.interface = FakeELM("A different port name")
-    assert o.port_name() == o.interface._portname
+    assert o.get_port_name() == o.interface.get_port_name()
 
 
 def test_protocol_name():
     o = obd.OBD("/dev/null")
 
     o.interface = None
-    assert o.protocol_name() == ""
+    assert o.get_protocol_name() == ""
 
     o.interface = FakeELM("/dev/null")
-    assert o.protocol_name() == o.interface.protocol_name()
+    assert o.get_protocol_name() == o.interface.get_protocol_name()
 
 
 def test_protocol_id():
     o = obd.OBD("/dev/null")
 
     o.interface = None
-    assert o.protocol_id() == ""
+    assert o.get_protocol_id() == ""
 
     o.interface = FakeELM("/dev/null")
-    assert o.protocol_id() == o.interface.protocol_id()
+    assert o.get_protocol_id() == o.interface.get_protocol_id()