Problem with Baudrate - maybe also something different ;(

[ThomasMeister123]

Hello,

in my case there is a problem with the baudrate. The program connect to the OBD-adapter but then there comes an error:

`

[obd.obd] =================================================================== [obd.obd] ======================= python-OBD (v0.7.1) ======================= [obd.obd] Explicit port defined [obd.elm327] Initializing ELM327: PORT=/dev/rfcomm0 BAUD=auto PROTOCOL=auto [obd.elm327] Response from baud 38400: b'' [obd.elm327] Response from baud 9600: b'' [obd.elm327] Response from baud 230400: b'' [obd.elm327] Response from baud 115200: b'' [obd.elm327] Response from baud 57600: b'' [obd.elm327] Response from baud 19200: b'' [obd.elm327] Failed to choose baud [obd.elm327] closing port [obd.elm327] write: b'ATZ\r' [obd.elm327] Failed to set baudrate [obd.obd] Closing connection [obd.obd] Cannot load commands: No connection to car [obd.obd] =================================================================== [obd.obd] Query failed, no connection available None Traceback (most recent call last): File "/home/pi/Skripte/OBD.py", line 26, in print(response.value.to("mph")) # user-friendly unit conversions AttributeError: 'NoneType' object has no attribute 'to'

`

Whats wrong?

Python-Code: `

!/usr/bin/python3

import obd from obd import OBDStatus

ports = obd.scan_serial() print("###########") print(ports) print("###########") obd.logger.setLevel(obd.logging.DEBUG) # enables all debug connection = obd.OBD(ports[0]) # connect to the first port in the list cmd = obd.commands.SPEED # select an OBD command (sensor) response = connection.query(cmd) # send the command, and parse the response print(response.value) # returns unit-bearing values thanks to Pint print(response.value.to("mph")) # user-friendly unit conversions `

[ThomasMeister123]

So, I hat a working connection ONE time. With thise line: connection = obd.OBD(baudrate=None,fast=False, timeout=30)

Log:

[obd.obd] ======================= python-OBD (v0.7.1) ======================= [obd.obd] Using scan_serial to select port [obd.obd] Available ports: ['/dev/rfcomm0'] [obd.obd] Attempting to use port: /dev/rfcomm0 [obd.elm327] Initializing ELM327: PORT=/dev/rfcomm0 BAUD=auto PROTOCOL=auto [obd.elm327] Response from baud 38400: b'?\r\r>' [obd.elm327] Choosing baud 38400 [obd.elm327] write: b'ATZ\r' [obd.elm327] wait: 1 seconds [obd.elm327] read: b'\r\rELM327 v2.1\r\r>' [obd.elm327] write: b'ATE0\r' [obd.elm327] read: b'ATE0\rOK\r\r>' [obd.elm327] write: b'ATH1\r' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: b'ATL0\r' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: b'AT RV\r' [obd.elm327] read: b'14.2V\r\r>' [obd.elm327] write: b'ATSP0\r' [obd.elm327] read: b'OK' [obd.elm327] write: b'0100\r' [obd.elm327] read: b'\r\r>' [obd.elm327] write: b'ATDPN\r' [obd.elm327] read: b'A0\r\r>' [obd.elm327] ELM responded with unknown protocol. Trying them one-by-one [obd.elm327] write: b'ATTP6\r' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: b'0100\r' [obd.elm327] read: b'7E8 06 41 00 BE 1F B8 13 \r\r>' [obd.protocols.protocol] map ECU 0 --> ENGINE [obd.elm327] Connected Successfully: PORT=/dev/rfcomm0 BAUD=38400 PROTOCOL=6 [obd.obd] querying for supported commands [obd.obd] Sending command: b'0100': Supported PIDs [01-20] [obd.elm327] write: b'0100\r' [obd.elm327] read: b'7E8 06 41 00 BE 1F B8 13 \r\r>' [obd.obd] Sending command: b'0120': Supported PIDs [21-40] [obd.elm327] write: b'0120\r' [obd.elm327] read: b'7E8 06 41 20 80 05 A0 01 \r\r>' [obd.obd] Sending command: b'0140': Supported PIDs [41-60] [obd.elm327] write: b'0140\r' [obd.elm327] read: b'7E8 06 41 40 6A D0 00 00 \r\r>' [obd.obd] Sending command: b'0600': Supported MIDs [01-20] [obd.elm327] write: b'0600\r' [obd.elm327] read: b'7E8 06 46 00 C0 00 00 01 \r\r>' [obd.obd] Sending command: b'0620': Supported MIDs [21-40] [obd.elm327] write: b'0620\r' [obd.elm327] read: b'7E8 06 46 20 80 00 00 00 \r\r>' [obd.obd] finished querying with 73 commands supported [obd.obd] =================================================================== [obd.obd] Sending command: b'010D': Vehicle Speed [obd.elm327] write: b'010D\r' [obd.elm327] read: b'7E8 03 41 0D 00 \r\r>' 0.0 kph 0.0 mph

The I tried a second time (same code, restarted PI (car: ignition off, ignition on, started engine).

Log:

########### ['/dev/rfcomm0'] ########### [obd.obd] ======================= python-OBD (v0.7.1) ======================= [obd.obd] Using scan_serial to select port [obd.obd] Available ports: ['/dev/rfcomm0'] [obd.obd] Attempting to use port: /dev/rfcomm0 [obd.elm327] Initializing ELM327: PORT=/dev/rfcomm0 BAUD=38400 PROTOCOL=auto [obd.elm327] write: b'ATZ\r' [obd.elm327] wait: 1 seconds [obd.elm327] Failed to read port [obd.elm327] read: b'' [obd.elm327] write: b'ATE0\r' [obd.elm327] Failed to read port [obd.elm327] read: b'' [obd.elm327] closing port [obd.elm327] write: b'ATZ\r' [obd.elm327] ATE0 did not return 'OK' [obd.obd] Closing connection [obd.obd] Cannot load commands: No connection to car [obd.obd] =================================================================== [obd.obd] Query failed, no connection available None Traceback (most recent call last): File "/home/pi/Skripte/OBD.py", line 26, in print(response.value.to("mph")) # user-friendly unit conversions AttributeError: 'NoneType' object has no attribute 'to'

I dont get it ;(

[ThomasMeister123]

So, it works with THIS line:

connection = obd.OBD(baudrate=38400,protocol="6",fast=False, timeout=40)

But not with the default (auto-)Settings?

[gmaniak]

With this line connection = obd.OBD(baudrate=38400,protocol="6",fast=False, timeout=40) it works every time? Even when you do the restart procedure: rpi restart, ignition off, ignition on, engine on.

[csurf]

You have a weak or unstable bluetooth connection, or a bad adapter. I would first try manually connecting to the adapter serial port, rfcomm0, using a serial terminal application, and trying to manually send commands to the elm327 in order to see if you can easily establish a working connection & get valid responses to your commands. If not, then there's a problem with your link.