Can't understand why value is 'None'

Jean--Michel commented 8 years ago

Hi,

Often, some messages have 'None' value.

[obd] Sending command: 014E: Time since trouble codes cleared
[obd] write: '014E1\r\n'
[obd] read: '7E8 04 41 4E 44 D8 \r\r'
r.time: 1466358933.57
r.name: TIME_SINCE_DTC_CLEARED
r.value: None

But sometimes it works:

[obd] Sending command: 014E: Time since trouble codes cleared
[obd] write: '014E1\r\n'
[obd] read: '7E9 04 41 4E 4B 9D \r\r'
r.time: 1466358933.7
r.name: TIME_SINCE_DTC_CLEARED
r.value: 19357

I tried to reverse the code to understand, but I failed. Could you please help me if you have some time?

Regards, jml

brendan-w commented 8 years ago

Somewhat strange. The reason it's reporting None is the difference between the 7E8 and 7E9 headers. The 8 vs. 9 are refering to ECU 1 vs. ECU 2. Python-OBD filters responses based on which ECU the command is designed for. Normally, Python-OBD only ever works with ECU 1 (7E8, the engine controller), but in your case, it looks like either ECU is allowed to respond to this command.

Even more curious, is why it chose 7E9 as the engine. This could indicate a problem in my ECU labeling logic, but that's a separate issue.

To fix it, mark the command as ECU.ALL, to prevent the 7E8 response from being filtered out:

import obd
from obd import ECU
obd.commands.TIME_SINCE_DTC_CLEARED.ecu = ECU.ALL

Thanks for the note, I'll look into that ECU labeling logic

Jean--Michel commented 8 years ago

For your information, I also saw 'None' values with the following messages (and may be some more) :

TIME_SINCE_DTC_CLEARED
CONTROL_MODULE_VOLTAGE
RUN_TIME_MIL
DISTANCE_W_MIL
ACCELERATOR_POS_D
THROTTLE_ACTUATOR
COOLANT_TEMP
ACCELERATOR_POS_E
INTAKE_PRESSURE
MAF
PIDS_C
RUN_TIME_MIL
EGR_ERROR
RPM
COMMANDED_EGR
FUEL_INJECT_TIMING
AMBIANT_AIR_TEMP

If you need some debug informations, I'd be happy to help.

Regards, jm

brendan-w commented 8 years ago

Yeah, if you could send me the complete debug data for this failure, it might tell me why it's choosing ECU 2. I tested the choosing logic on your debug from #50, and it worked correctly. Were you by any chance using a different car then?

Jean--Michel commented 8 years ago

Hi,

I think it's the same car, but I'm not sure, sorry about that. Please find attached a debug log. 04072016-c4jf.txt

IO also tried with another OBD software, it also detects two ECU (engine(7E8) and transmission(7E9)) and the same protocol as yours (ISO 15765-4 CAN (11-bit ID, 500 kBit/s). This sotfware log is following:

- OS version: Windows 7
- Succeed open comport
- comport setting detected
- Interface: ELM327 v1.4
- Vehicule voltage: 12.4V

- Protocol setting used: Automatic (auto-detection)
- Waiting for ELM initialization with ECU. Wait 10 secondes.
- Connecting to vehicule
- Protocol detected:ISO 15765-4 CAN (11-bit ID, 500 kBit/s)
- Scanning vehicule functionalities
- ECU detected at  0x7E9 address - Transmission
- ECU 0x7E9 Mode 1, PID : 80000011
- ECU detected at  0x7E8 address - Engine
- ECU 0x7E8 Mode 1, PID : 983B8013
- ECU 0x7E9 Mode 1, PID : 80018001
- ECU 0x7E8 Mode 1, PID : A019A011
- ECU 0x7E9 Mode 1, PID : 400C0000
- ECU 0x7E8 Mode 1, PID : 44DC0009
- ECU 0x7E8 Mode 1, PID : 00008041
- ECU 0x7E8 Mode 1, PID : 21100010
- ECU 0x7E8 compatible: EOBD
- ECU 0x7E9 compatible: EOBD
- ECU 0x7E9 Mode 2, PID : 58180000
- ECU 0x7E8 Mode 2, PID : 58390001
- ECU 0x7E8 Mode 2, PID : 20000000
- ECU 0x7E9 Mode 2 (Freeze frame) supported
- ECU 0x7E8 Mode 2 (Freeze frame) supported
- ECU 0x7E9 Mode 5 (O2 Sensor) not supported
- ECU 0x7E8 Mode 5 (O2 Sensor) not supported
- ECU 0x7E8 Mode 6, PID : 00000001
- ECU 0x7E8 Mode 6, PID : 80008001
- ECU 0x7E8 Mode 6, PID : 00000001
- ECU 0x7E8 Mode 6, PID : 00000001
- ECU 0x7E8 Mode 6, PID : 00000101
- ECU 0x7E8 Mode 6, PID : 00004001
- ECU 0x7E8 Mode 6, PID : 00000001
- ECU 0x7E8 Mode 6, PID : 20000000
- ECU 0x7E9 Mode 6 (OBDMID) not supported
- ECU 0x7E8 Mode 6 (OBDMID) supported
- ECU 0x7E9 Mode 7 (Not confirmed DTC) supported
- ECU 0x7E8 Mode 7 (Not confirmed DTC) supported
- ECU 0x7E9 Mode 8 (Actuator) not supported
- ECU 0x7E8 Mode 8 (Actuator) not supported
- ECU 0x7E9 Mode 9, PID : 10000000
- ECU 0x7E8 Mode 9, PID : 50200000
- ECU 0x7E9 Mode 9 (Vehicle info) supported
- ECU 0x7E8 Mode 9 (Vehicle info) supported
- ECU 0x7E9 Mode 9 (Vehicle info) supported
- ECU 0x7E8 Mode 9 (Vehicle info) supported
- ECU 0x7E9 Mode 10 (Permanent DTC) not supported
- ECU 0x7E8 Mode 10 (Permanent DTC) not supported
- Scan vehicle specific functions (Not compliant with OBD standard)
- Interface connected and initialized, ready to use.

I also join two screenshot of this software in cas it might help. Please, do not hesitate to tell me how I can help.

Thanks a lot for your time and software. jml.

Engine

obd1

Transmission

obd2

brendan-w commented 8 years ago

I've been mulling this one over for a while now, and have only had one thought; Were you using Async to perform those reads? I've seen one case where reads/writes trampled over each other and caused flaky behavior, (though I thought I fixed that). If you were, would you mind trying again with normal obd.query() and repeatedly sending a single, known-problematic command? Or, better yet, send me a copy of the script producing the error?

Other than that, I can't find any references to ECU's being allowed to respond in the place of another. An immediate fix for the problem (sorry I didn't mention this sooner), is to check for empty responses yourself:

if not response.is_null():
    # code...

JakubJD commented 5 years ago

Hi, I would like to ask, have you already fixed the troubles? I am struggling to connect to the car with elemntary command, but I usually get a answer command is not supported or none.

log file: Ports: ['/dev/ttyUSB0'] [obd.obd] ======================= python-OBD (v0.7.0) ======================= [obd.obd] Explicit port defined [obd.elm327] Initializing ELM327: PORT=/dev/ttyUSB0 BAUD=auto PROTOCOL=auto [obd.elm327] Response from baud 38400: '\x7f\x7f\r?\r\r>' [obd.elm327] Choosing baud 38400 [obd.elm327] write: 'ATZ\r\n' [obd.elm327] wait: 1 seconds [obd.elm327] read: b'ATZ\r\r\rELM327 v1.5\r\r>' [obd.elm327] write: 'ATE0\r\n' [obd.elm327] read: b'ATE0\rOK\r\r>' [obd.elm327] write: 'ATH1\r\n' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: 'ATL0\r\n' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: 'ATSP0\r\n' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: '0100\r\n' [obd.elm327] read: b'SEARCHING...\rUNABLE TO CONNECT\r\r>' [obd.elm327] write: 'ATDPN\r\n' [obd.elm327] read: b'A0\r\r>' [obd.elm327] ELM responded with unknown protocol. Trying them one-by-one [obd.elm327] write: 'ATTP6\r\n' [obd.elm327] read: b'OK\r\r>' [obd.elm327] write: '0100\r\n' [obd.elm327] read: b'NO DATA\r\r>' [obd.elm327] Connected Successfully: PORT=/dev/ttyUSB0 BAUD=38400 PROTOCOL=6 [obd.obd] querying for supported commands [obd.obd] Sending command: 0100: Supported PIDs [01-20] [obd.elm327] write: '0100\r\n' [obd.elm327] read: b'NO DATA\r\r>' [obd.OBDCommand] 0100: Supported PIDs [01-20] did not recieve any acceptable messages [obd.obd] No valid data for PID listing command: 0100: Supported PIDs [01-20] [obd.obd] Sending command: 0600: Supported MIDs [01-20] [obd.elm327] write: '0600\r\n' [obd.elm327] read: b'NO DATA\r\r>' [obd.obd] finished querying with 7 commands supported [obd.obd] =================================================================== Connection status: Car Connected Supported commands: GET_DTC GET_CURRENT_DTC CLEAR_DTC PIDS_A ELM_VERSION MIDS_A ELM_VOLTAGE [obd.obd] Closing connection [obd.elm327] closing port [obd.elm327] write: 'ATZ\r\n'

Can you give me an advi

ce please?

Thanks

Jakub

JakubJD commented 5 years ago

Hey,

I tried already one more time, still with failure.

Have you any ideas please.

Thanks

Jakub

alistair23 commented 5 years ago

@JakubJD There is no version 1.5 of the ELM327, so you are using a knock-off chip. The problem is probably that the knock-off chip doesn't correctly match the protocol. Please use a real ELM327 chip instead.

PS: In future please create a new issue for a new issue instead of commenting on a different problem. It makes it a lot harder to track.

JakubJD commented 5 years ago

Hey Alistair,

thanks for your answer. I have found under this link: https://www.carscanner.info/choosing-obdii-adapter/

the differences and I would like to choose this:

https://www.ebay.de/itm/Veepeak-OBDCheck-BLE-OBD2-Bluetooth-Scanner-Auto-OBD-II-Diagnostic-Scan-Tool-for/382722436111?hash=item591c08ec0f:g:jMUAAOSwWk5cN5vP

Can you me give an advice, please?

I will create a new issue in the future.

Thanks

Jakub

alistair23 commented 5 years ago

I don't know if that is a good one or not, I can't really give you a recommendation. Just make sure that it uses a real ELM327 and you should be ok.

I have used this one: https://www.sparkfun.com/products/9555. It's actually a STN1110 instead of ELM327, but it is compatible and works for me.

Besides that I have a custom PCB with an ELM327 that I use.

JakubJD commented 5 years ago

Hi Alistair,

I would like to ask you one more time, whether you can help me. I bought the OBD Adapter: Obdlink LX Bluetooth: https://www.amazon.de/gp/product/B00H9S71LW/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 , after your advice.

But I have still the problems, that I get the answers, that command is not supported. Have you any idea yet? Thanks a lot

Jakub

brendan-w / python-OBD

Can't understand why value is 'None' #51

Engine

Transmission