Crash on calling batteryVoltage()

[suoivilbo2]

Crash on calling batteryVoltage()

[jimwhitelaw]

I see this similar issue that occurred with an older version of ESP IDF. What version of ESP-IDF are you building with? From what I've been able to find, arduino-esp32 for Arduino IDE is using an older version (4.4.6) than the PlatformIO espressif32 framework (ESP-IDF 5.1.2). That might have an impact on your project.

[suoivilbo2]

Indeed, I am running the latest version of Arduino (2.3.2) which uses ESP-IDF 4.4. It's weird, because this bug shows up only when querying for batteryVoltage(). Other PIDs, e.g., rpm() run fine.

[jimwhitelaw]

If there's a way to use a newer version of ESP-IDF in Arduino IDE, that looks to be worth a try for you. (Or you could patch your local ESP-IDF with the change in (espressif/esp-idf@b43e777).

I don't know exactly what is happening and it could be completely irrelevant, but the batteryVoltage() request is bit different from other PID requests. It uses the "AT RV" command and the ELM327 returns the voltage it reads at its own power supply pin. There's no communication to the vehicle ECU for that request.

[Fichte79]

Hello The Problem is in the ELMduino.cpp in the function "float ELM327::batteryVoltage(void)".

If you uncomment the "payload = start + 4;" the error is gone.
Or Copy the complet function fron Ver. 3.2.0 in the 3.2.5

Is not the best way, but works ;)

[jimwhitelaw]

Reverting to v3.2.0 will re-introduce a bug where if the ECU returns "ATRV" as part of the response (as some do), then the value will not be parsed correctly. So be careful if implementing that solution. I believe that the payload = start + 4; code triggers the bug in ESP-IDF, but is not the root cause of the crash.

[Fichte79]

It may not be the root cause, that's why I said it's not the best way.
But it was only an update from 3.2.0 that caused the error and it is exactly this function that is responsible for it for me.
I use the programming as an emulator and on an ELM327 Bluetooth (China plug).
And things work fine in both systems.

[jimwhitelaw]

@Fichte79 or @suoivilbo2 are you able to test the PR I have just committed? I think it may be a fix, but I don't have hardware that exhibits the crash, so I can't test thoroughly. I can only test that the new code has not introduced a regression. Thx