crash in the file ocpp-config.jsn

[Aylaa1]

Hi @matth-x, I am using ESP-IDF in my project, During the start-up flow, after mocpp_initialise, there are sequence of files opened using the spiffs filesystem ws-conn.jsn, bootstats.jsn, ocpp-config.jsn and so on. However during subsequent restarts I'm having issues in writing content to ocpp-config.jsn. But the same issue is not observed with ws-conn.jsn, bootstats.jsn. When I investigated further, I found that when I try to write the value into the ocpp-config.jsn (like heartbeatInterval configuration), the appication crashes sometime, when json doc of capacity 1459 is passed to the function "storeJson" in 'ConfigurationContainerFlash::save()').

Thanks to support.

Regards, Aylaa

[Aylaa1]

Hi @matth-x , is there any update on this issue? could you please prioritize. Thank you, Aylaa

[matth-x]

Hi @Aylaa1,

To change configurations programatically, use the Configuration API like here:

https://github.com/matth-x/MicroOcpp/blob/735efa29805d33723d80cd351e4ca773b0d96a3e/tests/Metering.cpp#L98-L99

The first call gets a handle for the Config, the second call effectively changes its value. The same functions exist for strings and bools. You can see more usage examples in the file "Metering.cpp" I linked above.

Also #include <MicroOcpp/Core/Configuration.h> to get access to the Configuration API. Perform the changes after mocpp_initialize().

Manually manipulating the contents of the JSON files is without effect after initialization of the library. And before initialization it is risky, because I do not test such interaction with the firmware.

[Aylaa1]

Hi @matth-x, Thanks you for the response, the sequence you have mentioned is followed the same way, i.e., mocpp_initialize() is called first and later the configuration related apis. The actual problem is when the ocpp-config.json file is reaching the size above 1024(eg 1031), the application crashes. If I restrict the jsonCapacity to 1024 in (DynamicJsonDocument doc {jsonCapacity}), but the jsonCapacity calculated in the runtime is 1031, json file would be invalid and the application still crashes. The crash still persists if I increase the jsonCapacity to Max json capacity(4096). Basically I observe crash if I try to write anything more than 1024 bytes to ocpp-config.jsn file.

The problem does not occur, if I reduce the number of key-value pairs written to the ocpp-config.jsn file in such a way that the file size will not cross 1024 bytes.

(All other jsn files are below 1024 bytes except ocpp-config.jsn file, throughout the application like bootstats.jsn, ws-conn.jsn, sc-tx-1-0.jsn, ...)

PFA, the crash scenario log snips

Thanks, Aylaa

[matth-x]

Hi @Aylaa1,

Sorry, I'm still lacking an idea what could happen here. The most suspicious thing I see is that the application crashes due to a stack overflow. Normally, the stack stack size should rarely grow with payload data. Did you integrate a custom filesystem adapter which has payload buffers on the stack by any chance?

However, it is true that the default stack size in esp-idf is too small to run MicroOcpp. I increased it to 8192 in the example project:

https://github.com/matth-x/MicroOcpp/blob/735efa29805d33723d80cd351e4ca773b0d96a3e/examples/ESP-IDF/sdkconfig#L505