ESP8266 Community Forum

- Sun Jul 05, 2015 3:05 pm #22509 Here is a good note on C vs C++

https://en.wikipedia.org/wiki/Compatibility_of_C_and_C%2B%2B

and whether or not the C programming language is object oriented ... the discussion on that one can be found (and should be taken to):

http://stackoverflow.com/questions/3241932/is-the-c-programming-language-object-oriented

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- Sun Jul 05, 2015 3:19 pm #22512 Getting back to the ESP::getFreeHeap(), if we look in the source code for the Ardunio IDE library, we find:

https://github.com/esp8266/Arduino/blob/esp8266/hardware/esp8266com/esp8266/cores/esp8266/Esp.cpp

and at line 127 we find that this is implemented as:

Code: Select alluint32_t EspClass::getFreeHeap(void)
{
    return system_get_free_heap_size();
}

The function call "system_get_free_heap_size()" is an ESP8266 OS function call that is documented in the Espressif SDK Programming Guide as "Get free heap size". We can google and search on this function and read more about it there. However, it seems that the core answer is that it returns the available heap size as understood by the ESP8266 operating environment.

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