ESP8266 Community Forum

- Wed Feb 03, 2016 12:55 am #40329

If I parse a ~4k characters json string ESP8266 keeps rebooting with strange stack overflow errors fired over the serial port.

Sounds to me like your problem is not insufficient RAM, but you are trying to allocate a huge array on the stack. Using heap instead should fix that problem, i.e. not

Code: Select allchar buf[4096];

but

Code: Select allchar *buf = new char[4096];
// do stuff with buf...
delete[] buf;

- Wed Feb 03, 2016 5:25 am #40339 In resource limited environments (like on a microprocessor) it is often better to make sure memory allocation and use is predictable. That means: don't allocate memory on the stack but neither do it on the heap. Do it statically like this: static char buffer[4096]. That way you will never have the surprise of memory full (which includes an overwritten stack -> crash). Memory allocated like this will not end up in the image, only the symbol itself; the image will not get larger.

You may want to define a large buffer once and use it at various places, to save memory.