There might be more than one way this can happen, but one of the ways it can happen is if you have a function that has local variables whose size exceeds the maximum stack size for the Arduino you are targetting.
In some cases, it can mean that you are asking for local variables larger than the entire memory of the Arduino. In other cases it can mean that the stack size is configured for smaller than that and you have exceeded the configured stack size.
It is not uncommon for a stack size to be configured when building programs. When you build a program, you are always having to balance between:
- the stack
- space for dynamic memory allocation
- space for the code itself
- space reserved for linking libraries
Some systems allow you to adjust the balance.
It is common that systems are configured so that the stack starts at one side and dynamic memory starts at the other side and they grow towards the middle. If you are working on an embedded system, there would not be any dynamic link libraries, and in theory you would not need to configure a maximum stack size for the purpose of reserving space for the dynamic libraries. On the other hand when you are using embedded systems it is often in the context of needing a guarantee that the program will never run out of stack space, so a maximum stack size is often configured anyhow...
