Hi: stoopid newbie [to Arduino] question I'm afraid. We have a pre-existing source tree of multi-platform (ESP-IDF, nRF5 [GCC/SES], STM32F4, Zephyr] code in which the C source files are quite separate, "out of tree", from the metadata that builds those source files. In other words there is no
src directory inside the SDK directory structure; there can't be because the code is intended to be compilable using [wildly!] different SDKs.
Since ESP-IDF is delivered as part of the Arduino tool-chain, and we support ESP-IDF, we have the opportunity to build our code with Arduino, allowing customers to use both our plain-old C code APIs and the Arduino APIs side by side.
However, I haven't found an example of the Arduino library format in which the source/header files are scattered around in variously named directories, ones that are NOT inside the library directory tree.
Can anyone point me at an example of how to do this?