Hi, first of all, I would try to have some commands running from code, i.e., a simple C/C++ program changing some GPIOs in a main. With such program, we can start working in its integration with thinger.io. The arduino instructions does not apply to the headers definitions, just for the resource definition and methods.
If you cannot control GPIOs natively with a C/C++ program, we can just issue system calls, i.e, for running a python command through the system call.
So, do you have some command or C++ program, without thinger, to control your GPIOs?