Thanks for the reply, @hek. Maybe here we can take things one at a time. For a first step, would building the GWs as MQTT allow connections through a broker such that multiple GWs will work? "Arduino compiler" is bad shortcut name. I meant that there is some transformation arduino does to the code before it reaches the gcc compiler. This is what i want to avoid and have my code work with gcc directly, even if using arduino core/libraries.