Please see the course late policy in the syllabus. Almost all extensions should be handled through this mechanism. Exceptions will need a note from the Dean. However if you have a problem, we encourage you to reach out to the Office of Student Life, as they can help in many other ways as well.
Come to office hours and we will try to help! It is useful to debug piece by piece. Does it power on? Can you fly with the RC controller? Can you connect to the Pi? Do all the sensors work?
If you have a question that pertains to the rest of the class, please post it on Piazza. Otherwise, please contact the TA list (cs1951rtas@lists.brown.edu) or the HTA list (cs1951rheadtas@lists.brown.edu).