By all means go to the interview.
Having said that, that is not the job for which you've a foundation. It sounds like an Analog Application Specific Integrated Circuit (ASIC) design job, with ability to write low-level hardware code. If he has read your resume he knows your background is in mechanical engineering. If I were to guess, you would have to work on the mechanical design of the drone, wingspan, airlift, payload size and hull integrity etc. You would define the physical constraints in light of the target application and then the other engineers would design the electrical components. You may end up being an Electro-Mechanical engineer, perhaps participating in the design of electronics surrounding the mechanical parts of it all.
You cannot learn all the facets of a different field from one book in one weekend, you may catch a few phrases but an experienced professional will see right through you. This will make you look very bad. What I found to be most effective, is to know well what you claim to know, everything that you listed in your resume. At the end of the day its confidence in your own knowledge that helps you carve your waves.
Worst case scenario you're not a good fit. You will have at least gained two things, first-the experience of an interview, two-the knowledge of what you don't know.
I hope this helps.