Hello, I'm new here but am hoping to learn a lot in a relatively short amount of time. I am helping on a VTOL model aircraft with 8 lift fans and 2 forward propulsion fans. I have read about and downloaded/installed QGroundControl v3.1.3 on my Win7 PC and have started and succeeded in loading the Standard VTOL firmware onto a Pixhawk to try to get some familiarity with this part. Ultimately, after learning how, I will want to be able to either modify existing firmware (i.e. like the Standard VTOL firmware) or create firmware to allow me to create a custom version to use with a model my colleague is putting together (he knows the hardware and has built and flown drones before, but I'm more of a theoretical type that has some general experience doing computer models, simple coding/nothing extensive, etc.).
I am quite a noob at Pixhawk/QGroundControl though and am asking for some guidance on how to do this kind of code development. Can you please tell me the process by which I could start this? I'm thinking of starting simple at first; take an existing VTOL firmware from whatever code it starts from, making a very minor tweak to it to make it "custom", then compiling (or whatever is done to enable it for QGroundControl), and then upload the "custom" firmware into QGroundControl and then the PixHawk. I just need some step-by-step instructions (and preferably a good example to go by) with more specifics on the more basic steps that what's shown in https://docs.qgroundcontrol.com/en/ on how to accomplish this as simply as possible. Most of what I've found out there seems to assume one already has experience with this and so doesn't show these more basic steps. Can you please help? I apologize if its already available somewhere and I haven't found it yet.