Question 1: I would like to consider the Pixhawk for flying a small quad, but without compass or GPS. I know they are offering it for sale without those modules, and I understand I don't get any nav features. What I want is IMU stabilization mode, manual mode, and a failsafe mode to center sticks. I may add GPS later, but I just want to start out with basic flying capability and not have the firmware freak out because of missing data.
Question 2: I would like to use the Spektrum PPM input, but I see only one connection for that. I would like to use multiple Spektrum satellites in order to get some antenna orientation diversity. Any way to do that? Any disadvantage of using a regular Spektrum receiver such as AR8000, and plugging all the signals separately as PWM?
Replies
On your question 1, I should think you would be able to fly without a compass and GPS just fine. As you say, you will just be missing all the nav functions. I haven't done it with Pixhawk, but I have flown a quad on PX4 without them. I've also done plenty of flying with APM with a non-functional GPS or Compass. Stab works just fine.
The only thing would be if you are doing high-speed flying, banking and turning, without the GPS feedback into the AHRS solution, sometimes the angles go off a little bit. It's fairly minor, and if you just don't fly like that, it's fine.
How well does Stab work without a Compass? Will the yaw angle drift quickly?
I never ended up doing this without the compass and mag. I ended up getting the whole kit.
However in STAB mode it does not use the GPS and mag, only the IMU, and it is fine. I maintains it's yaw, pitch, and roll very well. Maintaining altitude though is not very good due to pilot skills. I suppose I should use ALT HOLD mode more...