Using ArduPilot software (fixed wing, ArduPlane), I know that after I boot up I need to keep the system sit still while the gyros initialise.
When I have ground station in the field it's easy to know when it's safe to launch because the telemetry message tells me. But I don't always fly with a ground station. In these situations I currently just sit and wait for a while before arming, then again before launching.
Is there some reliable rule of thumb? information in the blinking of the arming switch or buzzing that I haven't worked out yet? This UAV has PX4 autopilot hardware (with both Px4FMU and PX4IOBoard), including with buzzer and illuminated arming switch. The LEDs on the board are obscured (but I could make light channels from them if required).
(Note: I'm asking this question here to test the theory that robotics stack exchange night be an appropriate forum for these sorts of questions, which has been suggested a couple of times in response to the Area51 drones proposal.)