Came across more clues to fly-aways. The camera and other sources of interference.
Here's a video showing how one GoPro camera affected the number of satellites on a Garmin, even when Wi-Fi was off. Turn on the camera - number of satellites goes down. Some GoPros affect satellites and some don't.
The test showing the camera affecting the number of satellites begins at 0:44.
https://www.youtube.com/watch?v=-cMESqwBz9U
It was recommended to cover the GoPro with either tin foil or copper sheet foil to block interference. Some even line the bottom of the bird. Here are the templates.
http://www.hovership.com/2013/03/26/shielding-a-gopros-emi-rf-noise/
Sometimes the camera cable acts as a dipole antenna. Change its direction so the dipole effects don't interfere with GPS.
http://diydrones.com/forum/topics/using-camera-wipes-out-gps-signal-entirely-confirmed
This site goes through sources of interference.
http://copter.ardupilot.com/wiki/common-diagnosing-problems-using-logs/
Which led to learing how to read the telemetry and dataflash logs (of another brand) to diagnose problems.
It goes into:
- Mechanical
Vibration
Compass interference:
- Interference from the power distribution board, motors, battery, esc and other electrical devices near the APM or PX4 can throw off the compass heading
GPS Glitches
Power Problems
Unexpected errors including failsafes:
- Throttle failsafe,
GPS failsafe,
GCS (Ground Control Station) failsafe,
Battery failsafe.
Fence failsafe
For more details on compass interference:
- Natural & artificial magnetic anomalies warning which distort the magnetic field in which I am flying.
- What is the Safe distance for various objects and materials during compass calibration i.e. at 6" it includes metal rim glasses, metal watch band, etc.
What increases the magnetic field thus increasing the interference?
http://copter.ardupilot.com/wiki/automatic-compass-declination/
Also includes: What hardware changes can you make to reduce magnetic interference?
- Placement
Power Distribution Board
Wires between the PDB, ESCs and battery as short as possible + other tips about wires.
I now have more ideas of what to do in order to avoid a fly-away.