This morning, I was flying APM 3.2.1 in AUTO MODE, and was just out of control radio range . The telemetry signal was drifting in and out as well.
The last major message I got from Mission Planner was "MODE CHANGED TO LAND". I did NOT change the mode or want it to land! I tried everything to regain control, but to no avail (since it was out of radio range). At the time, it was over water and is now (presumably) at the bottom of the ocean.
I didn't see it, but I am making the assumption that it came down "nicely". And before anyone scolds me about non-VLOS: I was not in the US, as the log files will show.
The failsafes were set to land only when the voltage dropped below 12V, or when the GPS signal was lost. The log file shows that neither happened. Also, the MODE came in on channel 5. The log file shows that didn't change either.
Could someone please tell me what happened? Attached is a tlog file. I obviously don't have the dataflash log (it is at the bottom of the ocean), only the log from Mission Planner.
I need to know what happened. I don't want to lose $2000 in equipment again.
Replies
The actual GPS chips are about the same size in drones and phones, and the magnetometers are the same. The GPS antennas on drones are generally larger and tte larger the antenna, the better the signal. And although phones don't have 50 Amps running nearby, they do have a 1W (or so) transmitter at 700-800 MHz very nearby.
The GPS in my Samsung S5 is quite good. The magnetometer sucks.
It could prob be due to the fact that the magnetometers in drones are more sensitive than the ones on phones and that the GPS tracking devices or GPS modules attached to drones are more powerful than the ones in phones. Just from size alone you can kind of estimate the difference in sensitivity and tolerance.
I hear many complaining about bad GPS and magnetometer communication. So my question is - why do the GPS's and compasses in cell phones always work while the ones connected to flight controllers do not? Is is the wire length or the fact that they are unshielded in a noisy environment? Is it the quality of the compasses and GPS's? Is it the software serial ports on the flight controllers?
Has anyone put a 'scope on the lines to look at signal quality?
Can someone enlighten me?
I found it!
GPS signal lost.