This is my third crash (repeating the 'exact' same scenario deliberately) in the past two days. I have found the core problem of the issue -> Using camera (RPi camera module) on-board the flight wipes out GPS signal 'entirely'.
Here is my setup:
- Autopilot board: 3DR's APM 2.5, with ublox GPS module, 3DR Telemetry EU (900 MHz), RC Txm/ Rx (Flysky) Spread spectrum/Freq.hop ?
- Networking harware (with WiFi): Raspberry PI + camera module + Edimax WiFi dongle.
- The two boards are NOT interfaced with each other. I am jsut powering up RPi from one of the ESC's BECs 5V.
- I just made a shielding for this problem. Improves but with uncertainty (more on this later).
As far as I could see, I could (luckily) not find interference on 2.4 GHz of Txm/Rx and the WiFi (802.11 b/g/n) that I was initially expecting.
But to my surprise, what happens is as soon as I start shooting the video, the 'satcount' goes to 0 for about a few seconds and then starts getting back to normal. Originally I have satcount of 9.. drops quickly to 0 as soon as I start the video shoot and then slowly increases to 7 until video footage is completed.
When the satcount reduces, copter goes CRAZY (yes, literally crazy), 'does not land' but flies away to some remote corner and crashes before I could take back control (Log attached shows the glitch clearly). I cross checked that this happens only in LOITER mode when taking the video; Loiter uses the GPS. Shouldn't it land, when copter loses GPS fix (for 5 seconds)??
I did ground tests without flying, just commanding the video to start, brings down satcount to 0, as seen in Mission Planner.
I used Aluminium shielding, it helps quite a bit, but may make copter drift during flight video unreliably. The cause may also be the camera + camera cable.
I wonder how can this be possible in the first place. uBlox GPS uses 1.575GHz carrier wave and such a popular RPi camera module should come with ISA interference certificate/clearances, I am completely bamboozled!!! Another post issuing similar problem but with HK camera here.
Below is my latest setup, still some glitches in satellite count, but yet not the perfect solution. Glitches in satcount is 1 to 3 during video shoot. Did anyone faced this? Looking for a neat solution.
Any suggestions are welcome.
Thanks and regards,