I dusted off my venerable Phantom 3 Pro after more than a year during which the RC controller’s failure to accept a charge confounded me. Finally, I stumbled across a YouTube video showing how to dismantle the Phantom 3 Pro’s RC controller to briefly disconnect the controller’s battery wiring harness, which solved the controller charging problem instantly.
With the controller fully charged at long last, I launched the drone for a 5-mile test flight using a spiral Litchi waypoint mission that ascended to 750 feet AGL before circling back down on the spiraling descent to the launch point. Oddly enough I noticed that while the Phantom 3 Pro followed the Litchi waypoint flight path with the usual precision I have come to expect, the drone slowly rotated in the horizontal yaw axis for the entirety of the flight in complete defiance of the camera headings I stipulated during the creation of that Litchi waypoint mission. At the same time, the camera’s horizon tilted and skewed randomly in a violent manner that rendered the resultant video footage unwatchable.
Suspecting calibration issues, I went the whole hog and meticulously calibrated the Phantom 3 Pro’s GPS, compass, IMU, and camera gimbal. Before the calibrations were done, I had already noted that the instant I took manual control over the Phantom 3 Pro to interrupt a Litchi waypoint mission, the uncommanded airframe rotations in the yaw axis ceased, whereby the drone flew with buttery smooth 3-axis stability, responding with unerring precision to all my control inputs, and displaying none of the odd camera horizon tilting motions that occurred while the drone was flying an autonomous Litchi mission.
My next test entailed flying the drone with DJI Go, and to my astonishment, the drone flew and filmed with rock-steady stability of both drone and camera. The uncommanded yaw rotations stopped, as did the wild camera failings that occurred when the same drone was flown under the autonomous control of Litchi during waypoint missions.
I have never heard of a drone that flies perfectly while being manually flown with Litchi OR with DJI Go, yet, will yaw uncontrollably when flown autonomously under the control of Litchi. Having carried out all the usual calibration procedures as prescribed in the DJI Go settings instructions, and having seen this drone fly perfectly in all regards when used with DJI Go, I am baffled as to why that same uncommanded yaw only occurs when I use Litchi to control the drone’s waypoint flights.
Any ideas regarding this puzzling mystery would be appreciated. Being a die-hard conspiracy theorist, I cannot shake the suspicion that DJI might have a reason to booby-trap their firmware to ensure that some of their older drone models fly erratically when controlled with Litchi, despite operating perfectly while under DJI Go control. I hope this speculation is wrong and that a practical solution to this predicament can be offered by someone more knowledgeable than I am in these matters. Thanks in advance for any hypotheses that can be shared here.