We have an Iris+ with a pixhawk which had the AC3.2.1 firmware that we updated to AC3.6.9. On updating we found that we were unable to calibrate the ESC. We tried two methods, 1) Calibrating ESC from Mission Planner 2)All at one Calibration. When the throttle was up, and battery connected, it would go into the ESC calibration mode(red,blue,green LEDs ina cyclical pattern) and then we disconnected , reconnected and pressed the safety switch on. It would still be in the calibration mode but none of the calibration beeps would be heard. On pulling the throttle down nothing would happen either. The motors would not start either.
We went back to AC3.2.1 and were able to calibrate the ESC. Do we need to calibrate the ESC every time there is a firmware upgrade or only the Accel and Compass need to be Calibrated ?
P.S we updated to AC3.6.9(v3) in order to get the GRIP_ENABLE parameter ref this. However we were not able to calibrate the ESC in AC3.6.9(v2) or AC3.6.9(v3)
Right now we are calibrating the ESC on 3.2.1 and then updating to 3.6.9 to enable the rest of the features. Is this an expected outcome and do you recommend a better way to tackle this? Since we are not sure if the ECS would need re calibration when the firmware updates