@Vanja_APD: I think it was a connection issue. When I took it all apart, I found the servo cables slightly loose. Replaced the connectors and put them back in and the motor stutter is gone. Not sure if that can cause the motor direction to change but I will do some more tests and confirm.
@xfacta: I am getting 6 notches at fundamental and then for two more harmonics. That is a total of 6 * 3 * 3 = 54 notches, which is the current max supported. It’s strange because I was told only 4 motor inputs would work but there you go. ESC telemetry is working as well.
I know you mentioned the BATT_FS_ stuff to me before. I haven’t changed it yet because I keep getting low voltage warnings during my manual tune hover tests and I am not sure what the behavior will be in that case. Does it do a RTL or Land during Alt Hold? What if it happens during Autotune?
Have you got the latest .bin log to see what’s going on with the battery?
I find that using the correct params as calculated by the Initial Parameters and getting early fail safes means you have
the voltage calibration wrong (or there’s more resistance somewhere than you expect)
the battery is worse than you expect
Disabling the failsafes only leads to bad outcomes or the battery keeps getting worse and worse.
It will do RTL if you have that set as the action, but if it is within the (inverted) “Cone Slope” it wont rise to RTL altitude before returning to home, essentially just repositioning and landing.
RTL_CONE_SLOPE,3 = 3 vertical distance unit for every 1 horizontal distance unit = a steep inverted cone, easy to be outside this cone meaning climb to full RLT Alt !
RTL_CONE_SLOPE,1 = 1 vertical distance unit for every 1 horizontal distance unit = very shallow inverted cone, easy to be inside the cone but be aware of obstacles
I use:
BATT_FS_CRT_ACT,1
BATT_FS_LOW_ACT,2
RTL_ALT,4500
RTL_ALT_FINAL,0
RTL_CLIMB_MIN,200
RTL_CONE_SLOPE,2
Direction changes will occur if one of the phase cables is not connected correctly (ESC needs 3 phases to maintain control in the desired direction), or a phase is damaged. Given it’s intermittent, it would point to a connection issue (the nice part about power electronics is that it either works or doesn’t).
Thanks, Shawn. So far, I have seen little reason to doubt my battery. It is a new battery and I have just started using it. I think I get battery warnings if the starting voltage was medium or low and there is a sudden but transient voltage drop due to throttle. See ESC voltage plot here.
I have noted your concerns about it and will enable these settings when I move on to full Auto missions. I just don’t want any unexpected behavior when doing tuning flights.
P.S. Did hover test today. It worked fine, save for my current outstanding PID issue so this ESC problem seems to be resolved.