Will not arm with rudder from TX if throttlefs is enabled

I posted an issue on Github list…can only arm via GCS if Throttle FS is enabled…

Please post a log demonstrating the problem

arming via rudder does work with throttle failsafe enabled. As Craig suggests you could post a log and perhaps we can work out why you can’t arm.
Cheers, Tridge

here is the log…

power plane no tx on
connect MP
is in disarmed,failsafe (thr=~987…fs set at 1000)
turn on TX,failsafe goes away (thr =~ 1100)
arm via MP (okay)
disarm via MP (okay)
low throttle, full rudder left for 6 seconds [color=#FF0000](no arm)[/color] PWM 2012
then full right for 6 secs (no arm) PWM ~980

[quote=“hwurzburg”]here is the log…
Thanks, and sorry for taking so long to look at it.
The problem is your RC3_MIN value. In the log your RC3_MIN is 986. When you tried rudder arming the throttle was at 1117, which is about 10%. The throttle needs to be within the dead-zone of zero to arm (so the motor doesn’t start immediately!).
Perhaps when you did your RC calibration your throttle trim may have been a bit lower than it is now?
Cheers, Tridge

Thanks!I did RC calibration as it was asked for…move all sticks to their lowest/highest positions…986 is the lowest…what is sent for low throttle fs from my RX failsafe setup…normal non fs low throttle is ~1100 and the motor starts just above that…and the fs trip point is set at 1000…then cal the esc for nonfs low throttle to max throttle range…that is what I did…

normally, low throttle fs is set on other systems(RVOSD for example) in this same manner…it allows all radios/setups to be used with a low throttle fs function…including those that want to engage it with throttle trim lever

a note should be added to the wiki that throttle must be within +/-10% of RC3_MIN for arming to occur in all cases…and that therefore FS_THR must be set [color=#FF0000]BELOW [/color]RC3_MIN

I will readjust and try again…PS I note that in disarmed state I found that the APM sent PWM 900 to the motor…I would have expected RC3_MIN…although having the ESC constantly beeping in DISARM may be a nice feature (or may be extremely irritating on the bench :wink: )

changing RC3_MIN to 1100 worked…thanks…still need a wiki caution or a note that FS_THR can be set below RC3_MIN value obtained during calibration and that rudder arming only occurs if throttle is within +/-? % of RC3_MIN…

thanks again

That is controlled by the ARMING_REQUIRE value. See the wiki page that explains it in more detail. Your log shows ARMING_REQUIRE=2, which means it puts out zero PWM, and the ESC beeps. Changing it to ARMING_REQUIRE=1 will make it send RC3_MIN instead.
I also agree that we should add a note about RC3_MIN being the mimimum normal flight throttle level, not the failsafe level.
Cheers, Tridge

Thanks…unfortunately,I was going by what the MP states for that:

“Arming disabled until some requirements are met. If 0, there are no requirements (arm immediately). If 1, require rudder stick or GCS arming before arming motors and send [color=#FF0000]THR_MIN PWM[/color] to throttle channel when disarmed. If 2, require rudder stick or GCS arming and send [color=#FF0040]0 PWM [/color]to throttle channel when disarmed. See the ARMING_CHECK_* parameters to see what checks are done before arming. Note, if setting this parameter to 0 a reboot is required to arm the plane. Also note, even with this parameter at 0, if ARMING_CHECK parameter is not also zero the plane may fail to arm throttle at boot due to a pre-arm check failure.”

I assumed (always a danger!) that “0 PWM” actually meant RC3_MIN… and THR_MIN PWM if set to 0 would be low throttle (ie RC3_TRIM…ie setting with low throttle during cal)…instead of actually RC3_MIN for the former and 900us for the latter…

probably should be changed in MP…