Hey Kev, I hope you solved your "... I try to arm it and it does nothing." issue. If not, see if adjusting the " 'Stick Low' Threshold", as described below, solves the problem for you. It did for me. I came upon your thread when I experienced the similar "... set receiver to SBUS it reverts back to SPEKTRUM 1024 ..." behavior on my quad.
Some background information ... I bought an F3 EVO FC equipped brushed quad with an AC800 Rx in December 2016. The FC was flashed with "
BetaFlight/SPRACINGF3EVO 3.0.1 Oct 18 2016 / 10:36:44" (
BetaFlight: Board SPRACINGF3EVO) . I had been using the Chrome based BetaFlight Configurator (BFC). All was working well. The "... SBUS reverts back to SPEKTRUM 1024 ..." behavior occurred after I upgraded to the Windows based BFC (10.1.0). Flashing the FC with the latest available BetaFlight FW (
Flight controller info, identifier: BTFL, version: 3.2.4... -- Running firmware released on: Jan 10 2018 23:10:00) solved that problem. At this point, I have not restored the rate profiles (should not be too difficult by cut&paste of the CLI dump I made) but it is flying again.
I had the same "everything appears to work in BetaFlight but motors will not arm" behavior. I noticed that my throttle range (BetaFlight 'Receiver' tab; when Rx is bound and Tx is on) did not span the 1000-2000 (centered at 1500). I adjusted the " 'Stick Low' Threshold" (which was set below the lowest point of my throttle range) to be above the low end value of the range. Now the motors arm.
I also adjusted the "Stick Center" to the value that appears to be consistently at the mid point of throttle when the stick is at 50% travel. I will play with the Tx 'Outputs' (see below) as well going forward.
I know how to adjust the BetaFlight Rx ranges (and center point) using the OpenTX 'Outputs' on my Taranis X9D (so the BetaFlight values span the 1000-2000 range & center at 1500) when the Betaflight range values are outside (<1000 min & >2000 max) the 'normal' range but I don't know how to 'widen' the BetaFlight Rx range when these show as >1000 min & <2000 max.
Interesting that the min throttle drops to 885 when in failsafe.
Any who ... hope this helps.
Keep your (prop) tip ends clean! My Tx is calling "Inactivity alarm!"