I'm making an experimental aircraft using the stock PX4 multicopter code. However, the ESCs I'm using are reversible, i.e. PWM 1500µs is stopped, 2000µs is full up and 1000µs is full reverse. In order to make this work, I've made a custom airframe and mixer; I've pasted the first motor output mixer below. PWM_DISARMED is set to 1500, and my throttle stick is sprung to centre. I'm not using any auto functions - only stabilise mode.
Now, my problem is, that about 60% of the time, when I arm, the motor output shoots to 1000µs for half a second or so, then back to 1500µs, where my stick is. This causes the motors to spin in full reverse momentarily upon arming. Very scary!
The logs didn't show anything on OUT0_Out0, but I did discover that if I activate the kill switch, then arm, the motor waits until I deactivate the kill switch, then they spin up momentarily. and allows it to be captured by the logs.
Does anybody have any idea what's going on? Any help would be much appreciated!
O: 10000 10000 0 -10000 10000
S: 3 0 10000 10000 0 -10000 10000
S: 0 3 -20000 -20000 10000 -10000 10000