Add AERT mixer

ROMFS/px4fmu_common/mixers/AERT.main.mix

@@ -0,0 +1,81 @@
+Aileron/rudder/elevator/throttle mixer for PX4FMU
+==================================================
+
+This file defines mixers suitable for controlling a fixed wing aircraft with
+aileron, rudder, elevator and throttle controls using PX4FMU. The configuration
+assumes the aileron servo(s) are connected to PX4FMU servo output 0, the
+elevator to output 1, the rudder to output 2 and the throttle to output 3.
+
+Inputs to the mixer come from channel group 0 (vehicle attitude), channels 0
+(roll), 1 (pitch) and 3 (thrust).
+
+CH1: Aileron mixer
+-------------
+Two scalers total (output, roll).
+
+This mixer assumes that the aileron servos are set up correctly mechanically;
+depending on the actual configuration it may be necessary to reverse the scaling
+factors (to reverse the servo movement) and adjust the offset, scaling and
+endpoints to suit.
+
+As there is only one output, if using two servos adjustments to compensate for
+differences between the servos must be made mechanically.  To obtain the correct
+motion using a Y  cable, the servos can be positioned reversed from one another.
+
+M: 1
+O:      10000  10000      0 -10000  10000
+S: 0 0  10000  10000      0 -10000  10000
+
+CH2: Elevator mixer
+------------
+Two scalers total (output, roll).
+
+This mixer assumes that the elevator servo is set up correctly mechanically;
+depending on the actual configuration it may be necessary to reverse the scaling
+factors (to reverse the servo movement) and adjust the offset, scaling and
+endpoints to suit.
+
+M: 1
+O:       10000   10000      0 -10000  10000
+S: 0 1  -10000  -10000      0 -10000  10000
+
+CH3: Rudder mixer
+------------
+Two scalers total (output, yaw).
+
+This mixer assumes that the rudder servo is set up correctly mechanically;
+depending on the actual configuration it may be necessary to reverse the scaling
+factors (to reverse the servo movement) and adjust the offset, scaling and
+endpoints to suit.
+
+M: 1
+O:      10000  10000      0 -10000  10000
+S: 0 2  10000  10000      0 -10000  10000
+
+CH4: Motor speed mixer
+-----------------
+Two scalers total (output, thrust).
+
+This mixer generates a full-range output (-1 to 1) from an input in the (0 - 1)
+range.  Inputs below zero are treated as zero.
+
+M: 1
+O:      10000  10000      0 -10000  10000
+S: 0 3      0  20000 -10000 -10000  10000
+
+CH5: Flaps mixer
+------------
+Flaps are controlled automatically in position control and auto
+but can also be controlled manually
+
+M: 1
+O: 5000 10000 0 -10000 10000
+S: 0 4 10000 10000 0 -10000 10000
+
+Ch6: Landing gear mixer
+------------
+By default pass-through of gear switch
+
+M: 1
+O: 10000 10000 0 -10000 10000
+S: 3 5 10000 10000 0 -10000 10000