QuadPlane Frame setup¶
The QuadPlane code supports several frame arrangements of quadcopter, hexacopter, octacopter and octaquad multicopter frames.
The motor order and output channel is the same as for copter (see Copter motor layout) except that the output channel numbers start at 5 instead of 1.
For example, with the default Quad-X frame the motors are on outputs 5 to 8. The arrangement is:
- Channel 5: Front right motor, counter-clockwise
- Channel 6: Rear left motor, counter-clockwise
- Channel 7: Front left motor, clockwise
- Channel 8: Rear right motor, clockwise
You can remember the clockwise/counter-clockwise rule by “motors turn in towards the fuselage”, except for the H configuration, there all directions are inverted!
Another common setup is an octa-quad, which uses the following ordering
- Channel 5: Front right top motor, counter-clockwise
- Channel 6: Front left top motor, clockwise
- Channel 7: Rear left top motor, counter-clockwise
- Channel 8: Rear right top motor, clockwise
- Channel 9: Front left bottom motor, counter-clockwise
- Channel 10: Front right bottom motor, clockwise
- Channel 11: Rear right bottom motor, counter-clockwise
- Channel 12: Rear left bottom motor, clockwise
You can remember the clockwise/counter-clockwise rule for an octa-quad by “top motors turn in towards the fuselage, bottom motors turn out away from the fuselage”.
The normal plane outputs are assumed to be on 1 to 4 as usual. Only vertical lift outputs (5 to 8 on a quad setup) run at high PWM rate (400Hz). In a quad setup you can also use channels 9 to 14 in any way you like, just as with the normal Plane code.
You can optionally move the quad motors to be on any other channel above 4, using the procedure outlined below.
To use a different frame type you can set Q_FRAME_CLASS and Q_FRAME_TYPE. Q_FRAME_CLASS can be:
- 0 for quad
- 1 for hexa
- 2 for octa
- 3 for octaquad
Within each of these frame classes the Q_FRAME_TYPE chooses the motor layout
- 0 for plus frame
- 1 for X frame
- 2 for V frame
- 3 for H frame
Using different channel mappings¶
You can remap what output channels the quad motors are on by setting values for RCn_FUNCTION. This follows the same approach as other output functions.
Note that you do not need to set any of the RCn_FUNCTION values unless you have a non-standard motor ordering. It is highly recommended that you use the standard ordering and do not set the RCn_FUNCTION parameters, leaving them at zero. They will be automatically set to the right values for your frame on boot.
The output function numbers are:
- 33: motor1
- 34: motor2
- 35: motor3
- 36: motor4
- 37: motor5
- 38: motor6
- 39: motor7
- 40: motor8
So to put your quad motors on outputs 9 to 12 (the auxillary channels on a Pixhawk) you would use these settings in the advanced parameter list:
- RC9_FUNCTION = 33
- RC10_FUNCTION = 34
- RC11_FUNCTION = 35
- RC12_FUNCTION = 36