I used and extended the ArduPilot code for an approach to a special FPV issue:
'Where should I put my FPV AV-TX antenna'
In down position video transmission is often better than in up position.
But hey, bad news, sometimes we have to land...
So I came to the solution of toppling the antenna.
The test flight video shows the Barometric Antenna Toppler - B.A.T. - in action.
The antenna is toppled down when the plane is above 25m and toppled up when it's below 20m.
(Values can be changed.)
The toppling is controlled by an ArduPlane software extension using the barometric sensor.
Toppling is also possible manually e.g. for ground testing.
This video shows the B.A.T. in my Rookie testship:
Next step is the integration in the left wing of my Knurrus Maximus FPV.
There the antenna will topple through the nose edge of the wing.
By the way, this is my first homebrewed CloverLeave antenna build with informations from IBCrazy and calculations from rcexplorer.se.
Putting it upside down inside the fin would have been harder?