Airspeed Sensor with Copter

Hi all,

I am working on a project using the PX4 on a helium balloon. Within this setup I want to control a gimbal using MAVLink commands. But in addition to this I would like to know the airspeed during flight, It appears these two things aren’t easy to achieve together. My current Pixhawk firmware is for a copter frame and works with the the gimbal, though doesn’t recognize the airspeed sensor. I can change the firmware to fixed-wing or VTOL but then lose all gimbal control parameters.

We have a Gremsy Pixy U gimbal and the Holybro Digital Airspeed Sensor (http://www.holybro.com/product/digital-air-speed-sensor/)

Is there anyway of achieving these two things together?

Many thanks!