Companion Computer Raspberry Pi for 23 PWM signals

Hello,

I am developing a tilt rotor VTOL. Where I need somewhere around 22-23 PWM outputs.

I am using pixhwak 6C which provides 16 out of the box PWM singnals.

For these reason, i decided to use a companion computer (Raspberry PI) to have additional PWM outputs.

I have been looking around on internet on How to receive specific data from the flight controller via MAVlink or any other protocol to Raspberry Pi?

In my case, i want to receive some data from the flight controller like airpseed, current mode, transition initiation etc. and based on that generated PWM outputs for specific servos via Raspeberry Pi.

I will uses all 16 outputs from PX 6C. The Raspberry Pi is only for additional 6-7 servos.

Is there any example for data retrieval from PX4 controller to Raspberry Pi via MAVlink or any other protocol??

Any other help would also be appriciated.

Thanks.