Send MAVLink commands from Raspberry Pi to Pixhawk

I have successfully established communication between Raspberry Pi and Pixhawk. Now I would like to send commands using a python/c/c++ script from the Raspberry Pi to the Pixhawk. It would be great if someone could guide me in the right direction. Thanks!!

P.S. I already have ROS Kinetic downloaded on my Raspberry Pi.

Hi @Dhruva_Bansal, did you manage to connect the Raspberry Pi with the Pixhawk 2.1? Could you please share with me how you connected the 2 devices? Thanks.