ROS interface with real quadrotor

Hi all,
I have built real quadrotor with Pixhawk which is working fine, my objective is to make working the real quadrotor with ROS. So i studied tutorial sitl interface with gazebo and ROS, which is working fine also. When i run a mavros python script the sitl running iris model inside the gazebo will takeoff and travels through way-point defined in scripts and finally it take land inside the gazebo simulator. I have interested to achieve the same with the real quadrotor too, but i don’t know how take forward this work. Can anyone please kindly help me to how to interface ROS with real quadrotor, it will be helpful for my project.

I suggest you to read this article :

To make it simple, you need a companion computer, which is connected to your Pixhawk. It can be an Odroid, a Raspberry, a Jetson etc.
You need to configure your Pixhawk in order that it accepts order from Mavros, with a specific baudrate.
Then, it is quite the same as Gazebo. You run mavros, with the specific USB port and baudrate.
And you have fun !

All of this is well documented in the arducopter website.
Do not hesitate if you have specific question.