Need help to use arduino as receiver on a quadcopter

i am trying to build a quadcopter which can be controlled by pc over wifi or bluetooth. I am now done with my quadcopter part and it works great but now i am stuck at a point where i want to control my quadcopter using arduino (as a receiver). It has KK2.1.5 flight controller, i successfully found a youtube link which demonstrate exactly the same but the code given in that video is missing something. Video is old so op is not replying to comments. I would be glad if someone can help me to figure out.

Youtube link - Arduino + KK2 - YouTube

Arduino Sketch - Free large file hosting. Send big files the easy way!

I have also attached the sketch i found in video description.

LeQuadForYoutube.ino (2.31 KB)

So you are using a hobby RC receiver now and it all works?
And now you want to remove the RC receiver and put in an Arduino to do something, but also take your PC input through some wireless signal and feed the same control board?

I am curious, what will the PC be doing in this scenario?