A fully functional quadcopter with the Arduino Microcontroller, IMU, Electronics and C++ programming Language
This code here is derived from Joop Brokking (http://www.brokking.net/)
I made a few tweaks to build and fly to my taste.
Well, Joop's Explanations were great, but a little technical for me. I had to rewatch a ton of times especially the IMU section.
You might like my overview