RaspberryPilot is an open-source project, if you are interested in making a quadcopter by raspberry pi, this project may be helpful to you.
Video:
Circuit:
RaspberryPilot is controled by RaspberryPilotApp (https://github.com/jellyice1986/RaspberryPilotApp) with Android phone, there are two type of radio communication system as below
Type 1: communicat by using the blutetooth on smart phone, the communication range is about 10 meters
Type 2: a 433 MHZ and 2.4 GHZ signal converter between RaspberryPilot and Android phone, the communication range can reach 200 meters