Flight Controllers (Pro)
What is so special about a Flight Controller?
Quadcopters are complicated machines when you think about it. Imagine trying to balance a ball bearing in the middle of a tray whilst walking over uneven ground. That is essentially what the quadcopter's Flight Controller is doing. The Flight Controller senses the corrections that are required to maintain stabilised flight, and constantly adjusts the power delivered to each motor to achieve this. On top of this, it overlays the pilot's commands, and further adjusts the power to particular motors to achieve this.
DJI Quadcopter and Drone Flight Controllers
DJI are the industry standard bearers when it comes to controlling your quadcopter, with a variety of models to fit your requirements.