APM 2.6 Flight Controller

The APM Flight Controller

The full Open source Flight controller system.

Features:

• It allows the user to turn any multirotor, fixed, rotary wing, cars and boats into a fully autonomous vehicle; capable of performing programmed GPS missions with way points.
• This revision of the board has no onboard compass, which is designed for vehicles (especially multicopters and rovers) where the compass should be placed as far from power and motor sources as possible to avoid magnetic interference. (On fixed wing aircraft it’s often easier to mount APM far enough away from the motors and ESCs to avoid magnetic interference, so this is not as critical, but APM 2.6 gives more flexibility in that positioning and is a good choice for them,too). This is designed to be used with the Ulbox M8N GPS+Compass Or Ulbox 6M GPS+Compass, so that the GPS/Compass unit can be mounted further from noise sources.
•  APM 2.6 requires a GPS unit and external compass for full autonomy.

Visit Official Wiki For further info

Initial Setup explained here in detail