NOTE: compass is NOT included on the 2.6 so that it readily able to use an external compass for increased performance.

The ReadytoFlyer / APM 2.6 is a complete open source autopilot system. It allows the user to turn any fixed, rotary wing or multirotor vehicle (even cars and boats) into a fully autonomous vehicle; capable of performing programmed GPS missions with waypoints. This version comes with the RC/Servo connectors unsoldered, so you can choose between straight or right-angled ones.

GPS not included, But can be added at the bottom on the page. Comes Pre-configured and with GPS/i2c cable now included with combo!

Now with SMD 3.3V regulator MOD! We now are Attaching a 100uF capacitor across the APM’s radio input’s 5V and GND pins will stop the regulator from being blown by plugging in a receiver, with surface mount parts, super clean, no extra wires. You will never know it is there!

There are almost no reports of regulators being blown and no reports of it ever failing in flight. More info here

Features:
• Arduino Compatible
• pre-soldered and tested
• 3-axis gyro, accelerometer, magnetometer and high-performance barometer
• Built in 4 MP Dataflash chip for automatic data logging
• Invensense’s 6 DoF Accelerometer/Gyro MPU-6000
• Measurement Specialties MS5611-01BA03 Barometric pressure sensor.
• Atmel ATMEGA2560 and ATMEGA32U-2 (processing and USB function).
• Micro-US

NOTE:When connecting to USB, do NOT have anything else connected to the board nor Do not connect any devices such as a radio receiver, MinimOSD, GPS, etc while the APM is powered especially while powered only through the USB cable. Doing so could damage the board, this is now minimized with the SMD 3.3V regulator MOD, but best to play it safe and provide the addtional external power, and no connecting anything while powered..

APM 2.6 autopilot airplane system setup wiki: http://plane.ardupilot.com/

APM 2.6 autopilot multicopter system setup wiki : http://copter.ardupilot.com/

APM 2.6 autopilot Car and boats system setup wiki : http://rover.ardupilot.com/

APM 2.6 / ReadytoFlyer endless info. most question you have answered here:

http://www.rcgroups.com/forums/showthread.php?t=1820773

http://www.rcgroups.com/forums/showpost.php?p=23976435&postcount=6

http://www.rcgroups.com/forums/showthread.php?t=1897295#post25070306

http://www.rcgroups.com/forums/showthread.php?t=1899530#post25100936

OLDER WIKI but still some good information and pictures in them

https://code.google.com/p/ardupilot-mega/wiki/APM25board

https://code.google.com/p/ardupilot-mega/wiki/home

APM schematic diagram