Features: APM2.6 flight controller board: Arduino Compatible; Allow connectors to come from the side rather than the top; Includes 3-axis gyro accelerometer and magnetometer along with a high-performance barometer; On-board 4 MegaByte Dataflash chip for automatic datalogging; One of the first open source autopilot systems to use Invensense's 6 DoF Accelerometer/Gyro MPU-6000; Barometric pressure sensor upgraded to MS5611-01BA03 from Measurement Specialties. Atmel's ATMEGA2560 and ATMEGA32U-2 chips for processing and USB functions respectively. GPS module: Adopts Ublox NEO-6M chip; With data backup battery for power off saving function; Built-in electronic compass; Built-in ceramic antenna ensures strong signal.