MPU6000 SPI / MS5611 / HMC5883L Library For Arduino (APM 2.5/APM 2.6)

MPU6000 Arduino Library

http://myquadcopters.blogspot.my/2014/04/quadcopter-5-accelerometer-and-gyro.html

MS5611 Arduino Library

https://github.com/jarzebski/Arduino-MS5611

https://code.google.com/r/mspirit-ardupilot/source/browse/libraries/AP_Baro/AP_Baro_MS5611.cpp?r=ea2cfbb4f8d3a1893597bebf8e5ee3fa2cb242ea

HMC5883L Arduino Library

https://github.com/jarzebski/Arduino-HMC5883L