Adafruit 9dof C++ driver for Raspberry pi support. Contains individual drivers for both the LSM303 and L3GD20 sensors, and a unified driver for the entire IMU.
The CMakeLists.txt file shows how to include the driver in a project. This compiles main.cpp which shows basic usage of the driver. You should be able to easily include this in any cmake project.
The ADAFRUIT_9DOF class inherits from the LSM303 and L3GD20 classes. I am using the MadgwickAHRS algorithm to calculate the orientation of the IMU. To enable communication the IMU simply create an instance of the ADAFRUIT_9DOF class. From here you can read from each individual sensor using the readAccell(), readMag() and readGyro() functions (these all take a pointer to an array of 3 floats floats and will write the processed 3D vector read from sensor to this array). To read all sensors at one time use the readAll() function. This will store the results in the accel, mag and gyro structures in the class. To calculate the orientation use the calcCoord() function. This function takes a pointer to an array of 4 floats and writes the 4D vector quaternion to the array. This is demonstrated in main.cpp.