LSM9DS0 9DOF sensor AHRS sketch
Like the original LSM9DS0_simple.ino sketch, it'll demo the following:
- How to create a LSM9DS0 object, using a constructor (global variables section).
- How to use the begin() function of the LSM9DS0 class.
- How to read the gyroscope, accelerometer, and magnetometer using the readGryo(), readAccel(), readMag() functions and the gx, gy, gz, ax, ay, az, mx, my, and mz variables.
- How to calculate actual acceleration, rotation speed, magnetic field strength using the calcAccel(), calcGyro() and calcMag() functions.
- How to get the temperature from the accelerometer and display on the Serial monitor in degrees Centigrade.
In addition, the sketch will demo:
- How to calculate and correct for the accelerometer and gyro biases
- How to check for data updates using interrupts
- How to display output at a rate different from the sensor data update and fusion filter update rates
- How to specify the accelerometer anti-aliasing (low-pass) filter rate
- How to use the data from the LSM9DS0 to fuse the sensor data into a quaternion representation of the sensor frame orientation relative to a fixed Earth frame providing absolute orientation information for subsequent use.
- An example of how to use the quaternion data to generate standard aircraft orientation data in the form of Tait-Bryan angles representing the sensor yaw, pitch, and roll angles suitable for any vehicle stablization control application.
I added a sketch specifically for the LSM9DS0 Mini and Micro-Add-On shields. It uses a Teensy 3.1-specific i2c Wire library called i2c_t3.h, which allows easy access to Teensy-specific capabilities such as specification of which set of hardware i2c pins will be used, the bus speed (up to 1 MHz!) and also allows master and/or slave designation to handle multiplexing between i2c devices. See www.pjrc.com/teensy and http://forum.pjrc.com/threads/21680-New-I2C-library-for-Teensy3 for details.
A description of the modular Teensy Project which uses the LSM9DS0 motion sensor, among others, is described here.
For a discussion of the relative merits of modern board-mounted pressure sensors, see here.