Got Gyro drift? Try Sensor Fusion !

[Richard100]

The posted code was developed with last year's 2013 LabVIEW (LV FRC 2014) and will not work with the new roboRIO until ported. I've had a chance to take a quick look at the LV FRC 2015 copy that we all received, and have noted that the WPI Library for I2C communication has been changed enough to require a bit of tinkering:

(a) The I2C addressing on the WPI I2C open VI now appears to be 7-bit based ... this means you no longer have to left shift the device address by one bit. (Reliable source : Joe Ross / Beachbots, thanx Joe)

(b) The I2C DevRef includes additional parameters to account for things like identifying which of the two roboRIO I2C buses the device is connected to, is now a TypeDef, and re-sequences the parameter order. This make it initially incompatible with my IMU READ Bundle Constants - but is an easy fix.

(c) The code would need to be moved into a project with a roboRIO Target, as the current Project File is cRIO-targeted. Note the I2C VIs change configuration internally as they are target-sensitive ... for example, you'll see the I2C compatibility mode connection on the I2C read VI disappear since I believe roboRIO I2C communication now auto-detects clock stretching.

(d) Also note that the on-line documentation for the I2C read VI appears to have some incorrect information (and is not updated). It claims to limit the maximum number of bytes read in one read operation to four, but I don't think this is correct. This IMU/AHRS code is designed to read six bytes per read operation for efficiency, and the current WPI library still seems to support this.

If you're handy with code tinkering, start with with issues (a)-(c) and you can probably port the code yourself. I will release a roboRIO version myself, on this thread, sometime soon. If anyone already has the IMU sensor and needs to get this working now, let me know so I can help out - I'll re-prioritize my build season to-do list!

Richard