Pololu IMU(AHRS) orientation sensor

Seems like an amazing sensor for FRC robots. Any one use a similar sensor or have thoughts on this one?

As part of our off season project, we are trying a GY-85 9DOF sensor with gyro, accelerometer, compass that we got on ebay for $16 with shipping. Same size and has an I2C interface which we have connected to the cRIO via the DSC. You have to do your own math, but you cant beat the price.

If you haven’t already, take a look a the nav6 Open Source IMU designed for FIRST robotics. It implements sophisticated inertial navigation algorithms onboard and is designed for easy integration onto a FRC robot. If there’s any questions, you can email me with any questions directly at [email protected].

We are trying to use the Pololu MinIMU-9 v2 for just the gyro. It is amazing how flexible the device is, which really means there are many ways to mis-configure it. I really appreciate efforts like the navy, because of this.

Once we work out the details, we will post our LabView code.

Autocorrect thinks nav6 should be navy…

Anyway, after much trial and tribulation, we finally got the MinIMU-9 to do what we want. We still need to clean up our code, and put it into a similar architectural form to the WPI library code, but that should be available to all, soon. Specifically, we created code to read the L3G20 gyro on the IMU, so our code will work with all boards that use this gyro component.

For the curious, we tried to leave our outputs in integer form. The gyro outputs two unsigned integer bytes, which get concatenated into a 16 bit integer, which is represented as a signed integer in two’s compliment. Labview sees this concatenated 16-bit integer as unsigned, and casting it to a signed integer type just didn’t work. For some reason, changing this integer output to a floating point type double, immediately after the concatenation, fixed our problems.

We’ve finished our library and have posted it in the LabView section. Our code has been tested on the Pololu MinIMU-9 v2, but there is a list at the link below of the other Pololu and Adafruit boards that it will work with.