Navx2-MXP and ADXR450 Gyro on same RoboRIO / robot

[Dr.G]

Hi,

Issue 1:

We have a NAVX2 and are considering using it mounted on the RoboRIO. What is uncertain is whether this may coexist with the ADXR450 FRC Gyro also plugged directly into the RoboRIO. One could be a useful check on the other. Are there conflicting port issues when considering this? I see that there is a jumper on the ADXR450 (CS0, CS1, CS2). We would want to use the Navx2 with the recommended new AHRS(SPI.Port.kMXP) constructor. The ADXR450 gyro has a similar constructor also with an SPI port parameter, ADXRS450_Gyro​(SPI.Port port).

How could a port conflict be prevented? Should the port be set on the ADXR450 gyro? Or, should the other constructor be used, ADXRS450_Gyro(), that uses CS0? If the latter, should the jumper be left as-is on the ADXRS450 or… ?

Thanks folks. This is our first foray into gyros and navigation.

Issue 2:

I noticed that, in the Swerve drive code provided by REV, the sensor is an ADIS16470. It looks to me that this sensor is compatible with the NavX2, the function calls are the same for getRate(), getAngle() and reset() but the documentation is unclear whether the direction of rate and angle are counter-clockwise on one and clockwise on the other. Would the calls to these methods yield identical results?

[Thad_House]

The SPI on the MXP port is separate from the SPI port the ADXR450 hooks up to, at least for those 2 specific devices. So you’d be fine.

I do believe the direction is opposite between the ADIS and the NavX. But its pretty easy to solve for that, by just negating the output.

[Dr.G]

Thanks for the very quick response, much appreciated. I just wanted to verify whether the ADXRS450 reports angles for rate and angle as clockwise or counter-clockwise. I suspect I know the answer but would like to verify as we start to code subsystems for both the NAVX2 and ADXRS450.

[Technologyman00]

From the spec sheet I’m guessing clockwise is positive

[aopalka]

Dumb question here , but something to think about . ADXR450s only do 2 axises . How are you mounting your rio ? Horizontal or Vertical ? If vertical you would need to figure out what happens in that instance.