Quote:
Originally Posted by dougwilliams
Scott and All,
I was wondering if there's a good layman's comparison of the nav features comparing the Nav6 vs the NavX?
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What benefit is the NavX providing over the Nav6? Practically speaking for an FRC robot? Does the 9-axis benefit most users? Are there other nav features I may not be considering, or future products worth waiting for? We typically were just using yaw readings for FOD - but may expand that to some of the accel features in the off season and next year.
Thanks for the help -
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The nav6 is fine for FOD (Field-Centric Drive), rotate to angle and "Straight Strafing". The navX MXP provides a simplified mounting solution, and integrated I/O Expansion.
The navX MXP also provides I2C/SPI interfaces and a USB interface - which are faster than the RS-232 interface of the nav6. But many teams use the serial interface successfully.
As you note, the navX MXP also provides 9-axis features, but these are not required for FOD; and indeed, they require more effort to calibrate and are sensitive to magnetic disturbances. The 9-axis heading does give an "absolute" heading, but the 6-axis yaw is simpler to use. There are certain applications where measuring the compass heading at the beginning of a match (before the motors are turned on) can allow the robot software to figure out where "zero degrees" on the field is at the beginning of a match, but it's an individual decision as to whether this is worth the effort to perform magnetometer calibration.
The navX MXP will be where future firmware development efforts are focused, since the navX MXP has a much more capable processor. Moving ahead, we plan to develop a features that only the navX MXP will have: (a) vertical mounting for the navX MXP, and (b) improving the navX MXP Linear Acceleration measures to be more useful for velocity/displacement calculations. Existing navX MXP customers will be able to upgrade to these at no charge w/a firmware upgrade.