FTC Installation

navX2-MXP can be easily used with the FTC Android-Based Robot Control System.   Both power to and signaling to/from the navX2-MXP occurs via the I2C interface by way of either a Expansion Hub or a Control Hub from REV Robotics.

Electrical Wiring Instructions

  • Select one of the 4 I2C ports on the Hub, as shown above.  Note that the ports are numbered from 0.
  • Using a I2C to JST PH Cable, connect the +5V, Data (SDA), Clock (SCL) and GND pins to the corresponding pins on the navX2-MXP External I2C Port Connector.

NOTE:  The I2C to JST PH Cabled linked-to above has a different pin out on the .1″ (“Molex”) black plastic header-side than found on the navX2-MXP connector shown below.  Therefore you may need to re-order the pins on this end of the connector to correctly match the navX2-MXP pinout, by carefully removing and re-inserting the wire leads into the connector..

  • Connect the Power (+), Data (SDA), Clock (SCL) and GND pins to the corresponding pins on the navX2-MXP External I2C Port Connector.

navx_mxp_external_i2c_port_closeup

NOTE:  Although the navX2-MXP is typically powered via 5VDC when used with the RoboRIO, navX2-MXP is fully 3.3V compatible, and thus may be powered via the Expansion or Control Hub.

Electrical Wiring Verification

If properly wired, when power is applied to the Expansion or Control Hub, the Red 3.3V LED on the navX2-MXP should light up.
If trouble occurs communication with the navX2-MXP, double-check that the SDA and the SCL wires on the Expansion Control Hub match the corresponding pins on the navX2-MXP.

Physical Installation on the Robot

The navX2-MXP circuit board should be mounted such that it is firmly attached to the robot chassis. The quality of this mounting will be directly reflected in the quality of navX2-MXP inertial measurements. To ensure quality, carefully follow these guidelines:

  • Whereever the navX2-MXP circuit board is placed, it should be tightly mounted; it should be a part of the chassis mass, and should move exactly as the chassis moves. Avoid mounting the navX2-MXP circuit board in an area of the chassis that might be flexible, as this could introduce vibration to the inertial sensors that does not represent the chassis inertial properties.
  • The navX2-MXP circuit board should be mounted in the center of the chassis, which ensures the origin of the yaw/pitch/roll axes truly represent the chassis center.
  • Be sure to understand the orientation of the navX2-MXP circuit board, relative to the chassis, and decide whether OmniMount is needed.
  • Housing the navX2-MXP circuit board in some form of protective enclosure is highly recommended, to protect it from damage. This should both protect the circuit board from damage, and provide strain relief for the cables that connect to the navX2-MXP circuit board.