FTC Installation

Note:  navX-MXP firmware version 2.2 or higher is required to use navX-MXP w/the FTC Android-Based Robot Control System.

navX-MXP can be used with the FTC Android-Based Robot Control System released in 2015.   Both power to and signaling to/from navX-MXP occurs via the I2C interface by way of the Core Device Interface Module (DIM) from Modern Robotics, Inc, as shown in the below diagram:

navx_mxp_dim_connection

Electrical Wiring Instructions

  • Select one of the 6 I2C ports on the DIM, as shown below.  Note that the ports are numbered from 0, starting at the bottom-most port on the left-hand side of the DIM.
DIM_I2C_Port_Detail
  • Connect the +5V, Data (SDA), Clock (SCL) and GND pins on the selected DIM I2C port to the corresponding pins on the navX-MXP External I2C Port Connector.

navx_mxp_external_i2c_port_closeup

  • To ensure the +5V from the DIM is used to power the navX-MXP board circuitry, ensure that the “Voltage Select” jumper is set to 5V.
navx_mxp_voltage_select_closeup

Electrical Wiring Verification

If properly wired, when power is applied to the DIM, the Red 3.3V LED on the navX-MXP should light up.
Double-check that the SDA and the SCL wires on the DIM match the corresponding pins on the navX-MXP circuit board.

Physical Installation on the Robot

The navX-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 navX-MXP inertial measurements. To ensure quality, carefully follow these guidelines:

  • Whereever the navX-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 navX-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 navX-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 navX-MXP circuit board, relative to the chassis, and decide whether OmniMount is needed.
  • Housing the navX-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 navX-MXP circuit board.