Cortex Microcontroller and VEXnet Joystick User Guide
Page 4 of 14
f. A valid link is shown below. The VEXnet LED will be blinking fast green on both the Cortex and Joystick. The VEXnet
light is the only LED that determines a valid link. It usually takes 5 to 10 seconds to successfully establish a link. Once
the units are linked, the Robot and Joystick LED Indicators will show the battery levels in their respective unit. A
green Robot or Joystick LED indicates that their respective batteries are fully charged batteries. As the battery levels
decrease, these LEDs will change to yellow and then red.
g. If the units fail to establish the VEXnet link after 30 seconds, turn them both OFF and then back ON. If they still fail
to link up, refer to the Troubleshooting Flowchart in section 7.
3. Basic Configuration
A few examples of the Default Code that is preloaded onto the Cortex Microcontroller are shown below. For complete
details on the Default Code, refer to Section 4.
Please note: The default code for the Cortex Microcontroller varies
from that of the PIC Microcontroller. Please review and follow the tables in this document to ensure your robot
behaves in the manner you wish.
a. Add motors and test. The following picture shows two VEX 3-Wire Motors plugged into Motor Port 2 and Motor
Port 5. With the Default Code, pushing Joystick Channel 3 up will cause Motor 2 to turn clockwise. Pushing Joystick
Channel 2 up will cause Motor 5 to turn counterclockwise.
b. Motor Reversing: The Default Code allows jumpers or switches to be installed in the Digital Ports to invert the motor
direction. This is useful to correct the direction of motors without changing code, or when using a switch to reverse a
motor if the robot hits an object. The following picture shows motor reversing jumpers installed in Digital Ports 2 and
5 to reverse Motor Ports 2 and 5. If you are using 2-wire motors, another way to invert the motor’s direction is to
reverse the motor’s connection where it is plugged into a Motor Controller 29 Module or Motor Ports 1 or 10 on the
Cortex.
