Vex Robotics VEXnet Link User manual

ROBOTC
VEXnet Setup Guide • 1
© Carnegie Mellon Robotics Academy / For use with VEX
®
Robotics Systems
Setup
In this document, you will learn how to pair a VEX Cortex Microcontroller to a VEXnet Remote
Control, allowing them to communicate over VEXnet. This document assumes that you have
already updated the master rmware on the VEX Cortex and VEXnet Remote Control.
Establishing a VEXnet Link Setup Guide
VEXnet is an 802.11 WiFi communication system between the VEX Cortex and VEXnet Remote Control.
VEXnet features include:
• Easy to connect (No IP addresses, MAC addresses, passwords, or special security modes)
• Multiple layers of security built-in and always on
• No wireless access point needed; each VEXnet pair makes its own private network
• Hundreds of robots can operate at once; every VEXnet robot has a hidden unique ID
• Optional tether for wired communication
• Optional 9V battery backup to maintain wireless link during a main 7.2V power loss
• LED scheme displays the status of the Robot, VEXnet link, and Game (Competition Mode)
1. Begin by connecting both the Cortex and VEXnet Remote Control to charged batteries.
1a. Connect a Battery to the Cortex
Connect a 7.2V robot battery to the Cortex,
but do not power it ON.
1b. Install Batteries in the VEXnet Remote Control
Remove the battery cover plate on the remote
control. Install 6 AAA batteries, and replace the
battery cover plate. Do not power the remote
control ON.

ROBOTC
VEXnet Setup Guide • 2
© Carnegie Mellon Robotics Academy / For use with VEX
®
Robotics Systems
Setup
Establishing a VEXnet Link Setup Guide (cont.)
2. Tether the USB port on the VEXnet Remote Control to the USB port on the Cortex using
a USB A-to-A cable.
3. Power the Cortex ON. After a few seconds, ROBOT and VEXnet LEDs will blink green,
indicating that the Cortex and VEXnet Remote Control have successfully paired.
2a. VEXnet Remote Control USB Port
Plug one end of the USB A-to-A cable into
the USB port on the VEXnet Remote Control.
2b. VEX Cortex USB Port
Plug the other end of the USB A-to-A cable
into the USB port on the VEX Cortex.
3a. Turn the Cortex ON
3b. Status LEDs
The ROBOT and VEXnet LEDs will blink
green once the Cortex and VEXnet
Remote Control have successfully paired.

ROBOTC
VEXnet Setup Guide • 3
© Carnegie Mellon Robotics Academy / For use with VEX
®
Robotics Systems
Setup
4. Turn the Cortex OFF.
5. Remove the USB A-to-A cable from the VEXnet Remote Control and Cortex.
6. Insert VEXnet USB Keys into both the VEXnet Remote Control and Cortex.
6. VEXnet USB Keys
Insert VEXnet USB Keys into the
VEXnet Remote Control and Cortex.
Establishing a VEXnet Link Setup Guide (cont.)
It does not matter which VEXnet USB
Key you insert into the Cortex versus
the VEXnet Remote Control. Pairing
the Cortex and VEXnet Remote Control
establishes the link; the VEXnet USB Keys
act as antennas for the link.
Note:

ROBOTC
VEXnet Setup Guide • 4
© Carnegie Mellon Robotics Academy / For use with VEX
®
Robotics Systems
Setup
7. Power the Cortex and Remote Control ON. After roughly 15 seconds, the ROBOT and VEXnet
LED’s will blink green, indicating that the VEXnet communication link has been established.
7b. Turn the VEXnet Remote Control ON
7a. Turn the Cortex ON
7c. Status LEDs
After roughly 10 seconds, the ROBOT and
VEXnet status LEDs will start blinking green.
With the VEXnet link established, you should
power OFF your Cortex and VEXnet Remote
Control to preserve battery.
Establishing a VEXnet Link Setup Guide (cont.)

ROBOTC
VEXnet Setup Guide • 5
© Carnegie Mellon Robotics Academy / For use with VEX
®
Robotics Systems
Setup
Issue: Slow blinking green ROBOT light on the Cortex
Solution: Download the Cortex Master Firmware using ROBOTC.
Issue: Slow blinking ROBOT green light on the VEXnet Remote Control
Solution: Push and hold CONFIG button for about 5 seconds, until the status
LEDs starts blinking green. Release it, wait for another 5 seconds, and then turn
the VEXnet Remote Control OFF and then back ON. If that fails, download the
VEXnet Joystick Firmware using ROBOTC.
Issue: Yellow or red ROBOT light on the Cortex
Solution: Make sure you are using fully charged Robot battery.
Issue: Yellow or red ROBOT light on the VEXnet Remote Control, even though
they are both green on the Cortex.
Solution: Power cycle both the VEXnet Remote Control and CORTEX.
Troubleshooting
Establishing a VEXnet Link Setup Guide (cont.)