The VEX ARM® Cortex®-based Microcontroller coordinates the flow of all information and power on the robot. It has built in bi-directional communication for wireless driving, debugging and downloading using the VEXnet wireless link. The Microcontroller is the brain of every VEX robot.

Programming easyC V4
ROBOTC for VEX Robotics v4.x
Size 4.5in W x 3.9in L x 1in H
  • 0.302 lbs (137 grams)

Click here for more specific and important information about the Cortex Microcontroller

Built-in VEXnet Technology: Wireless driving, wireless debugging, and wireless downloading. Compatible with either the first generation VEXnet USB Key or the new VEXnet Key 2.0.

Motor Ports: (8) standard 3-wire Motor or Servo ports. (2) 2-wire Motor ports.

I2C Smart Sensor Port: Will connect to multiple n

ew smart sensors in the future.

UART Fast Serial Ports: Connects to the VEX LCD Display (19,200 baud) and will have future support to 1.125 Mbaud

Digital/Analog Input Ports: (8) high-res Analog Inputs, (12) fast Digital I/Os that can be used as interrupts.

Rx1 and Rx2 Ports: Also support for two 75MHz crystal transmitters and receivers

Battery Ports: Connect 7.2V power sources, such as the Battery Holder or the VEX 7.2V Robot Battery. Also connect a 9V Backup Battery to protect against communication losses.


The VEXnet Joystick allows a human operator to control a robot in real-time using the VEXnet wireless link. The joystick has two 2-axis analog joysticks, 4 trigger buttons and two 4-button directional pads. It also has an accelerometer that provides X-Y tilt outputs. This allows you to control an arm or drive system by changing the orientation of the joystick (tilting). Just plug a VEXnet USB Adapter Key or new VEXnet Key 2.0 into the port on the back and enjoy the ultimate in robot control.

Downloads & Docs Documentation
VEX ARM® Cortex®-based Microcontroller / VEXnet Joystick User Guide
Bootloader & Firmware Change Log
VEX Robot Troubleshooting Flow Charts
Compatibility VEXnet USB Adapter Key or VEXnet Key 2.0 (not included)
Can only be used with the VEX ARM® Cortex®-based Microcontroller.
Radio Frequency Meets all 802.11b/g specifications (when using the first generation VEXnet USB Adapter Key)
User Inputs
  • (2) X-Y Analog Joysticks
  • (8) Top Buttons
  • (4) Back Buttons
  • (1) Accelerometer providing X-Y Tilt outputs
  • (1) Competition Port
  • (1) Partner Port (for connection to another VEXnet Joystick)
  • (1) Program Port (for wireless programming with the VEX ARM® Cortex®-based Microcontroller)
Batteries 6 AAA Batteries (not included)
Size 5.5in W x 4.3in L x 2.2in H



The VEXnet Key 2.0 provides wireless communication between VEX ARM® Cortex®-based Microcontroller and VEXnet Joysticks. This key utilizes the new VEXnet 2.0 communication protocol over a custom 2.4 GHz radio.

  • Works with the VEX ARM® Cortex®-based Microcontroller
  • Uses VEXnet 2.0 communication protocol over 2.4 GHz data radio
  • Rubber fins help retain key once installed
Kit Contents (1) VEXnet Key 2.0
Downloads & Docs CAD File (STEP)
Firmware Update Information
Compatibility Works with the VEX ARM® Cortex®-based Microcontroller.
Only works with another VEXnet Key 2.0 – does not work with a first generation VEXnet USB Adapter Key.
Radio Frequency Custom 2.4 GHz data radio
Ports (1) USB Port