Vex CORTEX Quick Start Manual page 9

7. 2-Wire Motor Port outputs:
a. Motor Port 1 and Motor Port 10.
b. Maximum motor stall current: 3.0 amps at 8.5 volts.
c. Motor chop rate: determined by the compiler. Default code chop rate: 1 kHz.
d. Overcurrent protection: Motor Port 1 through Motor Port 5 shares one 4 amp circuit breaker. Motor Port 6 through
Motor Port 10 shares a second 4 amp circuit breaker.
8. 3-Wire Motor Port outputs:
a. Motor Ports 2 through 9.
b. Maximum motor stall current: internally limited by motor assembly.
c. Motor PWM output: determined by the compiler. Default is 1 to 2 milliseconds high time and a 17 millisecond period.
d. Overcurrent protection: Motor Port 1 through Motor Port 5 shares one 4 amp circuit breaker. Motor Port 6 through
Motor Port 10 shares a second 4 amp circuit breaker.
9. UART Connections: Ground, Power (+5v), RX data in, TX data out. Data rate, byte width, (transmit) stop bits, parity,
etc. are determined by the compiler.
a. Default for LCD data: 19,200 baud, 8 data bits, 1 stop bit, no parity and no flow control.
10. I2C Connections: Ground, Power (+5v), Clock, Data. Data rate, byte width, (transmit) stop bits, parity, etc. are
determined by the compiler.
a. The factory default Hex file does not support I2C.
11. Joystick Calibration (optional): Refer to the VEX Wiki (http://www.vexforum.com/wiki/index.php/VEXnet_Joystick).
12. Debugging:
a. Slow blinking green Robot light on CORTEX.
Solution: Try VEXnet Upgrade Utility. If Master Code 4 or earlier, call or e-mail in to VEX Robotics.
b. Slow blinking Robot green light on Joystick.
Solution: Push and hold config button about 5 seconds until light starts flashing green. Release, wait about 5 seconds,
then turn Joystick OFF and then back ON.
c, Yellow or Red Robot light on the CORTEX. Solution: used fully charged Robot battery.
d. Yellow or Red Robot light on the Joystick, even though the CORTEX is green. Solution: Joystick latches CORTEX's
lowest battery level. Power cycle both Joystick and CORTEX.
e. Fast red blinking Robot light when plugged in to a competition field. Solution: Use a fully charged 9v back-up battery
plugged in to the CORTEX.
f. Robot does not shut off when turned OFF. Solution: At the end of the match, remove the Ethernet cable from the
Competition Port of the Joystick. The CORTEX and Joystick will change to non-competition mode. Power off the
Joystick and CORTEX. The CORTEX will shut off in about 5 seconds.
g. Robot does not do what you want it to do. Solution: Download the default code and test to isolate hardware problems.
Then make small program changes testing after each change.
h. Robot still does not link up, even after tethering. Solution: Debug using a friends system to narrow down the problem,
check the VEX Forum or contact VEX Robotics for assistance.
Page 9 of 9
CORTEX Microcontroller and Joystick Quick Start Guide