[Al Skierkiewicz]

Walker,
Robot rules do not allow LEDs to be attached at the output of the speed controllers, sorry. There are other issues that actually make this impractical. The output polarity of the controller changes with direction which would require either two LEDs (one for each polarity) or a bridge rectifier (difficult to do correctly) to allow the LED to respond to either direction. The LEDs will not be visible during normal competition and as others have said, the brightness of the LED will vary depending on the output PWM duty cycle. However, if you are intent on knowing the output of each controller, robot rules have allowed for low impedance current monitoring for many years. Many of the controllers actually provide this info on the CAN buss when you use it. That feedback can be used to control LED drivers through software and legal hardware.