Check out the Robot Feedback LED's on the Operator Interface. You can use these to signal your drivers that the robot is aligned (and no one on the other alliance has to know!).
You can use the RC to turn the Robot Feedback LED's on the OI on or off. The variables are already defined in the default MPLAB code. The variable names correspond to the descriptive labels printed on the Operator Interface:
OI Port 1 LED Output Variables:
Pwm1_green (Code: Pwm1_green = 1; //turns on the LED. 0 to turn off.)
Pwm1_red
Pwm2_green
Pwm2_red
OI Port 3 LED Output Variables:
Relay1_green
Relay1_red
Relay2_green
Relay2_red
If you want to, you can build your own LED lights into a custom button box (
example) and wire the LED's to LED output pins on OI Ports 1 and 3. These outputs will be controlled by the same custom RC code that turns the OI's Feedback LED's on and off. Check out the OI Reference Guide on ifirobotics.com for more information on how to do this:
http://www.ifirobotics.com/oi.shtml
http://www.ifirobotics.com/docs/oi-r...e-11-21-05.pdf
We always go to Radio Shack and buy the LED modules with built-in resistors for use on our team's button box. They always work out well. Red wire to desired LED output; black wire to any available Ground pin.