[kevin.li.rit]

a limit switch is pretty simple. You plug it into the digital inputs and look for it to be pressed, when it is pressed it creates a 0 signal.

if(!rc_dig_in07)// if limit switch is pressed
{ pwm05=127;//Stop arm!
backuparm(); //use a function here to back up the arm so it no longer hits the limit switch.
}

There Many ways to use a limit switch...