If the LED's are blinking, you might have the limit switch settings configured wrong or the PWM connection is not hooked up correctly. You should check the cable orientation and read the
manual to match the blink code to the operating state of your Spark. It will also tell you how to make sure the limit switch configuration is correct in the manual. Other than the issue with the
isOpen variable, your code looks correct. (Keeping in mind I'm not familiar with Java wpilib stuff)
