iC880A Backplane: LED and button example script

## leds_button.py
import sys
import time
from RPi import GPIO

LED_R = 36
LED_Y = 38
LED_B = 40
BUTTON = 32

# Use the BOARD numbering system
GPIO.setmode(GPIO.BOARD)

# Set up LED pins as output
GPIO.setup(LED_R, GPIO.OUT)
GPIO.setup(LED_Y, GPIO.OUT)
GPIO.setup(LED_B, GPIO.OUT)

# Set up button pin as input with internal pull-up
GPIO.setup(BUTTON, GPIO.IN, pull_up_down=GPIO.PUD_UP)

# Turn on LEDs with 1 second delay
GPIO.output(LED_R, GPIO.HIGH)
time.sleep(1)
GPIO.output(LED_Y, GPIO.HIGH)
time.sleep(1)
GPIO.output(LED_B, GPIO.HIGH)

# Wait for button press
print('Waiting for button press...')
try:
    GPIO.wait_for_edge(BUTTON, GPIO.FALLING)
except KeyboardInterrupt:
    print('Aborted.')
    pass

# Turn off LEDs again with 1 second delay
GPIO.output(LED_R, GPIO.LOW)
time.sleep(1)
GPIO.output(LED_Y, GPIO.LOW)
time.sleep(1)
GPIO.output(LED_B, GPIO.LOW)

# Clean up
GPIO.cleanup()