"""
switch.py
=========

Light up some leds when the USR switch on the pyboard is pressed.

Example Usage::

 Micro Python v1.0.1 on 2014年05月12日; PYBv1.0 with STM32F405RG
 Type "help()" for more information.
 >>> import switch
 >>> switch.run_loop()
 Loop started.
 Press Ctrl+C to break out of the loop.

"""

import pyb

switch = pyb.Switch()
red_led = pyb.LED(1)
green_led = pyb.LED(2)
orange_led = pyb.LED(3)
blue_led = pyb.LED(4)
all_leds = (red_led, green_led, orange_led, blue_led)

def run_loop(leds=all_leds):
 """
 Start the loop.

 :param `leds`: Which LEDs to light up upon switch press.
 :type `leds`: sequence of LED objects
 """
 print('Loop started.\nPress Ctrl+C to break out of the loop.')
 while 1:
 try:
 if switch():
 [led.on() for led in leds]
 else:
 [led.off() for led in leds]
 except OSError: # VCPInterrupt # Ctrl+C in interpreter mode.
 break

if __name__ == '__main__':
 run_loop()