#!/usr/bin/env python

"""
   Demonstration of GPIO access under Python for Bifferboard
   modified by Sunspot to control lines 0 and 1
   place in /usr/sbin 755
   (www.bifferos.com) (www.sunspot.co.uk)

"""

import os, fcntl, struct, time, sys


class GPIO:
  "Class to encapsulate communication with the driver"

  def __init__(self):
    self.fd = os.open("/dev/gpio_proxy", os.O_RDWR)

  def gpio_set_value(self, pin, val):
    if val:
      fcntl.ioctl(self.fd, 1, pin)
    else:
      fcntl.ioctl(self.fd, 2, pin)

  def gpio_direction_output(self, pin, val):
    if val:
      fcntl.ioctl(self.fd, 3, pin)
    else:
      fcntl.ioctl(self.fd, 4, pin)

  def status(self):
    fcntl.ioctl(self.fd, 5, 0)

  def gpio_direction_input(self, pin):
    fcntl.ioctl(self.fd, 6, pin)

  def gpio_get_value(self, pin):
    return fcntl.ioctl(self.fd, 7, pin)



def flash1(g):
  g.gpio_direction_output(1,1)

  # Print the status of the GPIO register
  g.status()

  # Flash the red LED on and off ten times.
  for i in xrange(0,3):
    g.gpio_set_value(1,1)
    time.sleep(0.5)
    g.gpio_set_value(1,0)
    time.sleep(0.5)
		

def flash0(g):
  g.gpio_direction_output(0,1)

  # Print the status of the GPIO register
  g.status()

  # Flash the red Green on and off ten times.
  for i in xrange(0,3):
    g.gpio_set_value(0,1)
    time.sleep(0.5)
    g.gpio_set_value(0,0)
    time.sleep(0.5)	
    
def flash5(g):
  g.gpio_direction_output(5,1)

  # Print the status of the GPIO register
  g.status()

  # Flash the red Green on and off ten times.
  for i in xrange(0,3):
    g.gpio_set_value(5,1)
    time.sleep(0.5)
    g.gpio_set_value(5,0)
    time.sleep(0.5)	    
		
def led0_on(g):
  g.gpio_direction_output(0,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led on
  print "The green LED 0 in ON"
  g.gpio_set_value(0,1)
			
def led0_off(g):
  g.gpio_direction_output(0,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led off
  print "The green LED 0 is OFF"
  g.gpio_set_value(0,0)


def led1_on(g):
  g.gpio_direction_output(1,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led on
  print "The red LED 1 is ON"
  g.gpio_set_value(1,1)
			
def led1_off(g):
  g.gpio_direction_output(1,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led off
  print "The red LED 1 is OFF"
  g.gpio_set_value(1,0)
		
def led5_on(g):
  g.gpio_direction_output(5,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led on
  print "The red LED 5 is OFF"
  g.gpio_set_value(5,1)
			
def led5_off(g):
  g.gpio_direction_output(5,1)
  # Print the status of the GPIO register
  g.status()
  # Turn the green led off
  print "The red LED 5 is ON"
  g.gpio_set_value(5,0)
		
def button(g):
  # Sample the button status
  # You must set the value of an input pin to '1' before using it as input
  g.gpio_set_value(4,1)
  g.gpio_direction_input(4)
  button = g.gpio_get_value(4)
  print "Button is now", button

    
def Usage():
  print "led_control.py - Control the green and red leds on gpio 0 and 1"
  print 
  print "usage: led_control.py <operation>"
  print
  print "<operation> can be:"
  print "'flash0': Flash the green LED 0 on and off"
  print "'flash1': Flash the red LED 1 on and off"  
  print "'button': Sample the button state"
  print "'led0_on or led0_off': Switch the green led 0"
  print "'led1_on or led1_off': Switch the red led 1"
  print "'led5_on or led5_off': Switch the surface mount red led 5"  
  print


if __name__ == "__main__":

  if sys.argv[1:]:
    cmd = sys.argv[1]
    if cmd == "flash1":
      flash1(GPIO())
    elif cmd == "flash0":
      flash0(GPIO())
    elif cmd == "flash5":
      flash5(GPIO())      
    elif cmd == "led0_on":
      led0_on(GPIO())
    elif cmd == "led0_off":
      led0_off(GPIO())
    elif cmd == "led1_on":
      led1_on(GPIO())
    elif cmd == "led1_off":
      led1_off(GPIO()) 
    elif cmd == "led5_on":
      led5_on(GPIO())
    elif cmd == "led5_off":
      led5_off(GPIO()) 
            
    elif cmd == "button":
      button(GPIO())
    else:
      Usage()
  else:
    Usage()