#!/usr/bin/python
# -*- coding:utf-8 -*-
import RPi.GPIO as GPIO
import time
 
Clock = 16
Address = 20
DataOut = 21
DOUT = 17
 
 
def ADC_Read(channel):
 value = 0;
 for i in range(0,4):
 if((channel  (3 - i)) & 0x01):
  GPIO.output(Address,GPIO.HIGH)
 else:
  GPIO.output(Address,GPIO.LOW)
 GPIO.output(Clock,GPIO.HIGH)
 GPIO.output(Clock,GPIO.LOW)
 for i in range(0,6):
 GPIO.output(Clock,GPIO.HIGH)
 GPIO.output(Clock,GPIO.LOW)
 time.sleep(0.001)
 for i in range(0,10):
 GPIO.output(Clock,GPIO.HIGH)
 value <<= 1
 if(GPIO.input(DataOut)):
  value |= 0x01
 GPIO.output(Clock,GPIO.LOW)
 return value
 
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(Clock,GPIO.OUT)
GPIO.setup(Address,GPIO.OUT)
GPIO.setup(DataOut,GPIO.IN,GPIO.PUD_UP)
GPIO.setup(DOUT,GPIO.IN)
 
lastdata = 2
try:
 while True:
 data = GPIO.input(DOUT)
 if lastdata and (lastdata == 1):
  continue
 if data == 0:
  print 'Near the Obstacles'
  print 'AD: %d ' % ADC_Read(6)
 if data == 1:
  print 'Far the Obstacles'
 lastdata = data
 time.sleep(0.1)
except:
 GPIO.cleanup()