sensor.py

import RPi.GPIO as GPIO
from datetime import datetime

pin = 18 #Input pin of sensor (GPIO.BOARD)
GPIO.setmode(GPIO.BCM)
GPIO.setup(pin, GPIO.IN)

#Gets binary value
def getBinary():
	#Internal vars
	num1s = 0 #Number of consecutive 1s read
	binary = 1 #The bianry value
	command = [] #The list to store pulse times in
	previousValue = 0 #The last value
	value = GPIO.input(pin) #The current value		
	startTime = datetime.now()
	
	while True:
		#If change detected in value
		if previousValue != value:
			now = datetime.now()
			pulseTime = now - startTime #Calculate the time of pulse
			startTime = now #Reset start time
			command.append((previousValue, pulseTime.microseconds)) #Store recorded data
			
		#Updates consecutive 1s variable
		if value:
			num1s += 1
		else:
			num1s = 0
		
		#Breaks program when the amount of 1s surpasses 10000
		if num1s > 10000:
			break
			
		#Re-reads pin
		previousValue = value
		value = GPIO.input(pin)
		
	#Converts times to binary
	for (typ, tme) in command:
		if typ == 1: #If looking at rest period
			if tme > 1000: #If pulse greater than 1000us
				binary = binary *10 +1 #Must be 1
			else:
				binary *= 10 #Must be 0
			
	if len(str(binary)) > 34: #Sometimes, there is some stray characters
		binary = int(str(binary)[:34])
		
	return binary
	
#Conver value to hex
def convertHex(binaryValue):
	tmpB2 = int(str(binaryValue),2) #Tempary propper base 2
	return hex(tmpB2)