align.py

#####################################SETUP####################################### 

# Standard setup starts
import RPi.GPIO as GPIO, time, os
GPIO.setmode(GPIO.BCM)
GPIO.setup(23, GPIO.IN)



# Standard setup ends

def RCtime (RCpin): ## Setup LDR detection
        reading = 0
        GPIO.setup(RCpin, GPIO.OUT)
        GPIO.output(RCpin, GPIO.LOW)
        time.sleep(0.05)
 
        GPIO.setup(RCpin, GPIO.IN)
        # This takes about 1 millisecond per loop cycle
        while (GPIO.input(RCpin) == GPIO.LOW):
                reading += 1
        return reading
        
# define function flashing LED - flash rate defined in the call
def flashled( str ):
    GPIO.setup(22, GPIO.OUT) ##Setup LED
    GPIO.output(22, True)
    time.sleep(str)
    GPIO.output(22, False)
    time.sleep(str)
    
    # define function playing sound - file defined in call
def playsound( str ):
    bashCommand = str
    import subprocess
    process = subprocess.Popen(bashCommand.split(), stdout=subprocess.PIPE)
    output = process.communicate()[0]
   
# define function
def laseron():
    GPIO.setup(17, GPIO.OUT) ##Setup Laser
    GPIO.output(17, True) ## Laser on
   
   # define function
def laseroff():
    GPIO.setup(17, GPIO.OUT) ##Setup Laser
    GPIO.output(17, False) ## Laser on

def checker():


	 ## this quickly pulses the laser and checks if a signal is recieved if not recieved triggers setup.

	laseron(); # turn laser on pin #17
    
    # delare variable
 
	if (RCtime(18) < 1001): ## signal detected STANDBY MODE
        	laseroff() # turn laser off
        	print "aligned"
        	print (RCtime(18)
        	laseroff();
                    
                
	elif (RCtime(18) >1000):## no signal ALIGN LASER
        	print "not aligned"
        	print (RCtime(18)
    		#AlignLaser() ## calls align laser function (at the top)
    		laseroff();
  		laseroff();


checker()