import RPi.GPIO as GPIO
import time
import explorerhat

GPIO.setmode(GPIO.BCM)

TRIG = 31
ECHO = 23

print "Distance Measurement In Progress"

GPIO.setup(TRIG,GPIO.OUT)
GPIO.setup(ECHO,GPIO.IN)

GPIO.output(TRIG, False)
print "Waiting For Sensor To Settle"
time.sleep(1)

while True:
    GPIO.output(TRIG, True)
    time.sleep(0.00001)
    GPIO.output(TRIG, False)

    while GPIO.input(ECHO)==0:
      pulse_start = time.time()

    while GPIO.input(ECHO)==1:
      pulse_end = time.time()

    pulse_duration = pulse_end - pulse_start

    distance = pulse_duration * 17150

    distance = round(distance, 2)

    if distance < 10:
        explorerhat.light.off()
        explorerhat.light[0].on()
        explorerhat.light[1].on()
        explorerhat.light[2].on()
        explorerhat.light[3].on()
    elif distance < 20:
        explorerhat.light.off()
        explorerhat.light[0].on()
        explorerhat.light[1].on()
        explorerhat.light[2].on()
    elif distance < 30:
        explorerhat.light.off()
        explorerhat.light[0].on()
        explorerhat.light[1].on()
    elif distance < 40:
        explorerhat.light.off()
        explorerhat.light[0].on()
    else:
        explorerhat.light.off()

    print "Distance:",distance,"cm"

    time.sleep(1)



GPIO.cleanup()