import RPi.GPIO as GPIO
   import time
   import paho.mqtt.client as mqtt

   GPIO.setmode(GPIO.BOARD)
   
   GPIO.setup(13,GPIO.IN)
   
   mqttc=mqtt.Client()
   mqttc.connect("iot.eclipse.org",1883,60)
   mqttc.loop_start()
   
   def reading1():
     a=GPIO.input(13)
     print(a)
     return a

   while 1:
     result,mid)=mqttc.publish("paho/temp_ab",t,2)
     time.sleep(1)

   mqttc.loop_stop()
   mqttc.disconnect()