import sensor, image
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA) 
sensor.skip_frames(30)
sensor.set_auto_gain(False)
while(True):  
   img = sensor.snapshot()  
   img.lens_corr(1.8)  
   blobs = img.find_qrcodes()   
   if blobs:             
     for b in blobs:                          
      img.draw_rectangle(b[0:4])                          
      img.draw_cross(b[5], b[6],size=5,color=(0,0,0))            
      sensor.snapshot().save("example.jpg")                   
     for code in img.find_qrcodes():             
      print(code)