def pump_run(self, pump_port, switch):    
     '''block the UI to avoid "segmentation fault"'''
     print "activating pump", pump_port 			
     Gdk.threads_enter() # needed to avoid Segmentation fault error
     switch.set_active(True)
     Gdk.threads_leave() # needed to avoid Segmentation fault error
     
     '''run the pump'''
     pumps.control_pumps(pump_port,self.pump_length)
 
     '''block the UI again to avoid "segmentation fault"'''	
     Gdk.threads_enter() # needed to avoid Segmentation fault error
     print "deactivating pump", pump_port
     print "" 			
     switch.set_active(False)
     Gdk.threads_leave() # needed to avoid Segmentation fault error
     return
 def on_PUMP2_BUTTON_clicked(self, data=None):
     print "pump2 is activating for ", self.pump_length, " seconds"
     pumps.control_pumps(self.port_pump2,self.pump_length)
     return