brake.py

 def on_new_messages(self, messages):
      ''' [Optional] Called according to the execution mode of the block.

      Parameters
      ----------
      messages : dict
          A dictionary of the port keys and the values of the incoming messages.

      '''
      bboxes = messages['bboxes'].bboxes #Bounding boxes
      if(self.braked): # check if brake is already applied
          if(time.time() - self.last_time >= self.get_property("time_limt")): # wait x minutes before releasing the brake
              self.braked = False
              print("realeasing the brake")
              msg = Bool()
              msg.data = False
              self.publish("brake_sign", msg)
              self.last_time = time.time()

      else:
          for bbox in bboxes: # cechk every boundig box 
              print("Width: "+str(bbox.width)+" X: "+str(bbox.x))
              if(bbox.width >= self.box_w and bbox.x <= self.box_x_lim): # if the box width > the threshold and in the right location
                  print("Braking")
                  msg = Bool()
                  msg.data = True
                  self.publish("brake_sign", msg)
                  self.braked = True
                  self.last_time = time.time()
                  break