# This script is in the public domain and has no copyright## This is a simple example script that demonstrates the use of# SimObjects that are not Motes to represent a sensor value. In this# case, it models two "lightbulbs" that move to and from a pair of# motes.#from simcore import *from simutil import *from net.tinyos.sim import *class MovingLight:    def __init__(self, id, x, y, nsteps):        self.obj  = sim.newSimObject(3, x, y)        self.attr = SensorAttribute("light", 7<<7)        self.obj.addAttribute("light", self.attr)        self.obj.addAttributeChangedEvent(self.attr);        d = self.obj.getDistance(20, 55)        step = d / nsteps        def moveTowardsMotes(obj):            objmover.moveTo(obj, id, step, 20, 55, moveBackHome)        def moveBackHome(obj):            objmover.moveTo(obj, id, step, x, y, moveTowardsMotes)        moveTowardsMotes(self.obj)sim.exec("apps/SenseToLeds/build/pc/main.exe", 2, "-b=1 -l=1.0")myModel = LinearSensorModel(10.0, 100.0)sensor.addModel("mymodel", myModel)sensor.addField("light", 1, "mymodel")motes[0].moveTo(20, 50)motes[1].moveTo(20, 60)lights = {}lights[0] = MovingLight(0, 80, 70, 10)lights[1] = MovingLight(1, 80, 30, 20)sim.resume()