WorldViz User Forum - using sensor data in Physics1.py

I'm trying to change the code of physics1.py and use sensor data to control a ball to bump into other objects. Please see the following code. The yellow ball linked with sensor behaves erratically, though the printed sensor data seems okay. I wonder whether that because I try to link a dynamic object to a sensor. Is it possible to "turn off" the dynamics on this ball (e.g. gravity) while keep its collision response (I mean, when it collides with other objects, it will push them out of the way with seemingly infinite force)?

Code:

viz.enable(viz.PHYSICS)



#Add the ground

ground = viz.add('tut_ground.wrl')

#This will create an infinite collision plane that points upward with height 0

ground.collideplane(0,1,0,0)



#Declare some constants

NUM_BALLS = 40

BALL_ALPHA = 0.8 #0.5

BALL_RADIUS        = 0.1



#The list of rigid body objects

bodies = []



#Add a ground plane to the physcis simulation

viz.addplane(0,1,0,0)



PORT_MOTIONSTAR = '193.61.166.56' 

sensor1 = viz.add('motionstar.dls')

sensor2 = viz.add('motionstar.dls')



#Add a bunch of balls to the physics simulation

for x in range(0,NUM_BALLS):

        #Add the geometric representation of the ball

        ball = viz.add('ball.wrl')

        #The balls collision will be represented by a sphere with BALL_RADIUS

        ball.collidesphere(BALL_RADIUS)

        #Scale the our ball to match the size of the sphere

        ball.scale(BALL_RADIUS/0.4,BALL_RADIUS/0.4,BALL_RADIUS/0.4)

        #Set the alpha value of the ball

        ball.alpha(BALL_ALPHA)

        #Add the ball to the physical objects list

        bodies.append(ball)



        #Add a box model

        box = viz.add('box10cm.wrl')

        #Use the boxes bounding box for collisions

        box.collidebox()

        #Set the alpha value of the box, transparency

        box.alpha(BALL_ALPHA)

        #Add the box to the list of physical objects

        bodies.append(box)

        

myBall1 = viz.add('ball10cm.wrl')

myBall1.color(viz.YELLOW)

myBall1.collidesphere(BALL_RADIUS)



myBall1.link(sensor1)



#viz.lookat(0,0,0)



#This function will reset the physics simulation

def Reset():

        for x in range(0,NUM_BALLS+1):

                #Reset the physics of the object (This will zero its velocities and forces)

                bodies[x].reset()

                #Translate the object to the proper height 

                bodies[x].translate(vizmat.GetRandom(-2,2),0,vizmat.GetRandom(-2,2))

                #Reset the rotation of the object

                bodies[x].rotate(0,1,0,0)

        

Reset()



def mykey(key):

        #Reset the physics simulation

        if key == 'r':

                Reset()        



def timer(num):

        print sensor1.get()

        

#Create a callback for keyboard events

viz.callback(viz.KEYBOARD_EVENT,mykey)



#Set the background color

viz.clearcolor(0.5,0.5,1)

viz.starttimer(0,0.5,viz.FOREVER)

viz.callback(viz.TIMER_EVENT, timer)

Do I have to the dynamics manually like the duckcourt example?
Any ideas? Thank you.