def callback(data):
    global avoidingVehicle
    rospy.loginfo((rospy.get_caller_id() + ' Led control String received: %s'), data.data)
    if (data.data == 'stop'):
        turnOffMotors()
    elif ((data.data == 'front') and (avoidingVehicle == False)):
        avoidingVehicle = True
        avoidVehicle()
    elif (data.data == 'w'):
        setSpeed(150, 150)
    elif (data.data == 's'):
        turnOffMotors()
def callback(data):
    global avoidingVehicle
    rospy.loginfo((rospy.get_caller_id() + ' Led control String received: %s'), data.data)
    if (data.data == 'stop'):
        turnOffMotors()
    elif ((data.data == 'front') and (avoidingVehicle == False)):
        avoidingVehicle = True
        avoidVehicle()
    elif (data.data == 'w'):
        setSpeed(150, 150)
    elif (data.data == 's'):
        turnOffMotors()