Read distance information from SICK sensor
##Sources
用http://wiki.ros.org/rosserial_arduino/Tutorials/Hello%20World里的代码，注意波特率和数据类型就好
##Solving "Permission Denied"
$ sudo usermod -a -G dialout <username>
$ sudo chmod a+rw /dev/ttyACM0
##Booting
- roscore
- rosrun rosserial_python serial_node.py /dev/ttyUSB0
- rostopic echo SICK_sensor
- Then we can use rosbag to record data, rqt to plot