Hokuyo URG-04LX with Arduino Mega

Hi Guys,

I am trying to interface a Lidar (Hokuyo URG-04LX) with Arduino Mega Board. I have tried a lot of things but cannot get the data to show up on the serial port :(

Here is the data sheet: http://www.hokuyo-aut.jp/02sensor/07scanner/download/data/URG-04LX_spec.pdf

The communication used by the Lidar is RS232C so I have put in a RS232 to TTL conversion circuit before connecting the RX and TX lines to the Arduino. But I don't get the right data.

Does anyone have any experience with this Lidar or even a SICK Lidar? I have that one lying around too. Any tips or guidelines will be very helpful.