hi..
Search in this site about interfacing ultrasonic sensors u ll get a bunch of information..
Connect the ultrasonic reciever module with the microcontroller.. I mean connect it to a single port pin (I/O).. Keep it on polling or use interrupt concepts for detecting a sensed signal change...
The ultrasonic sensor which works within 40-50KHz schematic is as follows... It works...
Dont fail to search the site.. as i said u ll get lot of different details...
All the best
regards..
Sujith