how to build an ultra sonic sensor using ultrasonic dectors

[vvarlord]

i'm working on a project to implement a distance to an obstacle sensor using a 2pin ultarsonic transmitter and a 2pin ultrasonic reciever and an atmega 8
i don't know what to start with
how to make the transmitter and reciever get working?
should i just connect them to micro or a circuit is needed
i just want to know how to get started
tnx in advance

 

[HTA]

Here you find a complete description of an ultrasonic sensor with signal conditioning: **broken link removed** .

Enjoy your design work!