The two pins was connected to the Ultrasonic transducer itself and you need to provide the circuity to send and receive the signal.
Here is the link
http://www.underwaterrov.net/hacking-reverse-parking-sensors-with-an-arduino
The two pins was connected to the Ultrasonic transducer itself and you need to provide the circuity to send and receive the signal.
Here is the link
http://www.underwaterrov.net/hacking-reverse-parking-sensors-with-an-arduino