This sensor provides precise, non-contact distance measurements from about 2 cm to 3 meters. The PING))) sensor works by transmitting an ultrasonic burst and providing an output pulse that corresponds ...

This unit uses a Ping ultrasonic range finder to input a four digit code. It’s a hardware upgrade, but uses the same basic concept as his button-based combo lock.

This one uses a single ultrasonic rangefinder which we think is much simpler. It’s accurate to about 1cm and is simple to use — it’s very popular with the hobby electronics crowd which helps ...

In this paper we design and implement an embedded surveillance system by use of ultrasonic signal coding of ultrasonic sensors with multiple pyroelectric infrared sensors (PIR) to detect an intruder ...