An ultrasonic proximity sensor emits and detects ultrasonic sound waves and can measure distance based on that.

Working Principle

A pulse can be given on the input pin, on which the module outputs a sound wave. The sound wave bounces off an object (if present) and is picked up by the module, on which the module outputs a pulse on the output. The time difference between the input and output pulse is a proportional measure for the distance between the sensor and the object. Short times reflect short distances. The speed of sound in air is roughly 340 meters per second at room temperature.

NOTE: sound waves can disperse quickly in windy conditions, outside use is not recommended.

NOTE2: restrict usage to maximum 1 operating sensor in your prototype at any time; multiple ultrasonic sensors will interfere with each other.

NOTE3: hard objects reflect sound very well as opposed to soft foam like structures.


5V Supply
Trigger Pulse Input
Echo Pulse Output
0V Ground

Quick Specs

Working Voltage : 5V(DC)
Quiescent Current: Less than 2mA.
Output Signal: Electric frequency signal, high level 5V, low level 0V.
Sensor Angle: < 15°
Detection Distance: 2cm-450cm.
Precision: 0.3cm ± 1%
Working temperature: -20°C to +70°C
Input Trigger Signal: 10μs TTL impulse
Echo Signal : output TTL PWL signal