HC-SR04 ultrasonic transceiver

HC-SR04 is an ultrasonic sensor that allows you to measure the distance to an obstacle in the range from 2 to 400 cm. It can be used as a presence sensor in a smart home or security system, as well as for various robotic systems. In addition, using this module, you can make parking sensors for a car.

The module is a board on which an ultrasonic emitter, a receiver and a control electronic circuit are placed. The sensor has small dimensions and a simple interface: two power outputs (VCC and GND), an input (TRIG) and an output (ECHO) for data transfer between the controller and the module.

The emitter transmits a short ultrasonic pulse, which is reflected from the object and received by the sensor. The distance is calculated from the time to echo and the speed of sound in air. The receiver receives the echo signal and outputs the distance, which is encoded by the duration of the electrical signal at the output of the sensor. The next pulse can only be emitted after the echo from the previous one has disappeared. This time is called the cycle period. The recommended period between pulses should be at least 50 ms. If a 10 µs pulse is applied to the TRIG signal pin, the ultrasonic module will emit eight bursts of ultrasonic signal at a frequency of 40 kHz and detect their echo. The measured distance to the object will be proportional to the width of the echo pulse.

Module Specifications:

Supply voltage, V 3.3 ... 5
Effective viewing angle, ° 15
Operating viewing angle, ° 30
Maximum measuring distance

Source https://arduino.ua/art21-yltrazvykovoi-dalnomer-hc-sr04
, m 4
Current consumption in silence mode, mA 2
Operating current, mA 15
Operating frequency, kHz 40
Sensor dimensions, mm 45 x 20 x 15.