4 Pack HC‑SR04 Ultrasonic Distance Sensor – Non‑Contact Distance Measurement Module

HC‑SR04 Ultrasonic Distance Sensor – Non‑Contact Distance Measurement Module

Reliable HC‑SR04 ultrasonic distance sensor for non‑contact object detection and distance measurement, ideal for robotics, obstacle avoidance, smart parking, and Arduino/ESP32 projects.

HC‑SR04 Ultrasonic Distance Sensor Compatibility 

Works with Arduino, ESP32, ESP8266, Raspberry Pi, STM32, and most microcontroller platforms using standard TRIG and ECHO digital pins. The module is typically powered at 5V, and ESP32/3.3V systems may require Echo pin level shifting or protection depending on the setup.

Key Features 

Non‑contact ultrasonic distance measurement from approximately 2 cm to 400 cm, making it useful for obstacle sensing and range finding.

Good measurement accuracy, commonly specified up to about 3 mm under suitable conditions.

Simple 4‑pin interface with VCC, TRIG, ECHO, and GND for easy wiring into beginner and advanced projects.

Operates by transmitting an ultrasonic burst at 40 kHz and measuring the echo return time to calculate distance.

Widely used, affordable, and well supported by Arduino and ESP32 tutorials, libraries, and example code.

Technical Specs

Sensor type: HC‑SR04 ultrasonic ranging module.

Operating voltage: typically 5V DC.

Operating current: typically around 15 mA during measurement, with low standby current.

Measurement range: approximately 2 cm to 400 cm, with some guides noting best real‑world performance closer to 10 cm to 250 cm depending on surface and environment.

Ultrasonic frequency: 40 kHz.

Measuring angle: typically around 15°.

Trigger input: 10 µs HIGH pulse to start a measurement cycle.

Output: ECHO pulse width proportional to distance; a common formula is time in microseconds divided by 58 for centimeters.

Ideal Uses

Obstacle avoidance for robots, rovers, and autonomous vehicles.

Distance measurement in parking, tank level, and object detection projects.

Educational electronics projects for learning timing, sensors, and real‑world measurement with microcontrollers.

Interactive installations and smart devices that need low‑cost proximity sensing.

What’s Included

1 × HC‑SR04 Ultrasonic Distance Sensor Module.

Safety Note

This sensor performs best on solid, flat targets and can give weaker or less accurate readings on soft, angled, narrow, or sound‑absorbing surfaces. When using with 3.3V microcontrollers such as ESP32, protect the ECHO line appropriately if your board is not 5V tolerant.