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Product Description
A high-precision, non-contact ultrasonic distance measurement sensor module, ideal for obstacle avoidance, automated mapping, and distance tracking in Arduino and robotics projects. The HC-SR04 module utilizes high-frequency sound waves to measure the distance to a target object by calculating the time-of-flight between transmitting and receiving an acoustic echo. It features two prominent cylindrical transducers—one acting as an ultrasonic transmitter and the other as a highly sensitive receiver receiver. Delivering an exceptionally stable reading range from 2 cm up to 400 cm with a measurement resolution of 3 mm, this module is an essential, easy-to-program component for autonomous robotic rovers, liquid level tracking bins, and smart security barriers.
Pinout / Layout Connections
The module breaks out its tracking interface via a standard 4-pin male header block:
VCC Pin: Connects to a stable +5V DC positive power supply line.
Trig (Trigger) Pin: Digital input pin. Pull HIGH for 10 microseconds to initiate the ultrasonic sound burst transmission.
Echo Pin: Digital output pin. Outputs a HIGH logic pulse where the duration (pulse width) is directly proportional to the distance of the detected object.
GND Pin: Connects to the common system ground (0V) reference.
Applications
Autonomous Robot Obstacle Avoidance: Perfect for mobile wheeled rovers, vacuum cleaners, and automated drones to safely detect and map walls or obstacles.
Smart Liquid & Bin Level Sensing: Excellent for monitoring trash can fullness or non-corrosive liquid storage tanks without direct physical immersion.
Contactless Industrial Gating: Ideal for implementing safe parking garage barriers, automatic door triggers, and automated hand-sanitizer or soap dispensers.
Compatibility
The HC-SR04 operates via straightforward high/low digital pulses, making it fully compatible with:
Arduino Board Series (Uno, Nano, Mega, Pro Micro) using native timing functions (
pulseIn()) or optimized libraries likeNewPing.ESP32 and ESP8266 boards (Requires a simple 5V-to-3.3V voltage divider or level shifter on the Echo pin to protect 3.3V logic inputs).
Raspberry Pi and Raspberry Pi Pico modules (with appropriate logic level conversion on the Echo line).
Standard 5V Logic Microcontrollers.
Technical Specifications
| Parameter | Value / Specification |
| Product Module Model | HC-SR04 |
| Operating Input Voltage | DC 5.0 V |
| Working Current Draw | ~15 mA |
| Ultrasonic Ranging Frequency | 40 kHz acoustic burst |
| Effective Detection Range | 2 cm to 400 cm ($1\text{ in}$ to $13\text{ ft}$) |
| Measurement Resolution | 3 mm |
| Measuring Angle Tolerance | $\le 15^\circ$ effective field of view |
| Trigger Input Pulse Requirement | 10 $\mu$s TTL High logic pulse |
What’s in the Box
1 x HC-SR04 Ultrasonic Distance Sensor Module.
