HC-SR04 Ultrasonic Sensor: Non-Contact Distance Measurement Using Time-of-Flight

HC-SR04 Ultrasonic Range Finder Module

The HC-SR04 is the essential, low-cost sensor for all your distance measurement and object detection projects. Operating on the principle of SONAR (sound navigation and ranging), this module provides reliable, non-contact ranging from $2\text{ cm}$ up to $400\text{ cm}$. It’s a must-have component for hobbyists, students, and engineers working on robotics and automation.

Key Features

• Wide Ranging Distance: Accurately measures distances from $2\text{ cm}$ to $400\text{ cm}$ (or $13\text{ feet}$).
• High Precision: Offers ranging accuracy up to $3\text{ mm}$.
• Easy Interface: Simple 4-pin interface ($\text{VCC},\text{GND},\text{Trig},\text{Echo}$) is easily compatible with $5\text{V}$ microcontrollers like Arduino Uno, Raspberry Pi, and other development boards.
• Stable Performance: Not affected by sunlight or black materials, unlike many IR (Infrared) rangefinders.
• Low Power Consumption: Operates with a static current of less than $2\text{ mA}$.

Technical Specifications

Common Applications

• Robotics: Obstacle avoidance for smart cars and robots.
• Proximity Sensing: Creating simple motion or presence detectors.
• Automation: Liquid level measurement in tanks (non-contact).
• DIY Projects: Parking assist systems, smart trash cans, and security alarms.