HC-SR04 Ultrasonic Sensor

The HC-SR04 is the world's most widely used ultrasonic distance sensor — and for good reason. It measures distances from 2 cm to 400 cm with ±3 mm accuracy using a simple trigger/echo pulse interface, requires only two GPIO pins, and runs on 5 V. Whether you're building a robot, a parking sensor, or a liquid level monitor, the HC-SR04 is the reliable, battle-tested choice.

🔹 Key Applications

• Obstacle detection and avoidance in autonomous robots

• Parking distance sensors for vehicles and automated gates

• Liquid level monitoring in tanks and reservoirs

• Object detection on conveyor belts

• People counting systems in retail or access control

• CNC machine axis homing and position detection

🔹 Why Choose This Module?

• 2–400 cm range — covers most practical detection scenarios

• ±3 mm accuracy — precise enough for most embedded applications

• Simple 2-pin interface (Trig/Echo) — minimal GPIO usage

• 5 V operation — direct Arduino and ESP32 compatibility

• Lightweight at 8.5 g — ideal for mobile robotics

🔹 Technical Specifications

• Sensing Method: Ultrasonic (40 kHz)

• Range: 2 – 400 cm

• Accuracy: ±3 mm

• Operating Voltage: 5 V DC

• Trigger Input: 10 µs TTL pulse

• Echo Output: TTL proportional to distance

• Beam Angle: 15°

• Dimensions: 45 × 20 × 15 mm

🔹 What's Included

1 × HC-SR04 Ultrasonic Sensor Module

🔹 Pro Tip

💡 Use NewPing library on Arduino for cleaner code and non-blocking measurement. At distances below 5 cm, reflections can cause false readings — add a minimum distance check in your code. For liquid level monitoring, mount above the surface pointing straight down.

⚠️ Note: Always ensure proper heat dissipation and correct voltage configuration before powering connected devices.