Sensor HC-SR04 Ultrasonic Distance Module

Description

The HC-SR04 Ultrasonic Distance Module is essentially the “eyes” of a robot, acting much like a bat’s sonar. It uses sound waves to detect how far away an object is with remarkable accuracy for its low cost.

Product Description

The module consists of two silver cylinders: one is a transmitter (which sends out an ultrasonic high-frequency sound) and the other is a receiver (which listens for the echo). By measuring the time between sending the signal and receiving the bounce-back, the sensor calculates the distance to the target.

It is the most popular distance-sensing choice for hobbyist electronics because it is easy to program and works reliably in both light and dark environments, as it relies on sound rather than light.

Key Features

• Non-Contact Measurement: Detects objects from a distance without physical contact.
• High Precision: Offers stable readings with an accuracy of up to 3mm under ideal conditions.
• Small Footprint: Compact design makes it easy to mount on robot chassis or small project enclosures.
• Simple 4-Pin Interface: Requires only Power (VCC), Ground (GND), a Trigger pin to start the pulse, and an Echo pin to receive the result.

Common Applications

• Obstacle Avoidance Robots: The “brain” of the robot uses this to decide when to turn to avoid hitting a wall.
• Liquid Level Sensing: Mounted at the top of a water tank to measure how full it is without touching the liquid.
• Digital Tape Measure: Create a handheld device that displays the distance to a wall on an LCD screen.
• Parking Sensors: DIY versions of the sensors found in modern car bumpers to alert you as you get close to an object.
• Intrusion Alarms: Detecting when someone passes through a doorway or enters a specific range.