Ultrasonic Distance Sensor Module - HC-SR04

The HC-SR04 Ultrasonic Distance Sensor Module is a popular and cost-effective sensor used for measuring distances to objects without physical contact. It utilizes ultrasonic waves to determine the distance, making it suitable for various applications in robotics, automation, and electronics projects.   

Description

The HC-SR04 module consists of an ultrasonic transmitter, a receiver, and a control circuit. The transmitter emits a short burst of ultrasonic waves at a frequency of 40kHz. These waves travel through the air and, upon encountering an object, reflect back towards the sensor. The receiver detects the reflected waves, and the module's control circuit calculates the time taken for the waves to travel to the object and back. This time is then used to determine the distance to the object.   

Key Features

• Non-contact distance measurement: Measures distance without any physical contact with the object.  
• Wide measurement range: Can measure distances from 2cm to 400cm.   
• High accuracy: Offers relatively accurate distance measurements.   
• Easy to use: Simple to interface with microcontrollers like Arduino.   
• Low cost: Affordable and readily available.

Applications

• Robotics: Used for obstacle avoidance, navigation, and distance sensing in robots.
• Automation: Employed in automated systems for object detection, distance measurement, and triggering actions.   
• Electronics projects: Suitable for various projects requiring distance measurement, such as parking sensors, liquid level measurement, and security systems.

Specifications

• Operating voltage: 5V DC   
• Operating current: <15mA
• Frequency: 40kHz   
• Measurement range: 2cm to 400cm   
• Accuracy: ±3mm   
• Sensing angle: 15 degrees
• Dimensions: 45mm x 20mm x 15mm

Additional Information

• The HC-SR04 module has four pins: VCC (5V power), GND (ground), Trig (trigger input), and Echo (echo output).   
• To initiate a measurement, a short pulse (10µs) is sent to the Trig pin.   
• The Echo pin outputs a pulse whose duration is proportional to the distance to the object.
• The distance can be calculated using the formula: Distance = (Speed of sound × Time) / 2.
• The speed of sound in air is approximately 340m/s.