The HC-SR04 is a popular and affordable ultrasonic distance sensor module commonly used in robotics, automation, and other applications where distance measurement is required. It uses ultrasonic sound waves to measure distances by sending out a pulse and timing how long it takes for the pulse to bounce back after hitting an object.
Key Features:
- Working Principle: The sensor operates based on the time-of-flight principle. It emits an ultrasonic pulse and measures the time it takes for the pulse to reflect off an object and return to the sensor. This time can then be used to calculate the distance to the object.
- Measurement Range: The HC-SR04 sensor can typically measure distances in the range of 2 cm to 400 cm (0.79 inches to 157.48 inches).
- Accuracy: The accuracy of the sensor’s distance measurement can vary based on factors such as temperature, humidity, and surface properties of the object being measured.
- Components: The module consists of an ultrasonic transducer (which emits and receives ultrasonic pulses) and control circuitry to generate the pulses, measure the time delay, and calculate the distance.
- Operating Voltage: The HC-SR04 sensor module is designed to work with 5V power supplies.
- Trigger and Echo Pins: The sensor has two main pins: the trigger pin (often labeled as “Trig”) and the echo pin (labeled as “Echo”). The trigger pin is used to send out the ultrasonic pulse, while the echo pin is used to receive the pulse after it bounces off an object.
- Interfacing: To use the sensor, you typically need to provide a short trigger pulse to the trigger pin and then measure the time it takes for the echo pulse to return. This can be done using a microcontroller or a single-board computer.
- Calculating Distance: The time taken for the pulse to travel to the object and back can be used to calculate the distance using the formula: Distance = (Time × Speed of Sound) / 2. (Note that the speed of sound varies with temperature).
- Applications: The HC-SR04 sensor is commonly used for object detection, obstacle avoidance, level measurement, and proximity sensing in various projects.
