Working Principle: The HC-SR04 sensor emits ultrasonic sound waves (inaudible to humans) from its transmitter. These sound waves travel through the air until they encounter an object. When the sound waves hit the object, they bounce back towards the sensor. The sensor then measures the time it takes for the sound waves to return.
Distance Measurement: By knowing the speed of sound in the air (approximately 343 meters per second at room temperature), the sensor can calculate the distance to the object using the time it takes for the sound waves to make a round trip.
Operating Range: The HC-SR04 sensor typically has an operating range of about 2 centimeters (cm) to 400 cm or 1 inch to 13 feet, depending on the specific module and environmental conditions.
Accuracy: The accuracy of distance measurements with the HC-SR04 can vary, but it's generally sufficient for many applications, especially when used within its specified range.
Ultrasonic Transducer: The sensor consists of two main components: a transmitter (ultrasonic transducer) and a receiver (ultrasonic transducer). These components work together to emit and receive sound waves.
Trigger and Echo Pins: The HC-SR04 sensor typically has two pins: a trigger pin (often labeled "Trig") and an echo pin (often labeled "Echo"). To initiate a measurement, a microcontroller sends a short pulse to the trigger pin. The sensor then emits an ultrasonic pulse, and the echo pin goes high when the sound waves are detected.
Interfacing: The HC-SR04 sensor is easy to interface with microcontrollers like Arduino, Raspberry Pi, and others. You can use simple code to control the sensor and obtain distance measurements.
Power Supply: The sensor is typically powered with 5V DC and consumes a low amount of power during operation.
Applications: HC-SR04 sensors are widely used in robotics for obstacle avoidance, distance measurement, and navigation. They are also used in automation, smart parking systems, and various DIY electronics projects.
Mounting: The sensor can be easily mounted on a variety of surfaces or platforms, and it can be integrated into existing systems.
Considerations: When using the HC-SR04 sensor, it's important to consider factors such as temperature (which affects the speed of sound), interference, and acoustic properties of the object being detected.
Multiple Sensors: You can use multiple HC-SR04 sensors in parallel to obtain information about objects in different directions or at different distances.
