The typical operating frequency of an ultrasonic sensor commonly used with Arduino is 40 kHz.
Understanding the Frequency of Arduino Ultrasonic Sensors
Ultrasonic sensors, widely popular for distance measurement projects with platforms like Arduino, function by emitting a high-frequency sound pulse and measuring the time it takes for the echo to return. The frequency at which these sensors operate is key to their functionality.
According to reliable sources regarding these modules:
- This ultrasonic module uses 40 kHz sound waves.
- The audible frequency of the human ear ranges from 20 to 20 kHz.
- The sound frequency of the module is more than twice the upper limit of the human ear.
This means the 40 kHz frequency is well beyond the range of human hearing, classifying the sound as "ultrasonic."
Here's a simple comparison:
| Frequency Type | Range | Description |
|---|---|---|
| Human Hearing | 20 Hz - 20 kHz | Sounds detectable by people |
| Ultrasonic Sensor | 40 kHz | High-frequency sound pulse |
Operating at 40 kHz allows the sensor to reliably detect objects using sound waves that won't interfere with human activities or be perceived as noise. Modules such as the popular HC-SR04, frequently interfaced with Arduino, operate at this standard 40 kHz frequency.
This 40 kHz pulse is emitted by a transducer and bounces off an object, with the echo being received by another transducer (or the same one depending on the sensor type). The time difference is then used by the Arduino to calculate the distance to the object.
