DFRobot Gravity URM09 Analog Ultrasonic Sensor - 2cm to 500cm Range, 30Hz, 3.3V/5V

The URM09 provides an analog voltage output that is linearly proportional to the measured distance. Connect the signal wire to an analog input pin (ADC) on your microcontroller (e.g., Arduino A0). The output voltage will scale from 0V (or near 0V) at the minimum range to your supply voltage (Vcc) at the maximum 500cm range. You can map the ADC reading to a distance value in centimeters using your code.

The sensor incorporates an internal temperature sensor that automatically adjusts the speed-of-sound constant used in its distance calculations. This compensation happens onboard, requiring no user intervention or external calibration. This feature ensures measurement accuracy remains within 1% across the specified -10°C to +70°C operating range, making it reliable for environments with temperature variations.

Yes, the URM09 is fully compatible with 3.3V logic systems. Its power supply range of 3.3V to 5.5V means you can power it directly from a 3.3V pin. The analog output signal will also be referenced to this 3.3V supply, providing a safe voltage level for the ADC input of 3.3V microcontrollers without risk of damage.

The sensor has a specified range of 2cm to 500cm. The 2cm minimum is due to the physical recovery time of the transducer after emitting a pulse. The 500cm maximum can be influenced by object size, surface material, and environmental conditions like air turbulence or high humidity. For best results, target large, flat, solid surfaces perpendicular to the sensor.

The 30Hz maximum update rate (30 distance readings per second) enables real-time, dynamic sensing crucial for fast-moving applications like robot navigation or object tracking. To utilize this speed, your control code should read the analog output as fast as possible, avoiding long delays. The sensor continuously measures; you simply sample its output at your desired rate up to 30Hz.