Grove Ultrasonic Ranger

The Grove Ultrasonic Ranger (Seeed Studio) is a non-contact distance measurement module operating at 40 kHz. Unlike standard ultrasonic sensors that require separate trigger and echo pins, the Grove module uses a single SIG pin for both functions via an internal MCU, making it ideal for GPIO-constrained projects.

This sensor measures distances from 2 cm to 350 cm with 1 cm resolution and a 15° measurement angle. It operates at 3.2–5.2 V and draws approximately 8 mA. The sensor outputs a PWM echo whose pulse width is proportional to distance:

$$\text{Distance} = \frac{\text{echo duration} \times 340\ \text{m/s}}{2}$$

The SIG pin alternates between OUTPUT (trigger pulse) and INPUT (echo listening). Once the trigger has been sent, the component switches the pin to an input to receive the echo signal.

Configuration

# Example configuration entry
sensor:
  - platform: grove_ultrasonic
    sig_pin: GPIOXX
    name: "Distance"

Configuration Variables

• sig_pin (Required, Pin Schema): The pin connected to the yellow (SIG) wire of the Grove cable. Must support both input and output modes.

• update_interval (Optional, Time): The interval to check the sensor. Defaults to 60s.

• All other options from Sensor.

Advanced options:

• timeout (Optional, float): The number of meters before the measurement times out. The default is 3.5 meters, the maximum range of the sensor.

• id (Optional, ID): Manually specify the ID used for code generation.

Wiring

The Grove Ultrasonic Ranger uses a standard 4-pin Grove cable, but only three connections are needed:

Wire colour	Function	ESP pin
Yellow	SIG	GPIOXX
Red	VCC	3.3V/5V
Black	GND	GND
White	NC	Not connected

WARNING

Do not hot-plug the sensor. Always connect or disconnect the Grove cable while the device is powered off. Hot-plugging may damage the sensor.

See Also

• Grove Ultrasonic Ranger Wiki
• Sensor Filters
• Template Sensor
• API Reference: grove_ultrasonic.h