SeeedStudio Grove Ultrasonic Sensor Module

Working on distance measurement projects? Need a sensor for it? We have Grove – Ultrasonic Ranger especially for you. It is an Ultrasonic Distance Sensor v2.0 i.e. a transducer that utilizes ultrasonic waves to measure distance; moreover, it is a non-contact distance measurement module that works at 40 kHz and can measure from 3 cm to 350 cm with an accuracy up to 2 mm.

The required documents and libraries for Arduino, Python, and Codecraft are provided in the ATTACHMENT section so that you can use this sensor with Arduino and Raspberry pi easily. With a wide voltage range, single I/O pin as well as plug and play Grove connector, this module is designed with the best efforts to make it easier to use and reduce your work. For all Grove users (especially beginners), Seeed Studio has provided guidance PDF documents. Please download and read through Preface – Getting Started and Introduction to Grove before using the product. This is a suitable product for not only Grove users but also all electronic enthusiasts. We hope you like it.

Warning: Do not hot-plug the Grove-Ultrasonic Ranger, otherwise it will damage the sensor. The measured area must be no less than 0.5 square meters and smooth.

Hardware Overview:

This module has an ultrasonic transmitter and an ultrasonic receiver so you can consider it as an ultrasonic transceiver. It has 4 pins with their functions as shown in the figure above. When the 40 kHz ultrasonic wave generated by the transmitter encounters the object, the sound wave will be emitted back, and the receiver can receive the reflected ultrasonic wave. It is only necessary to calculate the time from the transmission to the reception, and then multiply the speed of the sound in the air (340 m/s) to calculate the distance from the sensor to the object.

Here is the formula: Distance = Echo Signal High Time * Sound Speed (340M/S)/2.

When we provide a pulse trigger signal with more than 10uS through the signal pin, the Grove – Ultrasonic Ranger will issue 8 cycles of 40kHz cycle level and detect the echo. The pulse width of the echo signal is proportional to the measured distance. Grove – Ultrasonic Ranger’s trig and echo signal share 1 SIG pin.

Comparison with HC-SR04

You might wonder why there is a need for this sensor when ultrasonic module HC-SR04 is already available in the market. The comparison of Grove – Ultrasonic Distance Sensor and traditional ultrasonic module HC-SR04 is as follows:

1. The Grove – Ultrasonic Distance Sensor integrates a single-chip microcomputer, and the transmitting signal and the receiving signal share one pin by Time Division Multiplexing (TDM), so only one I/O pin is occupied. The HC-SR04 Ultrasonic (US) sensor comes with a 4 pin interface named VCC, Trig (signal output pin), Echo (signal input pin), and GND.
2. Grove – Ultrasonic Distance Sensor module supports 3.3V as well as 5 V, but HC-SR04 only supports 5v voltage. As we know, the Raspberry pi I/O only supports 3.3v. Therefore, Grove – Ultrasonic Distance Sensor can be directly connected to the I/O of the Raspberry Pi, but HC-SR04 needs to use a voltage conversion circuit. The image of both the modules is as given below.

Package Includes:

1 x SeeedStudio Grove Ultrasonic Sensor Module