Gravity: mmWave C4001 24GHz Human Presence Detection Sensor

The Gravity: mmWave C4001 24GHz Human Presence Detection Sensor is a powerful module for real-time monitoring applications. Using advanced 24GHz millimeter-wave radar technology with FMCW modulation, it can detect both static and moving human targets within a range of 1.2–12 meters and speeds between 0.1–10 m/s.

Unlike traditional infrared sensors, the C4001 detects presence even when the subject is sitting or sleeping, and it offers robust resistance to environmental interference, including ambient light, temperature changes, humidity, dust, or noise.

Equipped with the Gravity (PH2.0) interface, the sensor supports both UART and I2C communication, making it highly versatile for integration into development boards such as Arduino, ESP32, ESP8266, and Raspberry Pi.

This module is ideal for applications requiring human detection, distance and velocity monitoring, industrial automation, and smart environmental monitoring systems. Featured By RoboticsBD.

Product Images are shown for illustrative purposes only and may differ from the actual product.

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Features:

1. Human Presence Detection: Up to 8m (static presence) and 12m (motion detection).

2. Distance Measurement: Accurate ranging from 1.2m to 12m.

3. Velocity Measurement: Detects motion speeds between 0.1–10 m/s.

4. FMCW Radar Modulation: Continuous measurement of distance and velocity with high resolution.

5. Anti-Interference: Immune to environmental factors like light, haze, temperature, humidity, and dust.

6. Wide Detection Angle: 100° × 80° horizontal/vertical field of view.

7. Compact Size: Only 22 × 30 mm, easy to embed into systems.

8. Communication Interfaces: Supports both I2C (0x2A/0x2B) and UART.

9. Gravity Interface (PH2.0): Simplifies wiring and development.

10. Broad Compatibility: Works with Arduino, Raspberry Pi, ESP32/ESP8266, and other MCUs.

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Applications:

1. Human presence detection for automation and security.

2. Distance and speed measurement in smart monitoring systems.

3. Industrial automation and robotics.

4. Real-time environmental monitoring.

5. Smart home and IoT systems.

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Please allow 5% measuring deviation due to manual measurement.

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Documentation:

• Product wiki
• Dimensional diagram

Human detection

Compared to other types of human presence sensors, such as infrared sensors, the C4001 (12m) millimeter wave presence sensor has the advantage of detecting both static and moving objects. It also has a relatively strong anti-interference ability, making it less susceptible to factors such as temperature changes, variations in ambient light, and environmental noise. Whether a person is sitting, sleeping, or moving, the sensor can quickly and sensitively detect their presence. 

The differences between millimeter-wave presence sensor and infrared sensor

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Distance and velocity detection

The C4001 (12m) millimeter wave presence sensor utilizes FMCW modulation for distance and speed measurement. It has a maximum detection range of 12 meters and a speed measurement range of 0.1 to 10 meters per second.

FMCW (Frequency Modulated Continuous Wave) is a type of radar system based on frequency modulation of continuous wave signals. Unlike traditional pulse radar, FMCW radar continuously emits a series of continuous wave signals with gradually changing frequencies while simultaneously receiving the reflected signals. By analyzing the received signals, measurements of parameters such as distance, speed, and angle can be achieved.

Compared to traditional pulse radar technology, FMCW radar can continuously measure the distance of an object. By utilizing the Doppler effect, it can also obtain information about the velocity of the target object. This makes FMCW radar suitable for applications that require tracking the movement of objects. Additionally, FMCW radar can achieve continuous frequency scanning, providing higher measurement resolution. Since it does not require waiting for the return of echo signals, FMCW radar is suitable for applications that require real-time monitoring and tracking of target objects. 

Detection Range of millimeter-wave human body sensor

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What is a millimeter-wave radar sensor?

Millimeter-wave radar technology is a non-contact sensing technology used to detect objects and provide information about their distance, velocity, and angle (in the case of humans, for example). The signals emitted by millimeter-wave sensors fall within the high-frequency spectrum with wavelengths between 24GHz and 300GHz, also known as the millimeter (mm) range.

Installation Method

The millimeter-wave human body sensor is sensitive to the installation method, and improper installation can affect the performance and functionality of the sensor. The commonly used installation methods for this module include top installation, bottom installation, horizontal installation, and downward tilted installation.

Top Installation Diagram of millimeter-wave human body sensor

 Bottom Installation of millimeter-wave human body sensor

 Horizontal Installation of millimeter-wave human body sensor 

Wiring diagram of millimeter-wave human body sensor and Arduino Uno

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Package Includes:

1 x Gravity: mmWave C4001 24GHz Human Presence Detection Sensor

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