# Gravity: mmWave C4001 24GHz Human Presence Detection Sensor (12 Meters, I2C & UART) **Type:** Product page · **SKU:** SEN0610 · **Brand:** [DFRobot](https://core-electronics.com.au/brands/dfrobot-australia) **Page:** https://core-electronics.com.au/gravity-mmwave-c4001-24ghz-human-presence-detection-sensor-12-meters-i2c-uart.html ([markdown](https://core-electronics.com.au/gravity-mmwave-c4001-24ghz-human-presence-detection-sensor-12-meters-i2c-uart.html.md)) The Gravity: C4001 24GHz mmWave sensor excels in human presence detection and motion sensing. Features long-distance range (12m), distance and speed... ## Pricing - **Price:** $21.40 (inc GST) — $19.45 AUD, exc GST - **Quantity discounts:** 6+ $18.48 (exc GST) · 12+ $17.70 (exc GST) ## Availability & dispatch - In stock, ships same business day if ordered before 2PM (Australia/Sydney). - We can dispatch 4 today, and up to 500 more in 8–12 days. ## Restrictions **For use in Australia** - Operate only in bands and with settings that are permitted for your location and application. Check this product’s supported frequencies in the description/specs. - If you intend to operate outside shared/licence‑exempt conditions (e.g. in other bands, at higher power, with high‑gain antennas, or extended duty cycles), you must have the appropriate authorisation. **For use in other regions** - Follow the spectrum rules for your country/region and select frequencies and settings accordingly. A declaration of use will need to be submitted during checkout. ## Description The Gravity: C4001 millimeter-wave presence sensor, operating at a wavelength signal of 24GHz, boasts a horizontal detection range of 100°, a presence detection range of 8 meters,and a motion detection and ranging range of 12 meters. It utilizes the Gravity interface (PH2.0) and supports I2C and UART communication methods, compatible with [Arduino](https://core-electronics.com.au/arduino.html), [Raspberry Pi](https://core-electronics.com.au/raspberry-pi.html), [ESP32 / ESP8266](https://core-electronics.com.au/development-boards.html) development boards.Perfect for human presence detection, environmental monitoring, and real-time monitoring projects. **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](https://core-electronics.com.au/attachments/localcontent/1_64512ee9325.jpg) The differences between millimeter-wave presence sensor and infrared sensor **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 graduallychanging 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 radarsuitable 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](https://core-electronics.com.au/attachments/localcontent/3_81413459f03.jpg) Detection Range of millimeter-wave human body sensor **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](https://core-electronics.com.au/attachments/localcontent/2_43171e58cbe.jpg) Top Installation Diagram of millimeter-wave human body sensor ![Bottom Installation of millimeter-wave human body sensor](https://core-electronics.com.au/attachments/localcontent/3_446274247e9.jpg) Bottom Installation of millimeter-wave human body sensor ![Horizontal Installation of millimeter-wave human body sensor](https://core-electronics.com.au/attachments/localcontent/4_52731b1bb9f.jpg) Horizontal Installation of millimeter-wave human body sensor ![Wiring diagram of millimeter-wave human body sensor and Arduino Uno](https://core-electronics.com.au/attachments/localcontent/3_21638d87051.png) Wiring diagram of millimeter-wave human body sensor and Arduino Uno ### Features - Communication Methods: It supports two communication methods, I2C and UART. - Interface: It uses the Gravity interface (PH2.0). - Human Detection: It can detect the presence of humans up to 8 meters and detect human motion up to 12 meters. - Distance Detection: It can measure distances from 1.2m to 12m. - Speed Detection: It can detect speeds from 0.1m/s to 10m/s. - Strong anti-interference capability: It is not affected by factors such as snow, haze, temperature, humidity, dust, light, and noise. - Compact size and easy integration. ### Applications - Human Detection - Distance and Velocity Detection - Environmental Monitoring - Industrial Automation - Real-time Monitoring and Tracking ### Specification - Operating Voltage: 3.3V/5V - Maximum Detection Range: 12m - Beam Angle: 100\*80° - Modulation Mode: FMCW - Operating Frequency: 24GHz - Operating Temperature: -40°C ~ 85°C - Baud Rate: 9600 - I2C Address: 0x2A/0x2B - Size: 22\*30mm ### Documents - [Product wiki](https://wiki.dfrobot.com/SKU_SEN0610_Gravity_C4001_mmWave_Presence_Sensor_12m_I2C_UART) - [Dimensional diagram](https://core-electronics.com.au/attachments/localcontent/cc7974df3517cfc57f7abab07b6cf609_1418894c51c.pdf) ### Parts List - Gravity: mmWave 24GHz Human Presence Detection Sensor (12 Meters, I2C & UART) x1 - Gravity-4P I2C/UART Sensor Connector x1 ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/S/E/SEN0610-1.jpg)