DFRobot 24GHz Human Presence Detection Sensor - 25m (UART)

The C4001 is a high-performance millimeter-wave presence sensor that operates at 24GHz, offering reliable detection of both static and moving targets. With a horizontal field of view of 100°, it can detect human presence within 16 meters and motion or distance up to 25 meters. Unlike infrared or ultrasonic sensors, it is resistant to environmental interference such as temperature shifts, light changes, humidity, or dust—making it ideal for real-world monitoring applications.

Using Frequency Modulated Continuous Wave (FMCW) radar, the sensor delivers precise distance (1.2–25m) and velocity (0.1–10 m/s) measurements. By leveraging continuous frequency scanning and the Doppler effect, it provides real-time tracking with high resolution. Its compact form factor with UART and I/O support ensures easy integration into smart monitoring, automation, and security projects.

Quick Spec

• Operating Voltage: 3.3V / 5V
• Operating Frequency: 24GHz
• Modulation Mode: FMCW
• Human Presence Detection Range: up to 16m
• Motion & Distance Detection Range: up to 25m
• Velocity Detection Range: 0.1–10 m/s
• Beam Angle: 100° × 40°
• Baud Rate: 9600
• Strong anti-interference (resistant to light, noise, temperature, dust, humidity, haze, snow)
• Operating Temperature: -40 to 85℃
• Size: 26 × 30 mm

Millimeter-wave Presence Sensor VS Infrared Sensor

Compared to other types of presence sensors such as infrared sensors and ultrasonic sensors, the C4001(25m) millimeter-wave presence sensor has the advantage of being able to detect 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 in motion, the sensor can quickly and sensitively detect their presence.

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

Bottom Installation

Horizontal Installation

Wiring Diagram

Resources

• Product Page
• Product Wiki
• Communication Protocol
• Mechanical Diagram
• DFRobot_C4001 Library

Shipping List

• 1 x DFRobot 24GHz Human Presence Detection Sensor - 25m (UART)
• 1 x 5-Pin SIL Male Header