6m 24GHz mmWave Person Presence Sensor

The DFRobot SEN0557 is a highly sensitive 24GHz mmWave radar module based on the LD2410 chip with FMCW technology (Frequency-Modulated Continuous Wave) for detecting moving and stationary people. Unlike PIR sensors, which only respond to movement, the LD2410 can also detect motionless people through micro-movements such as breathing and subtle body movements. The detection range is up to 6 m with a resolution of 0.75 m.

Features:

24GHz FMCW radar (LD2410) detects moving and statically still people through micro-motion detection – overcomes the PIR blind spot for stationary people
Detection range up to 6 m with 0.75 m resolution; configurable detection zone with range-specific sensitivity and decay delay via UART
Material penetration capability: FMCW radar works through casing materials – no installation hole in the casing required
Insensitive to temperature, brightness, humidity, and light fluctuations for stable detection performance in changing environments
Dual output: UART (serial, configurable) and GPIO (high/low level) for direct device connection without a microcontroller
Configurable detection sensitivity, decay time, and zone division via serial protocol for application-specific customization

Application Examples:

Smart home lighting control that remains active for stationary people (reading, sleeping) and doesn't mistakenly turn off
Office access control and energy management for HVAC systems based on actual presence in the room
Indoor security monitoring with detection of unauthorized people even with minimal movement
Service robotics for people detection and safe stopping upon approaching people in the detection area
Industrial machine protection systems with reliable person detection independent of ambient light and temperature