Product Description
Product Description
The DFRobot Fermion: C4002 is a mmWave presence radar sensor module for detecting human presence, motion, and micro-movements. It uses 24GHz FMCW radar technology to sense not only large body movement but also subtle motion patterns such as breathing and chest expansion. This makes it suitable for occupancy applications where conventional PIR sensors may fail to detect stationary people.
The SEN0691 variant is designed for direct integration into IoT and building automation systems. Through its UART interface, the module can be connected easily to ESP32-based controllers. According to the manufacturer, it is prepared for use with ESPHome and Home Assistant; after integration, typical entities such as occupancy, distance, and energy are available. The software-configurable detection distance helps adapt the sensing area to room geometry and defined monitoring zones.
Technical Features
- mmWave presence radar sensor module based on the Fermion C4002 radar platform
- 24GHz FMCW radar technology for motion, static presence, and micro-motion detection
- Detection area up to 10 × 10 m for static human presence
- Motion detection up to 11 m for walking or running persons
- UART interface for connection to microcontrollers, especially ESP32
- Compatible with ESPHome and Home Assistant according to manufacturer information
- Software-configurable detection distance for application-specific coverage adjustment
Application Areas
This module is intended for indoor presence and occupancy sensing. Typical applications include lighting control, HVAC control, security and monitoring functions, and general IoT systems with state-dependent automation. Because it can detect stationary occupants, the sensor module is particularly suitable for bedrooms, offices, bathrooms, and other spaces where people may remain in place for extended periods with minimal movement.
The configurable sensing range can also be used to monitor specific zones while reducing unwanted detection from adjacent background areas. This is useful in open layouts or installations near corridors and doorways.
What's Included
- Fermion: C4002 mmWave Human Presence Sensor x1
- 5-pin Header x1
