Beyond Traditional PIR Limits, delivers "True Presence" Automation with Micro-Motion Detection. Traditional PIR sensors often fail to detect stationary occupants, leading to inconvenient lighting deactivation. The Fermion: C4002 mmWave radar module resolves this by utilizing 24GHz FMCW technology to detect micro-motions (such as breathing and chest expansion). Capable of distinguishing between moving, stationary, and micro-moving targets within a 10×10 meter range, this module serves as a reliable core component for smart lighting, HVAC control, and security monitoring in Home Assistant and IoT systems.

Streamlined Home Assistant Integration

Designed to simplify the development process, eliminating the need for complex reverse-engineering.

• Hardware Ready: Standard UART interface connects easily to ESP32 controllers.
• Software Ready: Fully compatible with ESPHome (Home Assistant). A verified YAML configuration file is provided for immediate deployment.
• Instant Entities: Automatically exposes "Occupancy," "Distance," and "Energy" entities in Home Assistant upon flashing.

True Static Presence Detection (10x10m Range)

Capable of detecting individuals who are sitting, sleeping, or standing completely still. Ideal for bedrooms, offices, and bathrooms.

• Motion Detection: Up to 11m (Walking / Running).
• Static Detection: Up to 10m (Reading / Typing / Sleeping).

Precision Control for Complex Environments

Unlike passive sensors with fixed ranges, the C4002 offers a software-configurable detection distance. This capability allows for precise matching of the sensor's coverage to the physical room layout.

• Targeted Monitoring: Configure the sensor to cover only specific functional areas (e.g., a sofa or workspace) while strictly ignoring movement in adjacent backgrounds (e.g., hallways or open doors).
• Wall Penetration Management: By setting a maximum distance threshold, users can prevent the radar signal from penetrating thin walls and detecting activity in neighboring rooms.
• Adaptability: Suitable for diverse spaces, ranging from small bathrooms to large open-plan living rooms.

Intelligent Environmental Filtering

To prevent false triggers common in radar technology (e.g., swaying plants, moving curtains), the C4002 incorporates adaptive background noise learning. The module automatically establishes a noise model of the environment, filtering out non-human interference to ensure triggers occur only upon actual human presence.

Specifications:

• Operating Voltage: 3.6 ~ 5.5V
• Detection Capability: Motion, Micro-Motion / Stationary Human Body
• Max Detection Distance: Motion 11m, Micro-Motion / Stationary 10m
• Detection Angle: 120° x 120°
• Output Interface: OUT (Configurable IO), UART
• Operating Frequency: 24GHz ~ 24.25GHz
• Light Detection: 0 ~ 50 lux
• Operating Temperature: -20 ~ 85 ˚C
• Product Dimensions: 22mm x 26mm

Applications:

• Smart Lighting Automation: Maintains lighting based on true presence (breathing/micro-motion) rather than large movements, solving the problem of lights turning off while reading or working.
• HVAC Energy Management: Automatically activates air conditioning or heating only when the room is actually occupied, optimizing energy efficiency in homes or offices.
• Privacy-Friendly Elderly Care: Detects presence or prolonged inactivity in bedrooms or bathrooms without the need for invasive cameras or wearable devices.
• Concealed Security: Capable of detecting intrusion through thin non-metal obstacles (like decorations or thin walls), allowing for a completely hidden security setup.

Documentations:

• Product Wiki (Guides & Pinout)
• Arduino Library
• ESPHome Configuration (YAML)
• Tutorial - Building a Native Home Assistant MmWave Presence Sensor With ESPHome on ESP32-C6

Package Includes:

• 1x Fermion: C4002 mmWave Human Presence Sensor
• 1x 5-pin Header