RA24A18 24GHz Presence Sensor Module – Human Motion Presence Sensor Module mmWave Radar Technology:
📝 Product Description
The RA24A18 24GHz radar module is a compact presence sensor designed to detect whether people are in a room, moving around, or even staying still. Using advanced 24GHz FMCW radar technology, it can pick up everything from obvious movements like walking or turning, to small gestures like using a phone or flipping a book.
Unlike traditional motion sensors, this module works even when people are sitting quietly, making it ideal for smart lighting, home automation, offices, and hotel energy-saving systems. It is also reliable in different weather and lighting conditions, and can sense through materials like glass, plastic, thin wood, or clothing.
Its small size, low power use, and accurate detection make it easy to integrate into products where smart presence detection is needed.
🔧 Key Features
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Detects human motion, micro-movements, and static presence
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Works reliably through glass, plastic, and thin walls
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Stable operation, not affected by light, temperature, snow, or fog
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Strong interference suppression for fewer false triggers
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Compact module, supports UART communication
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Can be ceiling or wall mounted
📋 Technical Specifications:
| Parameter | Value |
|---|---|
| Frequency | 24 – 24.25 GHz (ISM band) |
| Detection Range (Wall Mount) | Motion: up to 6m / Presence: up to 6m |
| Detection Range (Ceiling Mount) | Motion: up to 4m / Presence: up to 4m |
| Beam Angle | 100° × 80° |
| Refresh Rate | 150 ms |
| Operating Voltage | 4.5V – 8V |
| Operating Current | ~20mA |
| Delay Time | 2s – 3600s (adjustable) |
| Light Sensitivity | 10 Lux (adjustable) |
| Operating Temp | -25°C to +85°C |
| Storage Temp | -40°C to +125°C |
| Humidity | 5% – 95% RH |
| Output Level | 3.3V (High), 0V (Low) |
| Recommended Ceiling Height | ≤ 4.5m |
| Module Size | Compact PCB (see datasheet for exact mm) |
🌍 Applications
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🏠 Smart home lighting & HVAC automation
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🔒 Security & surveillance systems
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🏭 Industrial occupancy monitoring
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🚗 Automotive in-cabin detection & safety
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📡 IoT and AI-based sensing devices
How it works:
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Unlike PIR (infrared) sensors, which only detect motion, this mmWave radar sensor uses Doppler + micro-motion detection.
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It senses breathing, small body vibrations, or subtle movements that happen naturally, so it knows if someone is present even when not actively moving.
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This makes it useful for occupancy detection in offices, smart homes, and lighting systems.
⚠️ Note:
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Detection range and accuracy depend on installation (angle, distance, environment).
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If a person sits completely still and holds their breath, the detection may become weaker, but in normal situations (breathing, slight posture adjustments) it will detect presence.
📦 Package Includes
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1 × RA24A18 24GHz Presence Sensor Module
Horizontal installation
Top installation