HLK-LD1125H-24G 24GHz Human Presence Radar Sensor – FMCW Breathing and Motion Detection
₹1,003.00 incl. GST (₹850.00 + GST)
HLK-LD1125H-24G 24GHz Human Presence Radar Sensor is an FMCW millimeter-wave radar module designed for human presence, motion, and micro-motion detection, including breathing-related movement. With 23.5–24.5GHz operation, 8m+ motion detection, 4m+ static presence detection, 3.3V–5V input, and 3.3V serial output, it is ideal for smart lighting, HVAC, security, IoT, automation, and Arduino/ESP32 projects.
HLK-LD1125H-24G 24GHz Human Presence Radar Sensor – FMCW Motion & Micro-Motion Detection Module
Product Description
The HLK-LD1125H-24G is a compact 24GHz FMCW millimeter-wave radar sensor module designed for human presence detection, motion sensing, and micro-motion monitoring. Unlike conventional PIR sensors, the radar can detect subtle human movements such as breathing, allowing systems to recognize continued human presence even when a person remains relatively stationary.
The module operates in the 23.5GHz to 24.5GHz frequency range and can detect moving targets at distances greater than 8m under suitable conditions. It also supports static human presence detection at distances greater than 4m, depending on installation height, target conditions, environmental reflections, and configuration.
The HLK-LD1125H-24G provides a 3.3V serial ASCII output, making integration with Arduino, ESP32, STM32, Raspberry Pi, and other compatible controllers straightforward when the required logic levels and communication settings are properly configured.
Because 24GHz radar can pass through many suitable non-metallic materials, the module can be installed behind plastic, acrylic, glass, ceramic, or similar enclosure materials. This makes it suitable for discreet installation in smart appliances, lighting systems, security devices, HVAC controls, and other embedded products.
Features
- 24GHz FMCW millimeter-wave radar sensor
- Human presence detection
- Human motion detection
- Micro-motion detection
- Suitable for breathing-related presence detection
- Motion detection distance greater than 8m under suitable conditions
- Static presence detection distance greater than 4m under suitable conditions
- Operating frequency from 23.5GHz to 24.5GHz
- 3.3V to 5V supply input
- 3.3V serial logic output
- Serial ASCII communication
- Typical operating current of approximately 80mA
- Wide horizontal and vertical detection coverage
- Can be installed behind suitable non-metallic materials
- Compact design for embedded applications
- Suitable for smart home and AIoT systems
- Useful for automation and security projects
Specifications
| Parameter | Specification |
|---|---|
| Product Type | 24GHz FMCW Human Presence Radar |
| Model | HLK-LD1125H-24G |
| Sensor Type | Millimeter-Wave FMCW Radar |
| Operating Frequency | 23.5GHz – 24.5GHz |
| Detection Mode | Human Presence, Motion & Micro-Motion |
| Static Presence Detection | Greater than 4m* |
| Motion Detection Distance | Greater than 8m* |
| Supply Voltage | 3.3V – 5V |
| Operating Current | Approximately 80mA |
| Output Interface | Serial ASCII |
| Logic Level | 3.3V Serial Logic |
| Horizontal Coverage | Approximately ±22° Half-Power Angle |
| Vertical Coverage | Approximately ±24° Half-Power Angle |
| Typical Mounting Example | Approx. 2m Coverage Radius at 3m Height* |
*Actual detection distance and coverage depend on installation conditions, target characteristics, reflections, configuration, and surrounding interference.
Working Principle
The HLK-LD1125H-24G uses FMCW (Frequency Modulated Continuous Wave) radar technology to detect changes in reflected microwave signals.
The module transmits 24GHz radar signals and analyzes the reflected signals from objects within its sensing area. Changes in the reflected signal can be used to determine whether a person or object is moving or remaining present.
Because radar can detect very small movements, the module can identify subtle body movement and breathing-related motion that may not be detected by a conventional PIR sensor.
The processed detection information is provided through the module’s serial ASCII output, allowing an external controller to use the radar status in an automation or monitoring system.
Human Presence Detection
One of the main advantages of the HLK-LD1125H-24G is its ability to detect static human presence.
A person does not necessarily have to walk through the sensing area to trigger the radar. Small movements such as breathing or minor body motion can help the system determine that a person remains within the detection area.
This makes the module useful for applications where a PIR sensor may stop detecting a stationary person after an initial movement event.
Motion and Micro-Motion Detection
The sensor can detect:
- Human movement
- Slow movement
- Small body movements
- Presence of stationary people
- Breathing-related movement
- Other suitable motion within its configured sensing zone
Detection behaviour depends on installation and configuration, so the module should be tested in the final enclosure and environment.
Serial Communication
The HLK-LD1125H-24G provides a serial ASCII output interface with 3.3V logic levels.
This allows the module to be connected to compatible controllers such as:
- Arduino
- ESP32
- ESP8266
- STM32
- Raspberry Pi
- Other 3.3V UART-compatible controllers
When connecting the module to a controller with different logic levels, appropriate level conversion should be used.
Installation and Mounting
The radar should be mounted firmly with the antenna facing the intended detection area.
For best performance:
- Keep the module stable and avoid vibration.
- Do not place metal directly in front of the antenna.
- Avoid moving fans, curtains, motors, or vibrating objects near the sensing area.
- Use suitable non-metallic materials if installing the module behind an enclosure.
- Test the module in the final installation position.
- Keep unnecessary RF or electrical interference away from the sensor where possible.
Non-Metallic Enclosure Installation
The 24GHz radar signal can pass through many suitable non-metallic materials, allowing the module to be hidden behind an enclosure or front panel.
Suitable materials may include:
- Plastic
- Acrylic
- Glass
- Ceramic
The actual sensing performance depends on material thickness, composition, surface structure, distance from the antenna, and overall enclosure design.
Typical Application Scenarios
Smart Home Presence Detection
Suitable for detecting human presence in rooms and automatically controlling lights, appliances, or other smart-home devices.
Lighting and HVAC Automation
The sensor can be used to detect occupancy and presence for automated lighting, air conditioning, ventilation, and energy-management systems.
Security Systems
Useful for presence monitoring, intrusion detection, restricted-area monitoring, and security automation.
Contactless Sensing
Suitable for applications requiring non-contact detection of human presence and subtle movement.
Industrial Monitoring
Can be used near equipment, machinery, restricted zones, and automated systems where reliable human-presence detection is required.
AIoT Projects
The module can be integrated into smart devices and embedded AIoT systems for intelligent presence and occupancy detection.
Applications
- Human presence detection
- Occupancy sensing
- Motion detection
- Micro-motion detection
- Breathing-related sensing
- Smart lighting
- HVAC automation
- Smart home systems
- Security systems
- Intrusion detection
- Industrial presence monitoring
- Office occupancy monitoring
- Contactless sensing
- AIoT projects
- Embedded automation
- Arduino radar projects
- ESP32 radar projects
- Raspberry Pi radar systems
- IoT sensor nodes
- Smart appliance development
- Ceiling-mounted presence sensing
- Enclosure-mounted radar sensing
Package Includes
- 1 × HLK-LD1125H-24G 24GHz Human Presence Radar Sensor Module
Product Disclaimer
Product images are shown for illustrative and representational purposes only. The actual module may vary slightly in PCB colour, component placement, connector design, antenna arrangement, labeling, or other visual details depending on the manufacturing batch.
Detection distance, sensitivity, coverage, and accuracy depend on installation height, mounting angle, target size, movement, environmental reflections, enclosure material, configuration, and surrounding interference.
The specified detection distances are reference values and should not be interpreted as guaranteed performance in every installation.
Important Notes
Power Supply
Use a stable 3.3V to 5V power source appropriate for the module. Ensure the power supply can provide sufficient current for stable operation.
Serial Logic
The module uses 3.3V serial logic. Take care when connecting it to controllers that use 5V logic and use appropriate level conversion where required.
Antenna Clearance
Avoid placing metal objects directly over or immediately in front of the radar antenna, as this can significantly affect detection performance.
Mechanical Stability
Secure the module firmly. Mechanical vibration or movement of the module itself can create unwanted changes in the radar signal and affect detection results.
Final Installation Testing
Always test the radar after installation in its final enclosure and mounting position because nearby walls, furniture, glass, plastic panels, fans, machines, and other objects can affect radar behaviour.
Related Radar and UWB Products
Compare this module with related radar sensors, mmWave modules and development boards available from Robosap.
- Hi-Link HLK-LD2410 24GHz Human Presence Radar Sensor Module
- Hi-Link HLK-LD2410C-P 24GHz Human Presence Radar Sensor
- Ai-Thinker RD-61 60GHz FMCW mmWave Radar Sensor Module
- Browse all Radar and UWB modules
Downloads and Documentation
Use these manufacturer or reference documents to verify specifications, wiring, communication protocol, firmware support and installation requirements before designing your system.
Documents may be updated by the manufacturer. Always confirm critical details with the latest official documentation before production use.
Frequently Asked Questions
1. What is the HLK-LD1125H-24G?
It is a 24GHz FMCW millimeter-wave radar module designed for human presence, movement, and micro-motion detection.
2. What frequency does it operate at?
The operating frequency range is 23.5GHz to 24.5GHz.
3. What is the motion detection range?
The supplied specification indicates a motion detection distance of greater than 8m under suitable conditions.
4. Can it detect a stationary person?
Yes. The module is designed to detect static human presence and small body movements such as breathing-related motion.
5. What is the static presence detection range?
The supplied specification indicates greater than 4m under suitable installation conditions.
6. What is the supply voltage?
The module supports 3.3V to 5V supply input.
7. What communication interface does it use?
It provides a serial ASCII output interface using 3.3V logic levels.
8. Can I connect it to Arduino?
Yes. It can be connected to compatible Arduino boards using the serial interface and appropriate voltage levels.
9. Can I use it with ESP32?
Yes. The ESP32's 3.3V UART logic is suitable for direct integration when the correct wiring and communication settings are used.
10. Can it work behind plastic?
Yes. The radar signal can pass through many suitable non-metallic materials such as plastic and acrylic, but material type and thickness can affect performance.
11. Can it be mounted behind glass?
It can be used behind suitable glass or other non-metallic panels, but the final installation should be tested because enclosure materials and geometry can affect sensing behaviour.
12. Is it better than a PIR sensor for stationary presence?
For applications requiring continued detection of a relatively stationary person, mmWave radar can offer an advantage because it can detect small movements such as breathing that a conventional PIR sensor may not detect.
13. What is the detection angle?
The approximate half-power antenna angles are ±22° horizontally and ±24° vertically.
14. Can it be used for smart lighting?
Yes. It can detect occupancy and presence for automatic lighting and energy-saving systems.
15. Can it be used for HVAC control?
Yes. It can be used to detect room occupancy and provide presence information to HVAC automation systems.
16. Is the module waterproof?
No waterproof rating is specified in the supplied product information. The module should therefore be protected from water and excessive moisture.
17. Does it include an enclosure or cable?
No. The package includes only the HLK-LD1125H-24G radar sensor module unless otherwise specified.
18. Can the module be hidden inside an appliance?
Yes. It can be installed behind suitable non-metallic enclosure materials, provided the final installation is tested and the antenna area remains unobstructed by metal.Downloads and Documentation
Use these manufacturer or reference documents to verify specifications, wiring, communication protocol, firmware support and installation requirements before designing your system. Documents may be updated by the manufacturer. Always confirm critical details with the latest official documentation before production use.Product Disclaimer
Images are for representation only. Actual product appearance, PCB marking, connector style, antenna layout, colour, pin-header configuration or included accessories may vary depending on the available production batch. Product description information listed here is collected from different internet sources, manufacturer pages, datasheets and reference documents, and may contain mistakes or become outdated. Always verify critical electrical, mechanical, firmware and safety details from the latest official manufacturer documentation before design, production or field installation. Radar, mmWave and UWB sensing performance depends on firmware, configuration, power supply quality, installation height, antenna direction, enclosure material, target size, target movement, reflections, interference, line-of-sight and surrounding environment. Distance, angle, accuracy and current values are reference values unless explicitly guaranteed by the latest manufacturer datasheet for the exact supplied revision.Only logged in customers who have purchased this product may leave a review.
Reviews
There are no reviews yet