1. Introduction
The HLK-LD2411S is a motion/micro-motion human sensing range sensor module from the Halingco radar family. It integrates highly simplified 24 GHz radar sensor hardware and intelligent algorithm firmware RM01. The working principle utilizes FMCW (Frequency Modulated Continuous Wave) to detect targets within a set space. Combined with radar signal processing and an accurate induction algorithm, it provides precise induction of micro-moving object distance and status information.
The LD2411S hardware comprises a 24 GHz millimeter wave radar chip, a high-performance transmit-and-receive microstrip antenna, a low-cost MCU, and peripheral auxiliary circuits. Users can adjust the module's placement direction according to the actual application scenario. The smart algorithm firmware RM01 employs FMCW waveform and S3 series chip's proprietary advanced signal processing technology to achieve accurate human body distance measurement and motion/micro-motion body sensing.
2. Product Features
- 24 GHz ISM band operation.
- Integrated intelligent millimeter wave radar single chip and intelligent algorithm firmware.
- Accurate indoor/outdoor human motion/micro-motion sensing and distance detection.
- 5V single power supply.
- Continuous operating average current of 48mA at 20 Hz update frequency.
- Provides a visualization tool to support configuration of detection distance intervals and sensitivity settings by distance gate.
- Human body sensing up to 6m.
- Micro-motion human body sensing up to 3.5m.
- High precision distance measurement: 30~350cm (±5cm); 350~600cm (±5%).
- Azimuth +20°, Pitch +45°.
3. Application Scenarios
The LD2411S motion/micro-motion human sensor can detect and identify motion and micro-motion of the human body, reporting real-time distance. It is widely used in various AIoT scenarios, including:
- Smart Home: Sensing human motion/micro-movement and distance, reporting detection results for intelligent control of home appliances by a master control module.
- Smart Commercial: Applications such as sensor-activated doors and escalators.
- Smart Lighting: Integration into induction access control systems, building intercoms, and electronic cat's eyes.
- Intelligent Security: Used in induction access control, building intercoms, and electronic cat's eyes for enhanced security.
4. Specifications
| Attribute | Value |
|---|---|
| Model Number | HLK-LD2411S |
| Communication method | Other (TTL serial port transmission) |
| Camera Equipped | No |
| Compatibility | Others |
| Brand Name | bibikoo |
| Origin | Mainland China |
| Voltage | 5V |
| Current | 50mA |
| Longest distance of human body induction | 6m |
| Farthest distance of micro-action human body sensing | 3.5m |
| Size | 27.5*27.5mm |
- 1: VIN, 5V Input power
- 2: GND, Power ground
- 3: OUT, Induction output high level
- 4: TXD, serial port sending/IO
- 5: RXD, Serial port receiving/IO
5. Setup and Operation
5.1. Connecting to the Host Computer
To configure and monitor the HLK-LD2411S module, you will need to connect it to a host computer using a serial port interface. The module supports TTL serial port transmission.
5.2. Configuration Steps
- Step 1: Open Software and Connect Device
Open the provided host computer software. The software interface will appear as shown in Figure 4. Click the "Refresh" button on the interface, then select the corresponding serial number of the radar module and enter the correct baud rate. Click "Connect Device". Upon successful connection, the button text will change to "Disconnect Device", and the firmware version number of the radar module will be displayed under "Firmware Version".
Figure 4: Host computer software interface (showing serial port selection, baud rate, and connection status) - Step 2: Parameter Configuration
Click the "Parameter Configuration" button. A parameter configuration interface will pop up, as shown in Figure 5. Here, you can edit the parameter values according to your specific needs. After making changes, click the "Set Parameters" button to send the updated parameters to the radar module. The software will then return to the main interface. Refer to the communication protocol documentation (if provided separately) for detailed explanations of each parameter.
Figure 5: Parameter configuration interface (showing settings for motion range, idle time, and distance compensation) - Step 3: Real-time Data Reception
Click the "Start" button on the main interface to begin receiving real-time data from the radar module. The host computer interface will display the distance and status of the detected target. A distance curve showing the target human body's distance from the radar module over the last 15 seconds will also be displayed at the bottom of the interface.
Figure 6: Host computer real-time data display (showing detected distance and status, with a distance curve) - Step 4: Stop Data Transmission
To stop data transmission between the radar module and the host computer, click the "Stop" button. All data from this test session can be viewed in the Log folder located within the host computer software's directory.
6. User Tips
- The compact size of 27.5x27.5mm makes this module suitable for integration into various space-constrained projects.
- Leverage the long human body induction distance (up to 6m) for applications requiring wide area coverage, such as smart lighting or security systems.
- For precise detection of subtle movements, utilize the micro-motion sensing capability up to 3.5m.
- Always ensure the correct serial port and baud rate are selected in the host computer software for stable communication.
- Experiment with parameter configurations to optimize detection distance and sensitivity for your specific environment and application.
7. Troubleshooting
- No Data Output:
- Verify that the module is correctly powered (5V).
- Check serial port connections (TXD, RXD, GND) for proper wiring.
- Ensure the correct serial port (COM port) and baud rate are selected in the host computer software.
- Confirm the "Connect Device" button shows "Disconnect Device", indicating a successful connection.
- Inaccurate Readings:
- Review the parameter configuration in the host computer software. Adjust detection distance intervals and sensitivity settings.
- Ensure the module's placement direction is appropriate for the detection area and free from obstructions.
- Minimize environmental interference (e.g., large moving objects outside the detection zone, strong electromagnetic fields).
- Module Not Responding:
- Disconnect and reconnect the module's power supply.
- Restart the host computer software.
- Check for any physical damage to the module or connecting cables.
8. Maintenance
- Cleaning: Keep the module clean and free from dust and debris. Use a soft, dry cloth for cleaning. Avoid using liquids or abrasive cleaners.
- Environment: Operate the module within its specified environmental conditions (temperature, humidity) to ensure optimal performance and longevity.
- Firmware Updates: Periodically check the manufacturer's website for any available firmware updates to improve performance or add new features.
- Storage: When not in use, store the module in a dry, anti-static environment to prevent damage.
9. Warranty and Support
For technical support, warranty claims, or further inquiries regarding the HLK-LD2411S module, please contact the manufacturer or your authorized reseller. Ensure you have your purchase details and model number available when seeking support.
Manufacturer: Shenzhen Hi-Link Electronic Co., Ltd
