1. Introduction
The HLK-LD2415H is a sophisticated 24G millimeter wave radar module designed for precise vehicle speed measurement. It integrates a microstrip antenna, radio frequency circuit, and signal processing circuit, enabling it to directly output target speed information.
Capable of long-distance car speed detection up to 180 meters or more, this module features an integrated radio frequency chip for extremely high frequency stability and a speed measurement accuracy of 1 KM/h. Its robust design makes it suitable for various applications, including speed reminders on highways, urban trunk lines, city and county highways, urban and rural trunk roads, as well as road curve and intersection warnings.
2. Specifications
The following table details the main technical parameters of the HLK-LD2415H radar module:
| Parameter | Value |
|---|---|
| Model Number | HLK-LD2415H |
| Origin | Mainland China |
| Working Frequency | 24.125GHz (Customizable) |
| Operating Voltage (VCC) | 9V ~ 24V |
| Operating Current (ICC) | ≤50mA @ 12V |
| Modulation Method | CW (Continuous Wave) detects moving vehicles |
| Interfaces | RS485 / TTL Serial Port (Baud rate 9600bps) |
| Speed Measurement Range | 1 KM/H ~ 240 KM/H |
| Speed Measurement Error | Less than ±1 KM/H (at zero degrees angle to radar beam) |
| Output Power (EIRP) | 20dBm |
| Actual Power Consumption | ≤1.2W |
| Antenna Angle (3dB beam width) | Horizontal 40°, Pitch 16° (Actual detection angle covers >4 lanes) |
| Dimensions (L*W*H) | 69mm * 53mm * 5mm |
| Operating Temperature | -20°C ~ +85°C |
| Storage Temperature | -40°C ~ +125°C |
3. Components
The standard package includes the HLK-LD2415H radar module. A kit version may also be available, which typically includes:
- HLK-LD2415H Radar Module
- 1.25 to 2.54mm 8-Pin Dupont Terminal Wires (for easy connection)
4. Setup and Wiring
Proper wiring is crucial for the correct operation of the HLK-LD2415H module. Refer to the interface diagram and pin description table below for connection details.
J4 Interface Pin Description:
| Serial Number | Pin Name | Description |
|---|---|---|
| 1 | Pin1 (PULSE) | PULSE (High-level active output signal version: a high-level active output pin) |
| 2 | Pin2 (AA) | AA (Active low output signal version: active low output pin) |
| 3 | UART_RX | Receive data for TTL serial communication |
| 4 | UART_TX | Transmit data for TTL serial communication |
| 5 | B | 485 serial port data B |
| 6 | A | 485 serial port data A |
| 7 | GND | Power ground |
| 8 | VCC | 9~24V Power supply input |
4.1 Power Supply
Connect the VCC pin to a stable power source within the 9V to 24V range. Connect the GND pin to the power ground. Ensure the power supply can provide at least 50mA at 12V.
4.2 Communication Interface
The module supports two communication interfaces:
- TTL Serial Port: Use UART_RX and UART_TX pins for serial communication with a microcontroller or other serial devices. The baud rate is fixed at 9600bps.
- RS485 Interface: Use pins A and B for RS485 differential communication, suitable for longer distances and noisy environments.
4.3 Output Signals
- PULSE (Pin1): This pin provides a high-level active output signal, indicating detection or other status depending on the module's configuration.
- AA (Pin2): This pin provides an active low output signal, also for detection or status indication.
5. Operation
Once powered and correctly wired, the HLK-LD2415H module operates by continuously emitting 24.125GHz CW (Continuous Wave) microwave signals. When a moving vehicle enters its detection range (up to 180 meters), the module processes the reflected signals to determine the vehicle's speed.
The calculated speed information is then output directly via the configured communication interface (RS485 or TTL serial port). Users can read this data using a compatible device (e.g., microcontroller, PC with serial adapter) at a baud rate of 9600bps.
The module is designed for automatic detection and speed feedback, requiring minimal configuration for standard operation. Specific data protocols for serial communication would typically be provided in a separate software development kit (SDK) or detailed protocol document.
6. Maintenance
The HLK-LD2415H module is designed for robust and reliable operation with minimal maintenance. To ensure its longevity and optimal performance:
- Environmental Conditions: Operate and store the module within the specified temperature ranges (-20°C to +85°C operating, -40°C to +125°C storage). Avoid exposure to extreme humidity, corrosive substances, or strong vibrations.
- Cleaning: Keep the module's surface, especially the antenna area, clean and free from dust or debris. Use a soft, dry cloth for cleaning. Do not use harsh chemicals or abrasive materials.
- Handling: Handle the module with care to prevent physical damage. Avoid applying excessive force to the connectors or the PCB.
- Power Supply: Ensure a stable and clean power supply within the specified voltage range (9-24V) to prevent damage from voltage fluctuations.
7. Troubleshooting
If you encounter issues with your HLK-LD2415H module, consider the following troubleshooting steps:
7.1 No Power / Module Not Responding
- Check Power Connections: Verify that VCC and GND are correctly connected and that the power supply is providing the specified voltage (9-24V) and sufficient current (at least 50mA).
- Inspect Wiring: Ensure all power and communication wires are securely connected and free from damage.
7.2 No Speed Data Output
- Verify Communication Setup: Double-check that your receiving device (e.g., microcontroller, PC) is configured for the correct interface (TTL or RS485) and baud rate (9600bps).
- Check RX/TX Lines: For TTL serial, ensure UART_RX of the module is connected to TX of your device, and UART_TX of the module is connected to RX of your device.
- RS485 Polarity: For RS485, ensure A and B lines are not swapped.
- Target Presence: Confirm that a moving vehicle is within the detection range (up to 180m) and within the antenna's beam angle.
7.3 Incorrect or Inconsistent Speed Readings
- Module Orientation: Ensure the module is oriented correctly towards the direction of vehicle movement. The most accurate readings are obtained when the angle between the movement direction and the radar beam azimuth is close to zero degrees.
- Interference: Check for potential sources of electromagnetic interference (EMI) near the module that could affect radar performance.
- Obstructions: Ensure there are no physical obstructions (e.g., dense foliage, large metal objects) blocking the radar's line of sight to the target.
- Power Stability: Unstable power can sometimes lead to erratic readings. Verify power supply stability.
8. User Tips
No specific user tips were available from provided reviews or Q&A content. For best performance, ensure the module is mounted securely and has a clear line of sight to the target area.
9. Warranty and Support
For warranty information, technical support, or further inquiries regarding the HLK-LD2415H module, please contact Shenzhen Hi-Link IoT Module Store directly or refer to the official Hi-Link website. Keep your purchase records for any warranty claims.
