1. Introduction
The DX-LR32 LoRa Module, powered by the SEMTECH SX1262 chip, is designed for long-range, ultra-low power IoT communication. It supports various frequency bands including 433/475/868/915MHz and offers a communication range of up to 5 kilometers in open areas. This module is ideal for applications such as smart metering, smart city infrastructure, and smart agriculture.
The module operates via a UART TTL interface and supports AT commands for code-free development, making it versatile for various embedded projects.
2. Specifications
| Parameter | Value |
|---|---|
| Core Chip | SEMTECH SX1262 |
| Operation Interface | UART TTL interface (supports AT commands) |
| Frequency Bands | 433-532MHz, 850-949MHz |
| Communication Range | Up to 5 km (open areas) |
| Power Consumption (Sleep) | As low as 3.28µA |
| Transmit Power | 0~22dBm |
| Supply Voltage | 3.3-5.5 V |
| Receiver Sensitivity | -138dBm |
| Module Size | 36 x 16.5 mm |
| Data Buffer | Built-in 230-byte |
| Working Temperature | -40~+85 °C |
| Modulation Methods | LoRa |
3. Setup and Installation
Before powering on the module, ensure all connections are secure, especially the antenna.
3.1 Module Pin Definitions
| Pin Number | Pin Name | Pin Function | Description |
|---|---|---|---|
| 1 | M0 | Reserved, customizable IO port | M0 and M1 work together to determine the module's four operating modes. Refer to the datasheet for details. |
| 2 | M1 | Reserved, customizable IO port | M0 and M1 work together to determine the module's four operating modes. Refer to the datasheet for details. |
| 3 | UART_RX | UART RX | Serial Port Data Input |
| 4 | UART_TX | UART TX | Serial Port Data Output |
| 5 | AUX | Module RF Status Indicator Pin | Refer to the datasheet for details |
| 6 | VCC | Power Input Pin | 3.3V-5.5V (Typical) |
| 7 | GND | Ground | Power Ground |
Important: Connect the antenna before powering on the module to avoid unloaded operation and potential damage.
3.2 Antenna Options
The module supports dual antenna options: U.FL antenna connector and an on-board Stamp Hole Antenna (default).
- U.FL Antenna Connector: Uses external antenna for extended range, ideal for complex environments.
- On-board Stamp Hole Antenna (Default): Built-in antenna for easier integration, suitable for most applications.
3.3 Adapter Board (PJ15)
The PJ15 adapter board facilitates connection and development. Its pin definitions are as follows:
The distance between the two rows of needles on the module is 2.54mm.
4. Operating Instructions
The DX-LR32 module operates using standard UART serial communication and is controlled via AT commands.
4.1 Working Modes
The module supports two primary working modes: Fixed-point transmission and Broadcast transmission.
4.1.1 Fixed-point Transmission
In fixed-point transmission, communication is established if the target address and target channel within the data match those of the receiver, and both sender and receiver share the same data rate level. The data format is: Destination Address + Destination Channel + Data.
4.1.2 Broadcast Transmission
When the sender transmits data, the target channel within the data must match the receiver's channel, and both sender and receiver must operate at the same rate level to establish communication. Data format example: Target channel + Data.
Note: This module supports only standard UART serial communication; it does not support LoRaWAN or Meshtastic. For LoRaWAN or Meshtastic applications, please contact our professional advice team.
4.2 AT Commands
The module is configured and controlled using AT commands. A comprehensive list of commands and their functions is provided in the technical documentation.
| No. | Instruction | Function |
|---|---|---|
| 1 | AT+LEVEL | Set/Query Module Air Rate and Communication Distance |
| 2 | AT+OPENKEY | Set/Query Module Key Switch |
| 3 | AT+KEY | Set Module Key |
| 4 | AT+LBT | Set/Query LBT Status |
| 5 | AT+LRSSI | Set/Query LBT Listening Threshold |
4.3 Indicator Status
- Working status: Red light blinking
- Hibernation mode: Light off when hibernating
- Wake-up: Red light flashing when waking up
4.4 Built-in Secure Encryption
The LR31/LR32 modules are equipped with a customizable communication key function. Users can set a unique security key to encrypt data transmitted over the air. This key is non-retrievable, effectively preventing data leakage and ensuring communication security.
4.5 Product Overview Video
5. Maintenance
To ensure the longevity and optimal performance of your DX-LR32 LoRa module, follow these maintenance guidelines:
- Environmental Conditions: Store and operate the module within the specified temperature range of -40°C to +85°C. Avoid exposure to extreme humidity, dust, or corrosive substances.
- Antenna Connection: Always ensure the antenna is securely connected before applying power to the module. Operating without an antenna can damage the RF output stage.
- Power Supply: Use a stable power supply within the 3.3V to 5.5V range. Over-voltage can permanently damage the module.
- Cleaning: If necessary, gently clean the module with a dry, soft cloth. Avoid using liquids or abrasive cleaners.
- Handling: Handle the module with care to prevent physical damage to components or pins.
6. Troubleshooting
This section provides solutions to common issues you might encounter with your LoRa module.
6.1 No Data Transmission/Reception
- Check Antenna: Verify that the antenna is correctly and securely attached. An improperly connected antenna can severely degrade performance or prevent communication entirely.
- Power Supply: Ensure the module is receiving stable power within the 3.3V-5.5V range.
- UART Connection: Double-check the RX/TX connections to your microcontroller or host device. Ensure baud rates match.
- Working Mode Configuration: Confirm that both the transmitting and receiving modules are configured for the same working mode (Fixed-point or Broadcast) and channel.
- AT Commands: Verify that the correct AT commands are being sent and acknowledged. Use the AT+LEVEL command to check air rate and communication distance settings.
- Signal Strength (RSSI): Utilize the RSSI (Real-Time Signal Strength Indicator) feature to assess wireless signal quality and strength. Poor RSSI can indicate range issues or interference.
6.2 Module Not Responding
- Power Cycle: Try power cycling the module.
- Reset Pin: If available, use the RST pin to reset the module.
- Check Wiring: Ensure all power and data lines are correctly wired and free from shorts or breaks.
6.3 Unexpected Behavior
- Interference: LoRa modules can be susceptible to interference from other RF devices. Try operating in a different location or adjusting frequency settings if possible.
- Firmware: Ensure you are using the latest stable firmware for your module.
If you continue to experience issues, please refer to the comprehensive technical documentation or contact support.
7. User Tips
- Frequency Selection: Always select the appropriate frequency band (433/475/868/915MHz) for your region to comply with local regulations and optimize performance.
- Antenna Placement: For best range and signal quality, ensure your antenna has a clear line of sight and is positioned away from obstructions.
- Power Management: Leverage the module's ultra-low sleep current for battery-powered applications to maximize battery life.
- Security: Utilize the built-in secure encryption feature to protect your data transmissions, especially in sensitive IoT applications.
- Documentation: The provided technical manual, application guides, and video tutorials are invaluable resources for advanced configuration and troubleshooting.
8. Support and Resources
For further assistance, technical documentation, and resources, please refer to the following:
- Technical Documentation: Comprehensive documentation, Arduino sample projects, source code examples, and video tutorials are available.
- Download Links:
- DX-LR31&32-433T22D: Google Drive Folder
- DX-LR32&32-900T22D: Google Drive Folder
- Customer Support: If you are unable to download materials or have further questions, please contact our after-sales team. We aim to respond within 24 hours.
Email: Manager@szdx-smart.com
8.1 Certifications
The DX-LR32 module meets global certification standards, including CE, FC, RoHS, and ISO, ensuring quality and compliance.
