1. Product Overview
The DX-SMART LR20 is a programmable, low-power, ultra-long-distance LoRa pure RF module designed for intelligent wireless data transmission. It is based on the original imported SEMTECH LLCC68 chip solution and professional R&D, offering superior performance compared to SX1278/SX1276 solutions with longer transmission distance, faster speed, and lower power consumption.
Video: DX-SMART LR20 LoRa serial communication module overview, highlighting features and package contents.
Key Features:
- Semtech LLCC68 chip + STM32F103C8T6 Chip (for development board)
- Supports LoRa® and (G)FSK modulation
- Frequency range covers 850~960MHz global Sub-GHz band (also 430-470MHz for 433Mhz variants)
- Maximum transmit power up to +22dBm
- Receiver sensitivity as low as -148dBm (LoRa® mode)
- Receive current only 4.6mA, sleep current as low as 0.7µA
- Supports SPI communication interface
- Compatible with various antenna interfaces: stamp hole/round hole and IPEX
- Visible open distance up to 8KM
- Working temperature: -40°C ~ +85°C
- Type-C charging port (on development board)
- Complete developer profile available
- Shield Protection: Antistatic & Dustproof
2. Setup and Installation
Package Contents:
The developer package typically includes a development board, a USB cable, and a glue stick antenna. The LR20-433M22S and LR20-900M22S modules use the Semtech LLCC68 chip. The LR20-433M22S module needs to be soldered, while the LR20-433M22SP development board can be used directly.
Image: LR20 Development Board and included accessories (USB cables, antennas).
Antenna Connection:
Important: The antenna must be connected before powering on the module to avoid damage from unloaded operation.
Image: Diagram showing two antenna options: U.FL Antenna Connector for external antennas and On-board Stamp Hole Antenna (default) for easier integration.
Development Board Pin Definitions:
The STM32F103-based development board provides a ready-to-use solution with a reprogrammable USB interface. Refer to the diagram below for pin assignments.
Image: Diagram of the development board hardware, showing components like the STM32F103 main control, baseboard pins, module antenna connector, power indicator, user customization buttons, and Type-C port.
Image: Detailed pinout diagram for the development board, listing pin numbers, names, functions, and descriptions.
SMD Module Pin Definitions:
For the SMD module, refer to the following pin definitions for integration into your custom PCB designs.
Image: Pinout diagram for the SMD module, detailing pin numbers, names, functions, and descriptions for connections like GND, DIO, RX, TX, VCC, MOSI, MISO, SCK, NSS, and ANT.
3. Operating Modes
The LR20 LoRa module supports various communication modes for flexible application development.
LoRa Spread Spectrum Technology:
LR20 utilizes LoRa spread spectrum technology for ultra-stable, long-range communication, offering anti-interference capabilities and stability far surpassing traditional single-frequency methods.
Image: Diagram illustrating the benefits of LoRa Spread Spectrum (anti-interference, long-range, stable) compared to single-frequency communication (interference-prone, short-range, unstable).
Supported Working Modes:
Image: Diagrams explaining three working modes: Module and module transparent transmission (requires same channel), Module and module fixed-point transmission (communicates with specified addresses and channels), and Modules and module broadcast transmission (communicates with designated channel modules).
- Module and Module Transparent Transmission: This mode requires the same channel as the sender and receiver to send data.
- Module and Module Fixed-Point Transmission: Communicate with modules with specified addresses and channels. Data transmission format (hexadecimal): receiving address + receiving channel + data.
- Modules and Module Broadcast Transmission: Communicate with designated channel modules. Data transmission format (hexadecimal): receiver channel + data.
4. Maintenance
The LR20 module is designed for industrial-grade quality, equipped with professional RF shielding to effectively block external EMI and electrostatic interference. To ensure optimal performance and longevity:
- Keep the module in a dry environment.
- Avoid exposure to extreme temperatures outside the specified operating range (-40°C to +85°C).
- Handle with care to prevent physical damage.
- Ensure proper grounding and ESD protection during handling and installation.
- Regularly check connections for secure fit.
Image: Features of industrial-grade product quality, including dustproof, -40~+85°C operating temperature, ESD protected, and EMI resistant.
5. Troubleshooting
- No Power/Module Not Responding: Verify that the power supply voltage is within the specified range (3~5.5V for development board, 1.8V~3.7V for SMD module) and connections are secure.
- No Communication: Double-check all wiring, especially for SPI interface. Ensure the antenna is properly connected before powering on. Verify frequency band settings match local regulations and the receiving module.
- Poor Range/Interference: Ensure the antenna is correctly installed and unobstructed. Check for potential sources of electromagnetic interference.
- Software Issues: Refer to the provided development environment and code examples. Ensure correct drivers are installed for the USB interface.
For complex issues or further assistance, please contact our after-sales support team.
6. Specifications
General Specifications:
| Parameter | Details |
|---|---|
| Chip Model | SMA Module: Semtech LLCC68 Chip Development Board: STM32F103C8T6 Chip |
| Module Size | SMA Module: 20*14*2.3mm Development Board: 70*30*20mm |
| Communication Protocol | LoRa protocol |
| Transmission Power | 0 ~ +22dBm |
| Frequency Band | 850-930MHz (for 900Mhz variants) 430-470MHz (for 433Mhz variants) |
| Modulation Methods | LoRa and GFSK |
| Working Voltage | SMA Module: 1.8V-3.7V Development Board: 5V |
| Sensitivity | -124dBm |
| RF Input Impedance | 50 Ω |
| Transmission Distance | Open transmission distance of 8km |
| FIFO | 256Byte |
| Hardware Interface | SPI |
| Working Temperature | -40~+85°C |
| Crystal Oscillator Frequency | 32MHz |
Image: Top and side view dimensions of the module, along with a table of key parameters.
Regional Frequency Bands:
Our LoRa solutions are globally applicable across multiple countries. However, users must verify local RF spectrum regulations prior to operation.
| Area | Frequency Band | Center Frequency |
|---|---|---|
| North America | 902-928MHz | 915MHz |
| South America | 915-928MHz | 915 MHz / 928 MHz |
| Europe | 866-915/433MHz | 433 MHz / 868 MHz / 915 MHz |
| Oceania | 915-928MHz | 915 MHz / 928 MHz |
| Asia Pacific | 915-923MHz | 920 MHz |
| South Asia | 865-867MHz | 866 MHz |
| Southeast Asia | 920-925MHz | 923 MHz |
*User must verify local RF spectrum regulations prior to operation!
Image: Table detailing global license-free ISM bands, frequency ranges, and center frequencies by region.
7. User Tips
- First-Time Users: For quick product verification, it is recommended to purchase the developer package, which includes a development board, USB cable, and antenna.
- Antenna Connection: Always connect the antenna before powering on the module to prevent damage.
- Frequency Regulations: Before operating, verify and comply with local RF spectrum regulations for your specific region.
- Development Resources: Utilize the comprehensive data package provided, which includes development environment, technical manuals, test tools, hardware information, and code examples.
8. Support and Resources
DX-SMART is a one-stop IoT solution company committed to helping you with any problems you encounter. We support OEM and ODM services.
Technical Documentation:
Professional documentation is available to help you use the module more easily and conveniently. The data package includes:
- Development Environment IDE
- Chip Technical Manual
- Module Technical Manual
- Development Board Technical Manual
- Testing Tools
- Hardware Documentation
- Code Examples
- Reference Links
Image: Visual representation of available technical documentation folders, including development environment, manuals, tools, and code examples.
Contact Information:
If you need more details or are unable to download the data package, please feel free to contact our after-sales team:
- Email: Manager@szdx-smart.com (We will respond to your question within 24 hours.)
- Website: en.szdx-smart.com
Certifications:
Our products meet global certification standards, including CE, FCC, RoHS, and ISO.
