Low-cost LoRa Module

Introduction

This is low-cost LoRa gateway module which is powered by RFM96-low power long range transceiver module. The gateway can receive from any LoRa device and is designed to be fully customizable for a targeted application.Various applications are considered: water quality monitoring, cattle rustling, logistics and goods transportation.

This LoRa gateway could be qualified as "single connection" as it uses the SX1272, much like an end-device would do. However, in order to increase LoRa transmission robustness we improve the LoRa transmission with CSMA features (or so-called Listen Before Talk) and add Quality of Service guarantees with regards to radio time limitations.

Feature

• LoRa Modem.
• 168 dB maximum link budget.
• +20 dBm - 100 mW constant RF output vs. V supply.
• +14 dBm high efficiency PA.
• Programmable bit rate up to 300 kbps.
• High sensitivity: down to -148 dBm.
• Bullet-proof front end: IIP3 = -12.5 dBm.
• Excellent blocking immunity.
• Low RX current of 10.3 mA, 200 nA register retention.
• Fully integrated synthesizer with a resolution of 61 Hz.
• FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation.
• Built-in bit synchronizer for clock recovery.
• Preamble detection.
• 127 dB Dynamic Range RSSI.
• Automatic RF Sense and CAD with ultra-fast AFC.
• Packet engine up to 256 bytes with CRC.
• Built-in temperature sensor and low battery indicator.

Tutorials

Prerequisites

Hardware

• Arduino UNO x 2
• Linker LoRa Radio x 2
• Linker Base Shield x 2
• 4 Pin DuPont line x 4

Software

• Click here to download the Arduino project.
• Put the files in src folder which contains SX1272 libraries and examples into the directory of the Arduino IDE's libraries.

Hardware assemble

• According to the following picture, connect LoRa module and Arduino Uno Note: One is used to be LoRa gateway, and other one is used to be LoRa end device, they take same connections.

LoRa Gateway

• Open Arduino IDE
• Open File --> Examples --> SX1272 --> Arduino_LoRa_Gateway
• Upload code to Arduino Uno Note: Please select the right serial port and board type.

• Open the Arduino IDE Serial Monitor
• Set the baudrate as 38400

Check communication

• Open the two serial Monitor, one for LoRa_gateway and one for LoRa end device
• Restart both devices, then you can see them starting to communicate.

Schematic