SX1272 Based LoRa USB Dongle Gateway 868/915MHz

Overview

In this guide, we will learn about the SX1272 Based LoRa USB Dongle Gateway. The LoRa USB Dongle is a low-cost RF front-end transceiver module with high sensitivity of -137dBm and a power output of 20dBm which makes the module suitable for low-range and low-data rate applications.

The Dongle has direct use of USB interface control & does not need to understand the complex transmission LORA concept. It can also be directly connected with the Raspberry Pi to make an IoT LoRa gateway with fewer software setups.

This tutorial covers the basic usage of LoRa USB Dongle with the Application software. One of the LoRa USB Dongle can be used as a transmitter Module and the other as a Receiver Module. Any message can be sent or received in text, Hex, or decimal format.

iFroglab LoRa USB Dongle Gateway

These are the pair of LoRa USB Dongles based on the SX1272 LoRa chip. The product is made in Taiwan & designed by ifroglab and sold ON TechDesign. website

The product doesn’t require any external components and has a direct USB interface. Hence this product can be directly connected to your Computer USB or Raspberry Pi Pico. According to the datasheet, the transmission distance it can achieve is 15km but in my normal testing the distance it achieved was almost 3km.

The product can be directly connected to the Raspberry Pi Board and can be used as an IoT LoRa gateway. The product works on 868/900/915MHz frequency. Hence it can be used globally for multipurpose applications.

The circuit board inside the plastic package is designed using SX1272 LoRa Module.

LORA1272 is a type of low-cost RF front-end transceiver module based on SX1272 from Semtech Corporation. It keeps the advantages of RFIC SX1272 but simplifies the circuit design. The high sensitivity (-137dBm) in LoRa modulation and 20dBm high power output make the module suitable for low-range and low-data rate applications.

LORA1272 module consists of RFIC SX1272 and includes powerful MCU, thin SMD crystal, and antenna matching circuit. The antenna port is well matched to the standard 50 Ohm impedance. Users don’t need to spend time in RF circuit design and choose suitable antennas for different applications. LORA1272 operates at 1.8~3.6V with an extra low standby current which makes it suitable for battery-powered-up applications. Because LORA1272 is purely a hardware module and it adopts ±10ppm crystal resolution and plays an important role in calculating spreading factor, bandwidth, etc.

iFroglab LoRa module has the integration of two chips on the Module board. One is ASIC MCU that controls SX1272 thru the SPI interface and gets AT command from UART transport.

Download: AT Command Table

To learn about the two way LoRa communication please check LR1276/SX1276 LoRa Communication guide.

Features of SX1272 based LoRa USB Dongle

Frequency Range: 868/900/915MHz
Modulation: FSK/GFSK/MSK/LoRa
LoRa gateway
High RX Sensitivity: -137dBm
Output Power: +20dBm Data Rate: <300 kbps 127dB dynamic Range RSSI Excellent blocking immunity Preamble detection Automatic RF sense and CAD monitor Built-in bit synchronizer for clock recovery Packet engine up to 256 bytes with CRC
Working Temperature: -40°C ~+80°C Build-in temperature sensor
Standby current: ≤ 1uA
Supply voltage: 5 V for USB
Has Complete sample code for such LoRa gateway https://github.com/iFrogLab/IL-LORA1272
Supported Sleep mode, capable to provide real low power mode for Green Power application.

Setup/Usage & Communication using iFrogLab LoRaApp

First connect both LoRa USB Dongle to two different USB Ports and identify the Port number using the Device Manager of your computer.

The second thing that we need is to download the iFrogLab LoRa Application. The file is an executable file and can be directly run without any installation.

Download: iFrogLab LoRa APP

Once you run the file, you will have two options. Here we need to select the “iFrogLab LoRa App“.

A Window will open where all the operations related to LoRa transmission and receiving can be performed.

You need to open this pair of Windows as one window will be for transmission and the other for receiving.

From the COM Port Option, Select the respective COM port. In my case, LoRa attached to COM port 9 is the Transmitter and the LoRa attached to COM port 10 is the Receiver.

In the ‘Setup Device‘ Part Select ‘Broadcast‘ and then Click on ‘Open LoRa‘. The App will now establish communication with & between both LoRa USB Dongle.

In the Send data part select the format in which you want to transmit data. The available format is Text, Decimal & Hexadecimal. On the other Window in the ‘Receive Data’ Section, select the format in which you want to Receive Data. The sender and receiver of both formats should be the same.

Now you can start sending and receiving the data in the format you want. Therefore type some message and hit the Send button to Send the message.

The message will be received on the other Window by the 2nd USB Dongle via LoRa Wireless Communication.

This is how you can do a simple two-way communication between a pair of SX1272 Based LoRa USB Dongle Gateway. There is a lot to know about other means of communication and using this dongle as a Gateway. Resources are available below, you can refer them for more information.