Wireless SX1276 LoRa Module, 868MHz and 915MHz, 3.3V, SMA Connector

Description

Please note we can not accept returns for this board if you order the wrong board, and order it with pin headers soldered! So, please ensure to order to correct version and frequency from our inAir range of LoRa boards.

The inAir9 is a 868 and 915Mhz wireless module using the Semtech SX1276 chip, with a standard SMA connector (for antenna). It is part of our iMod product range. The frequency is configured in software, and will typically be used for the 863-870MHz or 902-928MHz ISM bands. This module is nearly identical to the inAir9B, except that is has a maximum output power of +14dBm, where the inAir9B has a maximum of +20dBm. This modules requires less supply current than the inAir9B, even when configured for the same output power (+14dBm or less). Choose this module if power consumption has to be kept to a minimum, and no more than +14dBm is required.

The SX1276 is a revolutionary new chip enabling wireless communications at distances up to 15km, using Semtech's LoRa(Long Range) technology. This chip also supports high performance (G)FSK modes for systems including WMBus, IEEE802.15.4g.

This module can be used for 868 and 915MHz communication. It is based on the Semtech SX1276RF1KAS and SX1276RF1IAS reference designs, which also use identical components for 868 and 915MHz. We have also confirmed with Semtech engineers that there reference design is correct, and both modules have identical components.

The board is a high quality, RF optimized, 4 layer PCB. It has been designed with assistance from Semtech engineers, ensuring optimum layout and performance! Only brand name, high quality components are used! All capacitors and inductors are high precision parts, resulting in optimized performance. The crystal a very critical component for the SX1276, and is required to be very accurate to achieve high sensitivity. This board uses a high accuracy crystal as recommended by Semtech.

This module will outperform competitor products that use 2 layer PCBs, cheap capacitors and inductors and low accuracy crystals! When choosing a SX1276 module, it is very important to realize that they will NOT all perform the same just because they use the same chip! Designing RF boards is very tricky, and lots of power and sensitivity is lost due to bad PCB design and poor components!

This module enables 3.3V devices (like a Microcontroller for example) to communicate with remote nodes via a wireless protocol.For details on the SX1276 chip, download it's datasheet from www.semtech.com.

This board has a metal shield for improved performance.

A SMA Edge connector (CON-SMA-FE16-RG) is mounted on this board. It can however also be assembled with a U.FL connector. Two standard 1x7, 2.54mm (0.1") pin header (or press-fit headers) can be soldered onto this board (position X1 and X2 on board). If required, wires can of course be soldered onto the PCB in stead of pin headers. If required, this module can also be used as a SX1276 breakout board, and wires can be soldered onto the PCB in stead of pin headers.

 

Bottom View	Top view (without SMA connector)	Dimensions	Schematics (pdf format)
Click to enlarge

Features

• Wide Operating voltage from 1.8V to 3.7V
• 153 dB maximum link budget
• +14 dBm high efficiency PA
• Programmable bit rate up to 300 kbps
• High sensitivity: down to -139 dBm (-148 only possible with TCXO)
• Bullet-proof front end: IIP3 = -11 dBm
• Excellent blocking immunity
• Low RX current of 9.9 mA, 200 nA register retention
• Fully integrated synthesizer with a resolution of 61 Hz
• FSK, GFSK, MSK, GMSK, LoRaTMand 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
• High quality assembly, with brand name, quality components. No cheap, “no name brand” components are used!
• Module dimension: 27.3mm x 24.51mm (1.075" x 0.965")
• RoHS Compliant
• Operating Temperature -40°C to + 85°C

Details

Solder Jumper J1 & RF Switch

Note that solder jumper J1 at the back of the board has to be made to apply power to the RF Switch. Making jumper J1 applies permanent 3.3V power to the RF Switch (U5 in schematic = PE4259).

If solder jumper J1 is not made, power for the RF switch is supplied via iMod port pin 10, marked VS on PCB. This is useful for very low power applications that want to save the 9 to 20uA supply current required by the RF switch. For these applications, power can be supplied(to iMod port pin 10) via a port pin on CPU only when transmitting or receiving.

• Option 1 to power RF Switch:
  Make solder jumper J1 on back of board.
• Option 2 to power RF Switch:
  Ensure solder jumper J1 is NOT made. RF switch can now be powered on/off by applying 3.3V to iMod port pin 10 (marked VS on PCB).

Pin Headers

Documentation

	Web	PDF	Data
inAir9 Datasheet and Schematics
sx1276/sx1278 Datasheet

Expansion & Software

The inAir9 module can be used with virtually any Microcontroller that has a SPI port, some free I/Os, and operates at 1.8-3.3V.

For links to example code for Arduino, mbed and Raspberry Pi, click here.

STM32 Microcontrollers

Our NZ32 STM32 Microcontroller boards can be used together with the inAir9 module. The NZ32-SC151 boards is assembled with the STM32L151RC microcontroller (compatible with other STM32L151 and STM32L152 chips). It has a Lithium Polymer battery charger, 3.3V DC/DC regulator, high speed and RTC crystal, LEDs, buttons and circuitry for doing various analog measurements. This board will be followed by alternative versions assembled with the STM32F030R8T6 (low cost), STM32F205RCT6 and STM32F411RCT6 microcontrollers.

mbed Platform

A SX1276 API, and various example projects are available on the mbed.org developer site (search site for SX1276). We will also be providing an example project for our STM32 board mentioned above, and the inAir9.

LoRaWAN and LoRaMAC

This board can be used together with the STM32 board mentioned above to implement the LoRa WAN protocol. The code is available for free from IBM, just do an internet search for "LoRa WAN in C". At the time of writing this, it was available here.

There is also additional code available on GitHub, to see it click here.

Other

Semtech recently announced that Microchip Technology Inc. adopted Semtech’s long-range LoRa™ RF technology. We still have to perform tests, but it is possible that these modules will be compatible with Microchip's example code. Special versions of this board using Microchip LoRa chips can also be assembled on request (once these chips become available).

What is included

• 1 x iMod module, all surface mount components fully assembled, as shown in picture above. The pin headers and terminal block connector are not assembled!