Wireless LoRa Module SX1278 (SX1276), 433MHz

The inAir4 is a 433Mhz wireless module using the Semtech SX1278(or SX1276) chip, with a standard SMA connector (for antenna). The frequency is configured in software, and will typically be used for the 430 to 435MHz ISM band(contry dependant). It is part of our iMod product range. The SX1278 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.

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).

Documentation

	Web	PDF	Data
inAir4 Datasheet and Schematics
sx1276/sx1278 Datasheet

Expansion & Software

The inAir4 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.

mbed Platform

A SX1274 API, and various example projects are available on the mbed.org developer site (search site for SX1276 or SX1278). We will also soon be providing an example project for our STM32 board mentioned above.

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.

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!