This Wiki page contains additional information for the following Modtronix SX1276/SX1278 LoRa Radio boards:
See important configuration information in configuration section below! The inAir range of boards are 433Mhz, 868Mhz and 915Mhz wireless module using the Semtech SX1276/SX1278 chips. They are available with a SMA or U.FL antenna connectors. They are part of our iMod product range.
The inAir4 board has a fixed frequency of 433MHz.
The inAir9 and inAir9B boards are configured in software for the 868Mhz or 915Mhz band, and will typically be used for the 863-870MHz or 902-928MHz ISM bands. These modules 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. Many radio modules require different components for 868Mhz and 915Mhz versions, but the SX1276 based modules have identical components.
The inAir9 and inAir9B modules are nearly identical, except that the inAir9 has a maximum output power of +14dBm, where the inAir9B has a maximum of +20dBm. The inAir9 requires less supply current than the inAir9B, even when configured for the same output power (+14dBm or less). Choose the inAir9 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.
These modules use high quality, RF optimized, 4 layer PCBs. They have 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 is a very critical component for the SX1276/SX1278, and is required to be very accurate to achieve high sensitivity. This board uses a high accuracy crystal as recommended by Semtech.
These modules 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!
These modules 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.
These boards are available with an SMA Edge, or U.FL antenna connector. Two standard 1×7, 2.54mm (0.1“) pin header (or press-fit headers) can be soldered onto these boards (position X1 and X2 on board). If required, wires can of course be soldered onto the PCB in stead of pin headers. These modules can also be used as a SX1276 breakout board, and wires can be soldered onto the PCB in stead of pin headers.
For inAir4 and inAir9 only (SMA and U.FL versions)
For inAir9B +20dBm high power module only (SMA and U.FL versions)
For all inAir boards
Currently our inAir modules are available in SMA and U.FL versions.
The following versions have a SMA connector(female version), and can be used with antennas fitted with SMA connectors(with male pin inside connector):
The following versions have an SMA connector, and can be used with antennas fitted with SMA connectors:
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.
The inAir4, inAir9 and inAir9B all have the same dimensions. Click to enlarge:
Below are the schematics for the inAir4, inAir9 and inAir9B modules. Click to enlarge:
The Datasheet for the “SX1276/SX1278” chip used on this board can be downloaded here.
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.
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.
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.
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.
This module is designed and manufactured by Modtronix! Only high quality components from reputable suppliers are used! All components have been selected to exceed the maximum rated specifications. The following components are used:
This module can be supplied with pin headers. The following options are available.
No pin header is assembled or included with the board.
Two unsoldered(loose) Pin Headers are supplied with the board for free. The pin(mating) length is 3.0, 4.0 or 6.0mm. The number of pins depends on the iMod board. For most boards two 1×6 pin headers are supplied.
Pin headers with 3.0mm long pins are assembled. Select this option if the module is going to be soldered into place. The picture on the right shows an example of an iMod module soldered onto a main board.
Header size (2 to 8 pin) depends on iMod board. Many boards will get a 2 pin header on one side, and a 4 or 5 pin on the other. For details on these pin headers, see 3.0mm pin headers on our site.
Pin headers with 4.0mm long pins are assembled. Select this option if the module is going to be plugged into a low profile 5.7mm high female socket (2.54mm grid).
Header size (2 to 8 pin) depends on iMod board. Many boards will get a 2 pin header on one side, and a 4 or 5 pin on the other. For details on these pin headers, see 4.0mm pin headers on our site.
Pin headers with 6.0mm long pins are assembled. Select this option if the module is going to be plugged into a standard 2.54mm female socket.
Header size (2 to 8 pins) depends on iMod board. Many boards will get a 2 pin header on one side, and a 4 or 5 pin on the other. For details on these pin headers, see 6.0mm pin headers on our site.
Two 6 Pin headers with Round (Swiss) style pins are assembled. Select this option if the module is going to be plugged into female Round (Swiss) Sockets. This is very useful for prototyping! See picture on the right for some examples.
Typically the 6 pin female socket (low profile version) can be used for the main board.
We stock a range of swiss pin headers, available here.
Press-fit type pins are assembled. They can be pressed into 1.00mm holes on a 1.6mm thick (standard PCB thickness) target board. A press-tool might be required for production assembly. Once fitted to the target board, the board is very secure, and can not be removed by hand any more. The picture on the right shows an example of an iMod module mounted onto main board via press-fit connectors.
We stock a range of press-fit pin headers, available here.
The following order codes can be used to order this module:
Standard module with maximum +14dBm power. The frequency(868MHz or 915MHz) is configured via software.
High power module with maximum +20dBm power. The frequency(868MHz or 915MHz) is configured via software.
The following codes can be appended to the order codes shown above to add pin headers. See the “Pin Headers” section above for details:
For example, to order the “inAir9” board with a SMA connector, and standard 6mm pin headers assembled, use the following code: inAir9-h6