Arduino LoRa

An Arduino library for sending and receiving data using LoRa radios.

Compatible Hardware

• Semtech SX1276/77/78/79 based boards including:
  • Dragino Lora Shield
  • HopeRF RFM95W, RFM96W, and RFM98W
  • Modtronix inAir4, inAir9, and inAir9B
• Arduino MKR WAN 1300
  • NOTE: Requires firmware v1.1.6 or later on the on-board Murata module. Please use the MKRWANFWUpdate_standalone example from latest MKRWAN library release to update the firmware.
  • WARNING: LoRa.onReceive(...) and LoRa.recieve() is not compatible with this board!

Semtech SX1276/77/78/79 wiring

Semtech SX1276/77/78/79	Arduino
VCC	3.3V
GND	GND
SCK	SCK
MISO	MISO
MOSI	MOSI
NSS	10
NRESET	9
DIO0	2

NSS, NRESET, and DIO0 pins can be changed by using LoRa.setPins(ss, reset, dio0). DIO0 pin is optional, it is only needed for receive callback mode. If DIO0 pin is used, it must be interrupt capable via attachInterrupt(...).

NOTES:

• Some boards (like the Arduino Nano), cannot supply enough current for the SX127x in TX mode. This will cause lockups when sending, be sure to use an external 3.3V supply that can provide at least 120mA's when using these boards.
• If your Arduino board operates at 5V, like the Arduino Uno, Leonardo or Mega, you will need to use a level converter for the wiring to the Semtech SX127x module. Most Semtech SX127x breakout boards do not have logic level converters built-in.

Installation

Using the Arduino IDE Library Manager

1. Choose Sketch -> Include Library -> Manage Libraries...
2. Type LoRa into the search box.
3. Click the row to select the library.
4. Click the Install button to install the library.

Using Git

cd ~/Documents/Arduino/libraries/
git clone https://github.com/sandeepmistry/arduino-LoRa LoRa

API

See API.md.

Examples

See examples folder.

FAQ

1) Initilizating the LoRa radio is failing

Please check the wiring you are using matches what's listed in Semtech SX1276/77/78/79 wiring. You can also use LoRa.setPins(ss, reset, dio0) to change the default pins used. Some logic level converters cannot operate at 8 MHz, you can call LoRa.setSPIFrequency(frequency) to lower the SPI frequency used by the library. Both API's must be called before LoRa.begin(...).

2) Can other radios see the packets I'm sending?

Yes, any LoRa radio that are configured with the same radio parameters and in range can see the packets you send.

3) Is the data I'm sending encrypted?

No, all data is sent unencrypted. If want your packet data to be encrypted, you must encrypt it before passing it into this library, followed by decrypting on the receiving end.

4) How does this library differ from LoRaWAN libraries?

This library exposes the LoRa radio directly, and allows you to send data to any radios in range with same radio parameters. All data is broadcasted and there is no addressing. LoRaWAN builds on top of LoRA, but adds addressing, encryption, and additional layers. It also requires a LoRaWAN gateway and LoRaWAN network and application server.

5) Does this library honor duty cycles?

No, you have to manage it by your self.

6) Which frequencies can I use?

You can use this table to lookup the available frequencies by your country. The selectable frequency also depends on your hardware. You can lookup the data sheet or ask your supplier.

Please also notice the frequency dependent duty cycles for legal reasons!

License

This libary is licensed under the MIT Licence.