This repository contains the IBM LMIC (LoraMAC-in-C) library, slightly modified to run in the Arduino environment, allowing using the SX1272 LoRa tranceiver with an Arduino.

This repository is just a proof-of-concept to send data between two SX1272 modules. It is not intended as a complete library and was not tested in a full LoraWAN setup with a gateway (though feel free to fork it and turn it into one if you want).

If you want to actually use this code, note that it contains version 1.4 of the library, but there are newer versions available already. Also, the LMIC library needs to be modified to not invert IQ signals, in order to allow device-to-device communication as used in the raw.ino example, at the same time breaking device-to-gateway communication.

If you need device-to-device communication, make sure you reapply commit 7561aa74c (Do not invert I/Q signals to allow communication between nodes), which was reverted in master.

At this time, this code needs an hourly build of the Arduino IDE (or 1.6.6 once it is released), since that enables C99 code to be compiled.

Note that the SX1272 module runs at 3.3V and likely does not like 5V on its pins, so make sure to use a level shifter, or an Arduino running at 3.3V (this library was tested using a Pinoccio, which is an Arduino-like board running at 3.3V). The evaluation board has 100 ohm resistors in series with all data lines that might prevent damage, but I would not count on that.

The pins to use are shown (and can be changed) in the pinmap in example .ino files. It seems that connecting RST is not needed, and RXTX output on the Arduino side (which controls the RX/TX antenna switch) can be connected to the antenna switch (pin FEM_CTX on the evaluation board). Alternatively, you can connect the RXTX pin of the SX1272 directly to the antenna switch (by connecting RXTX and FEM_CTX together on the evaluation board, or moving R2 to R1). I'm not sure why you wouldn't always want this connection to be made, but apparently there is a reason to control the switch from the Arduino instead of from the SX1272.

The source files in this repository are made available under the Eclipse Public License v1.0, except for the examples which use a more liberal license. Refer to each individual source file for more details.