This is LoRaWAN stack for the GMX-LR1 node. It is based on ST I-CUBE LRWAN , which in turn is based on Semtech code.
We find that ST implementation easier to use to add your own application on top of it, which could be not necessarly a simple sensor that transmits data every n-seconds, like the basic example in Semtech's code.
We have further extended the code to make it even easier to add you application.

We are publishing the stack as an Atollic Studio project, download the free-version here and start developing immediately ( we find Atollic Studio the best compromise between free and 'commercial' ARM IDE )

The GMX-LR1 is the node we are using in Gimasi for all our LoRa IoT applications, its one of the possible RF-addons for out multiprotocol TUINO maker's IoT platform.

Here is a picture of the node (beta version), in this picture there is also it's companion board that make it's very easy to fast prototype your sensor.