Unit is based on the RN2903 which comes a nice text based UART interface out of the box.
LoRaWAN has a couple of different modes or class specifications a device can operate on. The 2903 comes with LoRaWAN class A support which has a short receive window after each transmit. This is great for low-power sensors and battery operated devices. Not great if you want to control something remotely or have it listening constantly without first transmitting. Class C is the specification which allows for this type of operation which is more suited for PCs, Raspberry Pis, and most anything with a dedicated power supply.
The full firmware is not open-source, but they do offer libraries that make interfacing with the LoRa radio easier and it's possible to support class C, but you have to re-implement or invent your own AT-like interface if you want to use it over UART, because that part is not open.
I'm looking to write some custom Firmware to support class C and I'm working on a Google Chrome plugin that will allow you to load new firmware easily over the boot-loader uart interface without trying to fuss with the Microchip tools.