This is Edwin from Dragino. I am sorry that the LoRa IoT Kit cause these trouble in connecting to TTN. While you use end node to connect LoRaWAN via a Single Channel Gateway, there is indeed chanlleage because of hardware limitation.
The LoRa IoT Kit is provided as a low cost Kit to study LoRa technolog and LoRaWAN technology. We have improved the connection in the v2 version of the kit. Now it is able to use a modified LMIC version in Arduino to connect to LoRaWAN via OTAA and ABP. The latest insturction can be found here : http://www.dragino.com/downloads/index.php?dir=LoRa_IoT_Kit/v2-Kit/&file=Single%20Channel%20LoRa%20IoT%20Kit%20v2%20User%20Manual_v1.0.4.pdf
to see how to connect to LoRaWAN. And also the limitation for the connection.
The End Node in the instruction is Arduino with a modified LMIC library. If user use other end nodes, most properly can’t meet the requirement in the limitation: 1) Single Channel, 2) enlarge RXtimeout. For an demo on how other end nodes can connect, here is a video for reference:
So the Single Channel gateway LG01/LG02 are not recommend to use for LoRaWAN gateway.
Besides connect to LoRaWAN, LG01 and LG02 support LoRa connection with servers such MQTT, RestFul. The insturction can be found on the kit manual as well.