I buy’d this device recently too. My unit comes without GPS even though it was declared.
I have a lot of problems with downlink, becuase of time drifts I think. My log says enormous high numbers of drift, so I thought this is my problem.
I try to add an USB serial converter (ftdi) with an ublox 6M laying around, but this OpenWRT build doesnt have usb serial drivers and usb packages from repo doesn’t have packages for current running kernel.
So I decided to rebuild OpenWRT without Dragino auto provisioning and updating crap (connection to weird server adresses www.163.com and so on). After lots of trying and code studiyng how to interface SPI Ports, I get it to run. I am not a developer so it was not easy to me, but I suceed.
I cloned openwrt-18.06 stock clean repo not draginos one, added dragino feed and added only lora-packet-forwarder and luci-config for forwarder. I removed a lot of board autodetect fuctions because it hast detect mine LG308 as an LG02 often and configured only one SPI. I extend LuCi Config Page to add GPS Enable / Disable and GPS device path. Fake GPS and some other config parameters is now possible too. I fixed Logread tabs moreover.
I added some useful tools to OpenWRT too like screen, nano and htop. All often used usb serial converter drivers also added.
I wrote dragino and they uploaded schematics of the lg08 board to their github repo. I needed it to confirm SPI pinouts for SX1301 and onboard SX1276 (useable for tx, freeing resources on SX1301).
The hardware is very interesting, one SX1301, one SX1276 near SX1301 and one SX1276 onto main pcb. In total one SX1301 for RX and TX and two SX1276 for TX. Second SPI is connected to SX1276 which is default TX module and antenna connector connected to it. They modified lora_pkt_fwd.c to transmit via SX1276. If “send via SX1276” is not enabled in LuCi Config Page you need to reattach antenna cable to proper output to prevent damage transmitter. But I don’t know how to interface second SX1276 which is on a doughterboard which has the SX1301 too.
After adding my ublox via USB FTDI and config it properly, downlink is working without problems and have very low time drifts now (~300-950µs)
If someone interested in my OpenWRT build ask here. I dont know how to upload my modified code to github without all build files because it hast about 4,5GB. I can write a small text how I modified code.
It is not perfect at all, some LuCi Pages are not working now, but I am working on it.
Sorry for my bad english, I am not an english native speaker.