Lora App Server: GW GPS

Hey everyone!
Trying to figure out how to work with packet_forwarder sw (which runs on a vast number of GWs) and GPS antenna. The point is that I need to locate my GW on the map provided by Lora App Server web UI. Could someone give any ideas how the Server works with GPS data? I see that I can enter it manually while provisioning new GW.

Is it possible to “read” gps data directly and automatically from the GW?
Cause by default it shows me some random coordinates based on browser data.

Could you check the output of the ../stats topic of your gateway: https://docs.loraserver.io/lora-gateway-bridge/use/data/?

Does that output GPS coordinates?


No GPS data, which fact sends me to the config file of the pkg_forwarder. Here is the section related with GPS settings:

“gps”: true,

/* GPS configuration */
“gps_tty_path”: “/dev/ttyAMA0”,
“ref_latitude”: 0.0,
“ref_longitude”: 0.0,
“ref_altitude”: 0,

Catenating /dev/ttyAMA0 (GPS device):


As far as I can see cat is showing some kind of rubbish. Maybe this is where I should investigate? Cause I expected some readable information, like $GPRMC,113650.000,A,5648.6067,N,03639.3847,E,32.01,255.6,210403,E*69

Or there is a possibility that my reciever is faulty…=(

I recommend you to check the logs of the packet-forwarder process. I believe it will print some information about having or not having a GPS fix which could help you to debug this issue.

Some magic sh*t just happened and the GPS has started to work…For those of you who interested in model it’s GY-GPS6MV2 - works almost out of the box.

Anyway, Orne could you please indicate what is the proper date-time format for App Server? NMEA is ok? Just curious how to send dictionaries (massives) to the SW.

This is the format that LoRa Server expects (over MQTT) from your gateway: https://docs.loraserver.io/lora-gateway-bridge/use/data/

Can I expand this array? I plan to install humidity/temperature sensor within GW’s enclosure (for example) and want to send it’s data to the Lora Server. So the simpliest way I assume is to send temperature stats to specific topic using mqtt client, otherwise I need to recompile the whole pkt_fwd utility if I want to expand the array which GW sends to MQTT…So, assuming my data is in the topic the next step would be something like creating new app which one would read data from topic and represent it. Please note that I want to read temp stats from GW, Not from end node.
Sry for possible offtop,

Fri Mar 22 16:09:00 2024 user.info chirpstack-concentratord-sx1302[7856]: Enabling GPS device, tty_path: /dev/ttyAMA0
Fri Mar 22 16:09:00 2024 user.info chirpstack-concentratord-sx1302[7856]: Starting GPS validation loop
Fri Mar 22 16:09:01 2024 user.warn chirpstack-concentratord-sx1302[7856]: GPS time reference is not valid, age: 1711103941.747476548s
Fri Mar 22 16:09:02 2024 user.warn chirpstack-concentratord-sx1302[7856]: GPS time reference is not valid, age: 1711103942.748061103s

Can you guide on this ??

It means that the gateway was not yet able to sync the GPS time. Either the GNSS module has no fix or the GNSS is incompatible with the Semtech HAL (it needs to be an uBlox).