GF-22, TRV protocol, no gps location

Hi,

I'm just starting with GPS tracking devices and traccar.

the device

I bought a cheap GF-22 (whatever that is...). By default it connects to 360gps.net. I checked that the location is tracked and reported there, so the device is working.

what I alread achieved

I setup a traccar instance. I configured the device to connect to my traccar instance. By using the logs and the the hex2text conversion, I found out that this device is using the TRV protocol. I updated the port accordingly on my device.

the problem

After a while the device came online in traccar, but it seems, that it doesn't send any coordinates.
This is from the logs:

2022-02-17 03:36:51  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:36:51  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:39:51  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:39:51  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:42:51  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:42:51  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:45:52  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:45:52  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:48:52  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:48:52  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:51:52  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:51:52  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:54:53  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 03:54:53  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 03:57:53  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303936303030323030363030303032303430303030393939393223
2022-02-17 03:57:53  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 04:00:53  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303936303030323030363030303032303430303030393939393223
2022-02-17 04:00:53  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 04:03:53  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303937303030323030363030303032303430303030393939393223
2022-02-17 04:03:53  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 04:06:54  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303936303030323030363030303032303430303030393939393223
2022-02-17 04:06:54  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 04:09:54  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303936303030323030363030303032303430303030393939393223
2022-02-17 04:09:54  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
2022-02-17 04:12:54  INFO: [e94f4b16: trv < 80.187.70.109] HEX: 545256595031362c313030303035303936303030323030363030303032303430303030393939393223
2022-02-17 04:12:54  INFO: [e94f4b16: trv > 80.187.70.109] HEX: 5452565a50313623
...

So it's the same pattern all the time. I guess the device is expecting some different reply.

Any ideas? Thank you!

Do you have protocol documentation?

Hi,

I got a bit further: I found another questions in this forum with similar issues. In a screenshot in the product manual I found "S1903" which helped me to find out more. Actually the location is reported, together with the surrounding Wifi networks!

I tweaked some numbers and names, but this is from my log:

TRVYP14220217A5234.7885N00734.1840E000.0130919177.561000050660000200004,262,01,14635,52789,FritzBox7|DC-39-6F-7E-94-72|-89&FritzBox7|blabla|-90&NETWORK|anothernetwork|-81&wow|readynet|-80#

I found the protocol description in this thread: mini-gf-21-protocolo-s1903

This is the direct link to the pdf:
https://mega.nz/file/bMZW2TCA#4mZBtUeme9Ktipy0EGPdKkMShvSXSqCd8f5j5eB6-js

I hope this helps (crossing fingers...)

Thanks in advance!

Have you checked your logs against the documentation?

yes, at least for the messages from the logs, it seems to match!

I'm already trying to understand and decode it and see whether the coordinates are usable. The documentation is a bit confusing. That english is even worse than mine...

ok, this decodes the location update from the logs. It completely matches the protocal documentation:

https://dotnetfiddle.net/cVnQFI

I hope this helps.

My guess is that format has changed or extended and it's not fully supported.

yes, maybe the format has changed. Do you think you could add it to the project? My code snippet shows how these messages can be decoded. It looks like I'm not the only one with such a device.

We can, but we have a lot on our plate, so unless you are interested in sponsoring the work, it's unlikely to be prioritized. But either way you can add it to GitHub as a request.

I guess you mean a feature request. But would you also accept a pull request?
Sorry, sponsoring is not an option. I guess another tracker would be cheaper for me. But if I contribute to this project, others would also benefit.

Sure, pull requests are always welcome, assuming it's good quality and it line with other code in terms of naming, formatting etc.

Sure, I would try to stay in that "style". I take a look...

Wow, a really small fix. Pull request is pending.
15 years without java :)

Hi,
What is the FIX ? Is there a status update ?