V20 OBD GPS Tracker, errors in log, no data

Hello,
I try to connect the tracker named above to traccar. As documented, I used the huabao protocoll, port 5015. TCP communication is established, however, decoding seems to fail. I get the "online" status in the WebGUI, gut the status parameters remain empty.
in the log-file I find:

root@cubietruck:/opt/traccar/logs# cat tracker-server.log | grep 5169492e
2021-03-10 07:18:04  INFO: [5169492e] connected
2021-03-10 07:18:04  INFO: [5169492e: huabao < 46.114.148.218] HEX: 7e00020000005704456646000a3e7e
2021-03-10 07:18:10  INFO: [5169492e: huabao < 46.114.148.218] HEX: 7e02000049005704456646000b00000000000c000202e9664f008e4e510030000d004721031006180681001e000000080000000202033b8f000000160071162a07630000592e00030d001d7e
2021-03-10 07:18:10  INFO: [5169492e: huabao > 46.114.148.218] HEX: 7e800100050057044566460001000b020000ba7e
2021-03-10 07:18:10  WARN: [5169492e] error - readerIndex: 85, writerIndex: 76 (expected: 0 <= readerIndex <= writerIndex <= capacity(76)) - IndexOutOfBoundsException (... < HuabaoProtocolDecoder:343 < *:179 < ExtendedObjectDecoder:52 < ... < WrapperContext:102 < ...)
2021-03-10 07:18:10  INFO: [5169492e] disconnected
root@cubietruck:/opt/traccar/logs# cat tracker-server.log | grep 0798c137
2021-03-10 07:18:21  INFO: [0798c137] connected
2021-03-10 07:18:21  INFO: [0798c137: huabao < 46.114.148.218] HEX: 7e00020000005704456646000c387e
2021-03-10 07:19:08  INFO: [0798c137: huabao < 46.114.148.218] HEX: 7e02000049005704456646000d00000000000c000202e9660b008e4eb50030000100a821031006190681001e00000000000000000000007a000000160000270f00000000000000000000e47e
2021-03-10 07:19:08  INFO: [0798c137: huabao > 46.114.148.218] HEX: 7e800100050057044566460001000d020000bc7e
2021-03-10 07:19:08  WARN: [0798c137] error - readerIndex: 102, writerIndex: 76 (expected: 0 <= readerIndex <= writerIndex <= capacity(76)) - IndexOutOfBoundsException (... < HuabaoProtocolDecoder:343 < *:179 < ExtendedObjectDecoder:52 < ... < WrapperContext:102 < ...)
2021-03-10 07:19:08  INFO: [0798c137] disconnected

Does anybody have any hint, what is going wrong, please?
Regards, Tomte

Are you using the latest version of Traccar?

No, I am running 4.11. I could update, but was not keen to lose the export capability. Not that I have ever used it.
N.B.: With the original website, www.obdgps123.com, the tracker was runnign fine.

Well, my best guess is that protocol has changed a bit, so it's not fully supported.

Ok, I just checked the sources, it seems, you are still working/maintaining the huabao protocoll (last change decoder 7.3.2021, i.e. 3 days ago). So an update to 4.12 might help?

It might.

I updated traccar to 4.12, and I am afraid, but it did not make a difference.
So if I can not fix it myself, I can only hope, that somebody might bother in the future, right?
I am surprised, that nobody else has noticed, so far.

You can either wait or you can sponsor the implementation.

Hello,

I really appreciate your support, and I can fully understand, that you can not do this for me for free.
But it is a relatively crappy and cheap GPS dongle. I think it is not worth it to spend any more money on it. I will wait.
If anybody wants to fix it and I can supply some data - feel free to contact me.