Hex Decoder Gibberish. Why?

sebi53614 years ago

I have a Chinese Clone GPS Tracker.
I tested a bunch of ports and made it work flawlessly on Traccar with port 5013.
Based on the supported devices page, port 5013 corresponding protocol seems to be h02.

I am trying to verify that my protocol is indeed h02 based on the content of my tracker-server.log file:

2020-03-24 14:52:56  INFO: [5541b115: h02 < 5.35.166.138] HEX: 2491711824631352522403204337228604003505090c000000ffffdfff0000197d0000000000d0140110c8fae7
2020-03-24 14:52:56  INFO: [5541b115] id: 9171182463, time: 2020-03-24 14:52:52, lat: 43.62048, lon: 3.84182, course: 0.0

The Hex decoder of the HEX part gives:

[binary data]

...which looks like gibberish to me and has nothing to do with:

'h02' : '*HQ,123456789012345,V1,121300,A,6000.0000,N,13000.0000,E,0.00,0.00,010112,ffffffff,000000,000000,000000,000000#'

...found in the test-integration.py file.
What am I doing wrong? Thanks!

Anton Tananaev4 years ago

You should carefully read the supported devices page, especially what's written at the top.

sebi53614 years ago

I am sorry but I don't get what I should understand from that page.
That port 5013 is not related to protocol h02 only?
Can you be more precise?

Anton Tananaev4 years ago

If you own a Chinese device, please make sure to check the page about clones.

sebi53614 years ago

Yes I have read the page about clones.
That's why I tested many ports and ended up making it work with port 5013.
But I also tried to identify the protocole and this is where I am having trouble analysing the HEX string.
What should I understand from the page about clones that I didn't understand?

Anton Tananaev4 years ago

Well, H02 supports both text and binary formats. HEX decoder obviously won't work on the binary.

sebi53614 years ago

OK.
So if I understand right my HEX string contains latitude, longitude, etc. encoded with the h02 protocol, but in a binary format that cannot be decrypted by the HEX decoder. Is that right?
Is there an alternative tool to decrypt it?

Anton Tananaev4 years ago

HEX decoder only works if it's a text protocol. It doesn't work for binary ones. Some vendors provide tools to decode their binary protocols, but there's no generic tool for obvious reasons.

sebi53614 years ago

Got it.
But Traccar knows obviously how to decrypt it.
Do you know in which part of the code this is done?

Anton Tananaev4 years ago

It's done in protocol decoder.

sebi53614 years ago

Thanks

Foxchip4 years ago

I have also a H02 device : CCTR-830G
How to know with information are sent by the tracker? I would like to know if I can read fuel information!

sebi53614 years ago

Looking at the State Panel in Traccar, additional information than latitude and longitude is given (E.g., a warning if my tracker is disconnected from its main power source). You should have a look there to see if information about fuel is mentioned.

According to the sample in the test-integration.py file regarding the h02 protocole, there are many additional information than the latitude and longitude. The code of the protocol decoder should give you some clues too.

But I am not an expert...