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BeamRider
Italy
6 Posts |
 Posted - 28 oct. 2004 : 14:34:12
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UPDATED 2009 : Detailed information posted by Camomille here on page 2.
Does anyone has specification for the GNS protocol 1.0 or 2.0?
I've done some reverse engineering from a tiny serial log I've found on the net, but I still miss commands from PDS/PC to the GPS unit to initialise and tune station.
I'll be very glad if someone has or can produce a long log file with TMC messages to test my TMC decoder: in my country I've TMC service but with a subtype of TMC messages only and I know that in Germany and UK service is complete.
Many thanks
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gpspassion
84985 Posts |
Posted - 28 oct. 2004 : 15:50:59
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| Interesting idea! Where are you located? As for producing a log I'd be glad to help, but I don't know how a full log can be created, other than a standard NMEA log? |
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BeamRider
Italy
6 Posts |
Posted - 28 oct. 2004 : 16:46:28
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Hi,
I'm from Genova(Italy).
A NMEA log is exactly what I'm looking for but be sure to tune to a TMC station please(obivious but imperative). In the log file you'll see some strange packets mixed with NMEA strings. These are RDS groups, TMC messages are coded inside a specific RDS group.
As I said, I'm able to decode them but not sure if my code supports the multigroup TMC message type. I implemented the decoder using the ISO specifications so I'm quite sure it'll work.
My project goal is to give textual TMC messages in a window where an GPS/RDS unit is used as emulating the unit using my own hardware and a conventionsal GPS. Actually the first phase is complete (awaiting to test with your log  ), the second is in development. The platform I'm using is Windows but the code is portable to PPC without too much work. |
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gpspassion
84985 Posts |
Posted - 28 oct. 2004 : 17:00:16
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| Not sure I'm following the emulation part? If you have something to test on a PC, I'll be glad to help. On the log, problem is that with the 9810/30 you need to switch them in GPS" mode for them to work with a normal GPS program that can log. The Modular is different, I'll check a log. You're going to need the TMC tables too, can they be bought? |
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BeamRider
Italy
6 Posts |
Posted - 28 oct. 2004 : 17:19:31
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Let's go deeper on it 
Let's suppose that you have a normal GPS and you want to use it with your TMC enabled navigator software (Navigon, Alturion, D3 PRO, ecc..). Then my project get GPS data from the receiver and RDS data from a small unit I've built around an USB FM radio. The code creates a virtual com port that emulates the behaviour of the GNS 98xx unit feeding the navigator with GPS and TMC data. That's all for emulation.
For the log you can try a software GPS splitter like GPSGate (I think it can write a log while sending data to the software) resolving your initialisation issue. The resulting file is binary (RDS group are binary).
The TMC databases are free of charge and usually given by national traffic bureaus. The good thing is that my code is binary compatible with Tricksy databases. I can send you an executable version of my code in a few days (just give me the time to clean some parts). It's ugly and unoptimized but runs on any Windows PC.
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Edited by - BeamRider on 28 oct. 2004 17:36:18 |
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gpspassion
84985 Posts |
Posted - 28 oct. 2004 : 17:36:32
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I get it, very interesting indeed! I'm on a trip right now and only have the Modular GPS with me, I'll log to see if there are any odd messages. If that doesn't work I can log data from the 9830 nextnweek. GPSGate does ask you to connect in NMEA doesn't it, unless there's an option I've missed?
Also how do you get the data from your hardware into the PC/PocketPC ?
Feel free to pass on your .exe when you're ready ;-) |
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BeamRider
Italy
6 Posts |
Posted - 28 oct. 2004 : 17:44:29
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Thanks a lot, if the modular is GNS compatible then you'll see something like:
$GPGSS.........?xxxxxxxx?......
where xxxxxxxx is the 8 byte RDS group. The position inside the NMEA string isn't fixed, that's why you have to configure the 98xx in NMEA mode to make it work with non TMC software.
My hardware needs only a free serial port connected to an RDS demodulator. RDS data stream is synchronous so I don't use RX line of the com port but a sort of interrupt driven logic. Synchronisation and error control/correction is described in ISO documentation.
I'm glad you're interested in my project, you'll surely receive it ASAP.
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Edited by - BeamRider on 28 oct. 2004 17:46:45 |
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gpspassion
84985 Posts |
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BeamRider
Italy
6 Posts |
Posted - 31 oct. 2004 : 09:46:30
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I've used GPGSS string as an example only: the RDS data is mixed with NMEA in every string (sorry, I don't know very well the NMEA strings meanings).
Is possible that modular sends RDS data only in Sirf mode? That behavior can explain why modular can be logged with conventional GPS software while GNS not.
I've got informations only for GNS units so please can you try with 98xx if/when you're able to?
Many thanks |
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CarPC
United Kingdom
2 Posts |
Posted - 20 juin 2005 : 12:58:13
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| I have just bought a GNS 9830 GPS/TMC receiver. This came with no s/w to tune the radio so I cannot see any TMC messages. Does anyone have any s/w or information on the GNS 2.0 protocol which would help me do this? I can write my own code if necessary, but first I have to know what messages the 9830 expects. |
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gpspassion
84985 Posts |
Posted - 21 juin 2005 : 09:55:32
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I don't think GNS have released details on how it works. I haven't seen any tools so far that could decode it, only navigation software that uses it, like Navigon, Alturion or Destinator.
_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer? |
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mullions
France
24 Posts |
Posted - 16 août 2005 : 11:57:52
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Hello,
to get the GNS protocol, you need to buy their SDK...or speak German.
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admin_0
1 Posts |
Posted - 27 mars 2006 : 19:19:06
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quote:
Originally posted by CarPC
Does anyone have any s/w or information on the GNS 2.0 protocol which would help me do this?
Did you succeed in finding the GNS protocol online ?? |
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PitaGyros
Germany
5 Posts |
Posted - 14 juin 2006 : 12:36:46
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quote:
Originally posted by BeamRider
Thanks a lot, if the modular is GNS compatible then you'll see something like:
$GPGSS.........?xxxxxxxx?......
where xxxxxxxx is the 8 byte RDS group. The position inside the NMEA string isn't fixed, that's why you have to configure the 98xx in NMEA mode to make it work with non TMC software.
Hi!
I wanted to ask if someone could post a NMEA dump in the forum. I am especially interested in the GPGSS messages.
Thank you very much!
PitaGyros |
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davboubou
1 Posts |
Posted - 26 juil. 2007 : 18:06:30
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Does someone finally got some information on the GNS protocol and how to initialize a GNS TrafficBox?
Disassembling their GpsRdsRun_PC.exe, I found out that it writes 5 bytes(0xff,0x46,0x00,0x78,0x46) on the COM port, but it didn't work for me.
Thanks for any information. |
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VolkerSchulz
4 Posts |
Posted - 04 oct. 2007 : 23:39:11
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Hey guys!
Any progress in working with the GNS 2.0 protocol? I've bought a GNS 5843 (Bluetooth) just today and am still trying to figure out the TMC thing.
It works fine with my navigation software (Destinator PN) on my smartphone. I figured out that the GPS receiver sends standard NMEA only until TMC is activated (by some sort of command), which happens after my navigation software is started.
BeamRider: Which ISO specifications did you use to decode?
Find a first data log here:http://www.capuzza.com/nmea/. First with no TMC messages, then with TMC activated.
If somebody has useful information about GNS 2.0 or decoding the 8 byte messages, please let me know. Will be glad to upload more data logs if neccessary.
Cheers,
Volker |
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[GUIDE] Decoding the TMC Protocol (GNS°
