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Carl@SiRF
USA
158 Posts |
 Posted - 28 mars 2007 : 19:01:24
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SiRF protocol is simply a communications protocol. Yes, customers of ours can disable it, but few do. I am not sure what you mean when you say you can still send cold resets. Either you have communciation with the receiver or you don't. And there is no reason the receiver should work in NMEA mode and not in SiRF binary protocol. If you can talk to it in binary protocol, send it a factory reset command with SiRFDemo and you should restore all default settings.
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Carl - SiRF Customer Support |
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einstein-a-go-go
6 Posts |
Posted - 28 mars 2007 : 19:59:52
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I'll try and explain a little bit clearer.
After sending a Switch to Sirf Protocol via SurfDemo or otherwise, all communication stops on all baud rates, but also the GPS Receiver Green LED (flash - fix, steady - no fix) goes out.
Solution to fix this, is to short out pins, remove battery for 24 hours.
Sending a cold reset, does restart comms, and doesn't resume NMEA mode. |
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einstein-a-go-go
6 Posts |
Posted - 28 mars 2007 : 20:01:34
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| I would have throught that Switching to Sirf Protocol, would still cause it to retain GPS fix, and continue sending Sirf data, although you may have the wrong baud rate selected. |
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Carl@SiRF
USA
158 Posts |
Posted - 29 mars 2007 : 00:17:50
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| You are right -- simply switching protocol does not cause loss of fix. However, they may have removed SiRF protocol and not removed the command to switch (I've seen that done more than once). Solution: don't switch protocol! I know that leaves you without abilities to change parameters, but that is manufacturer's choice. |
Carl - SiRF Customer Support |
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einstein-a-go-go
6 Posts |
Posted - 29 mars 2007 : 00:32:11
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Carl - Thanks for your prompt reply.
So how can you tell if the Sirf III Chipset GPS you are purchasing has a "full implementation" of the Sirf III Protocol to configure? i.e. turn off/on static navigation for use with walking and running, these GPS's would be of no use or not accurate (not fit for this purpose). But okay for vechile tracking Tom Tom etc
It's a little misleading to the end user, purchaser, for the Seller to advertise Sirf Chipset logos all over the product, only to find, it's not 100% Sirf!
In the UK, this is mis-representation of the product I believe.
Andrew |
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Carl@SiRF
USA
158 Posts |
Posted - 29 mars 2007 : 00:36:12
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| The tracking and navigation algorithms are still 100% SiRF, as is the hardware. The only flaw is that your manufacturer chose some of the settings for you and didn't trust customers enough to allow them to change things. I don't know UK law, but here in the "colonies" I don't think you would get too far in court ... |
Carl - SiRF Customer Support |
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einstein-a-go-go
6 Posts |
Posted - 29 mars 2007 : 00:41:32
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Thanks for your reply.
I think the answer here, is don't purchase hokey cokey 9000 units from Taiwan, and purchase a well known brand, but I've also seen well known brands that also don't support Binary Sirf Data. So it looks like "some companies" are trading on Sirf's Good name to sell product!
and the result is the end user willpay the price.
Thanks for your time Carl.
off to purchase a real Sirf Binary GPS...
I assume the real mcoy Tom Tom GPS is! |
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admin_0
1 Posts |
Posted - 30 mars 2007 : 05:58:01
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I am currently setting up a USGlobalSat ET-102 for GPS research (logging the CNo/50bps data over time specifically) using SiRFDemo 3.83 to test it during the setup phase. However, it seems to have some serial communications problems. Using the manual baud rate changing trick in this thread removed various CE_Errors and it successfully navigates in NMEA and SiRF Binary mode upon powering up, reporting satellites and signal strength and calculating a fix.
However, after 30 seconds-1 min SiRFDemo reports "Rejected:MID_Nak" errors in the Response window and stops navigating (signal, map and radar go blank). Resetting the receiver either by cycling power or pulling the reset pin low causes it to begin navigating again for the same short length of time. In addition, logging incoming navigation messages does not work and polling is very slow.
Is there any reference for the cause of the MID_Nak error (I tried these forums and Google with no results) and do you think this is a SiRFDemo issue or a problem with the receiver HW/Firmware?
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Carl@SiRF
USA
158 Posts |
Posted - 30 mars 2007 : 19:18:49
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Periodically, SiRFDemo will query the receiver for various settings (typically during log file collection). MID_Nak means that the receiver was unable to comply with the request. Typical reasons why it would NAK are 1) incoming message failed parity, 2) some field of the incoming message had invalid data, 3) the receiver was not in a position to comply (e.g., receiver was asked for data that does not exist in that type of software).
I can only speculate on what you are seeing here, as I haven't seen it before. This has the feel of a receiver that is overloaded with some internal user task, running right near the limit for capabilities, and that whatever the incoming message is, it puts things over the limit and the system crashes. A second possibility (although symptoms don't quite match expected) is that this receiver has a demonstration copy of premium software that has reached its preset life.
Suggestion: Open SiRFDemo, open a log file, then connect to the receiver, then apply power to the receiver. You should be able to log everything in this setup. When the crash occurs, you should have a record of what message was sent to the receiver. It will be logged in hex, but you can decode it using the binary protocol manual. |
Carl - SiRF Customer Support |
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ricfranz
Italy
2 Posts |
Posted - 31 mars 2007 : 17:36:46
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When I try to connect my Gps BT receiver, after activating BT on Com 7, I receive this error message:
Cannot create UART handle.
Com port is not avalaible or is nt in use.
What can I check to resolve? |
Edited by - ricfranz on 01 avr. 2007 10:35:55 |
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ndharris
7 Posts |
Posted - 31 mars 2007 : 20:58:15
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quote:
Originally posted by Carl@SiRF
Guillaume is correct. The issue has been addressed, at least in part. There will likely be more changes in that area as we keep refining how we do things. But the overall fix for receivers that have 3.1.1 software is simply to cycle power.
Carl, is there any update regarding this? We are experiencing the same "deep search" problem (device takes up to 30 minutes to recover from a lost fix when left on indoors). We embed your SiRF III into our device, and cycling the power on our device will not cycle the power on the SiRF chip because it is still connected to the batteries. Have you guys released a software fix to the problem, and if so, what version?
Thanks, Neil. |
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frder
Italy
45 Posts |
Posted - 01 avr. 2007 : 13:59:21
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quote:
Originally posted by ricfranz
When I try to connect my Gps BT receiver, after activating BT on Com 7, I receive this error message:
Cannot create UART handle.
Com port is not avalaible or is nt in use.
What can I check to resolve?
Pannello di Controllo->Dispositivi Bluetooth->Periferiche
Select your GPS BT device listed in "Tutte le altre periferiche"
Proprietà->Servizi
check if "Porta Seriale (SPP) Serial Port" is activated and which is the associated COM Port
Check if there are other applications using that Com Port
Try to connect with Sirfdemo at all the possible Baud rate.
Ciao
francesco |
Edited by - frder on 01 avr. 2007 14:02:46 |
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ShawJohn
United Kingdom
5 Posts |
Posted - 06 avr. 2007 : 17:49:17
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I have a Holux GR-213 GPS mouse which after some tinkering in SirfDemo (3.75 & 3.81) will no longer receive commands and will only output Sirf Mode at 57600.
It makes no difference if I factory reset it.
All this does is clear the sat. data, it continues to output Sirf Mode regardless.
My problem is that most of my GPS software is NMEA only... The only reason I ever put it into sirf mode was to turn on Track Smoothing, now its stuck there!
I've had a try at opening the case in order to try out removing the backup battery, but it looks impossible to gain entry without trashing the case :(
Could I send a binary message to reset it back to NMEA? If so what is the command?
I have tried contacting Holux both in TW and UK with no luck and no responses :(
Can anyone help? |
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Carl@SiRF
USA
158 Posts |
Posted - 06 avr. 2007 : 18:16:29
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Using SiRFDemo, go to the Action menu and select Switch to NMEA Protocol. You will get a menu to set message rates and baud rate. If that doesn't work for some reason, on the Action menu open the Initialize Data Source menu, and on that menu, select Factory Start in the lower-left corner, then SEND. Watch in the Response View window for the ACK of your command. If instead you see NAK, something has gone wrong with the command, or the receiver is unable to comply.
Final option: find a way to remove the battery long enough to kill BBRAM. |
Carl - SiRF Customer Support |
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ShawJohn
United Kingdom
5 Posts |
Posted - 06 avr. 2007 : 18:37:51
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I tried both of those methods, each time sirfdemo changes to the new settings and I get the following error messages:
IN DEBUG WINDOWS: Comm: CE_Frame
AND IN RECEIVER OUTPUTR: 255 0xFF
These repeat over and over until I change the main serial port info back to 57600, then it all starts reading Sirf data again :(
I had a quick read of the sirf manual and apparently it should output some message that it was unable to carry out the command and it isn't doing.
I know I can rip the fecker open and remove the battery but all attempts to do this without trashing the case have failed! |
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SiRFdemo tutorial (static navigation)
