01-07-2010 01:58 AM - edited 01-07-2010 02:11 AM
It's nice to see that Lenovo has finally made the Fix interval time feature available as a selection in the GUI. This should remedy a lot of inaccuracy while driving using the GPS.
However, there seems to be a bug with this feature on a Thinkpad T500 2081-CTO (Ericsson F3507g) Windows 7 where NMEA commands will be sent every 1 "minute" on the destination port when the fix interval time is set to 1 "second" in the GPS Enabler GUI. (Note the different units) This makes the GPS port undiscoverable by most GPS software since the NMEA statements are sent at such a slow rate (1 min/statement).
When the fix interval time is set to "2" sec or above in the GPS Enabler GUI, everything works as expected (except for an additional second of lag for GPS NMEA statements).
I know this is not a hardware limitation since I was able to have the F3507g card manually send NMEA statements every 1 second by doing the following:
1. Close down Thinkvantage GPS
2. Stop the Mobile Broadband Core Service
3. Using HyperTerminal, open COM6, issue the following commands:
4. Using HyperTerminal, open COM4, issue the following command:
5. NMEA statements can be seen refreshed on COM4 every second (instead of 2 sec, or 1 min when using GPS enabler)
Clearly there is some kind of software bug somewhere, either located in the Mobile Broadband Core Service or witin the Thinkvantage GPS software itself.
It would be nice if anyone can confirm this or have this fixed.
P.S. Does anyone know if the GPS enabler enables DGPS by default? This card supports this function, but no such option can be selected in the GUI.
01-07-2010 11:56 AM
Just a little update on the situation.
DId a little research on it today, it does seem to confirm my observations:
This can be seen under Portmon on COM6 when GPS Fix Interval is set to 1.
Clearly there is some misinterpretation somewhere of this unit "1" and should be fixed.
It also seems that the GPS enabler does not specify the third argument for E2GPSCTL, I assume it's defaulted to off when the argument is not specified - any plans to add it into the GUI as well?
01-07-2010 11:59 AM
Yea, there is a bug either in the driver or in the GPS enabler itself where it is interpreting 1 sec as 1 min for GPS fix interval time. This makes the GPS location refresh at such a slow rate (1 min per update) that you will never really have a fix.
01-09-2010 07:28 AM
Nice bit of work. I've been trying to get GPS working on my new W500 (win7-64) for a month with no joy. Seemed as if the GPS function might be working but never got a fix. I didn't get down to the low level analysis. So it feels to me that I could be also suffering from the 60 second bug. Driver = 2.41. I have not yet downoaded 2.50 because TVSU 4.0 is not yet showing it in the download list (along with some pre-reqs) and I don't want to install manually. Hopefully Lenovo will get a move on adding them to the download list. Hint Lenovo !! However it seems that you find 2.50 to be broken also, so I'll report back as and when anything improves ....
02-11-2010 06:57 AM
Any luck on getting this fixed. I have 7-64bit on my T500 as well and I can't seem to get my GPS to work. It's been a while now since this post was stared. Are we to expect any updates soon?
02-11-2010 08:05 AM
Yes! I got it working (W500 + Win7/64) the other day. I manually downloaded and installed V2.50 of the GPS driver from http://www-307.ibm.com/pc/support/site.wss/MIGR-73724.html#summary. I do not know if it currently shows up in Lenovo System Update. (For more than a month over Christmas and January I and many others noted that no updates were being made available, but I see some are now appearing in System Update. Since I have already installed GPS 2.50, System Update obviously is not offering it to me, so I cannot tell whether that is because I have already got it, or because System Update has not got it !). In any case, I suggest install it, and any pre-requisites. The only other suggestion is (obviously) the Thinkpad has to have a clear view of the sky (inside a house is unlikely to work), and it will take 5 minutes or more to make the first satellite acquisition.
02-15-2010 01:45 PM
2.50 has been working on my win7 t400 for some time but i notice that when i start up the gps it always picks up the sats much faster if i immediately stop and start again. any ideas why?
02-16-2010 01:53 AM
I own a SL-500 with 3G Ericsson module an win7 pro 32bit (3G card properly installed and TVGPS ) .
I have the problem that GPS doesn't work properly- perhaps you can help me.
I have GPS port on Com4 , Device Management on com6 and the modem port on com 5.
WIn7 recognises also a Localization device on COM4.
Starting TVGPS doenst enable GPS on my Notebook.
I can enable it manually by sending the AT commandy on COM5 - But then I have the NMEA Stream on COm 5 and
as soon as I close the terminal/ GPS prog from which I send the AT commands - the stream ceases( goes off)
COM4 does accept a connection but I cannot send any AT's.
Anyone with an Idea ? I really need the GPS :-(
03-28-2010 03:50 PM
I also have the same problem. While I am not sure what exactly is causing the issue, it could be that the Ericsson is hiding the satellites until it acquires a fix. Once I acquire a fix, usually many satellites come forward. But you are right though, I find that it takes longer to fix (or very long to fix) if you just go straight from a cold start. It does seem that stopping and restarting it causes it to fix faster (perhaps because it is in a "warm" state). Just my two cents though.
You will have to send your AT commands on COM6. Once you send your AT commands on COM6, the NMEA stream should be sent to your COM4 port and you can close the terminal. What AT commands are you exactly sending by the way? Also, the Lenovo GPS application requires that the Mobile Broadband Core Service be started under System Services. It will give an error if that's not properly started. Good luck.