GPS staying on after a random set time

[jjnz1]

i Have nokia n82 and full version gsm tracker 3.14
i have a problem. When i start my phone and the gsm tracker starts, it wakes up the gps, sends the data over 3g to home server, then sleeps gps module. (as it should because it's set to powersave after fix)
but after a random set time (normally between 30minutes to 2 hours) the gps unit wakes up and sends info but does not go back to sleep. -which causes my battery to go dead fast!

I decided to uninstall gsm tacker and reinstall it from a fresh copy off the web site, but still does the same random thing.

any help would be appreciated

Here are the settings i have
GPS, startup -on
gps, max fix -2
gps, powersave -on
gps, retry -10
gps, api -on
net, store ap-on
net, startup conn -on
net, disable bill -on
net,optional host, login.trackme.net.nz
net, server -30175
net, conn reset-0
net, transport-tcpip
net, username --
net, password --
net, gpsgate prot -on
http, nothing changed
trig1, time trig -on
trig1, time period -30
trig1, secound period -0
trig1, distance -off
trig1, cell trigger -off
trig2 no change
cell no change
file no change still off
sms no change except gps actv by sms -on
misc calc speed in km/h -on
misc, system and autostart -on

thanks joel

[jje]

Thanks Joel for the detailed report.

I think the main reason in your case is the "Trig1, Time period, min" value.
Try changing "Trig1, Time period, min" to 1
You can also set "GPS, Retry after, min" to 30.

"Trig1, Time period, min" should be less than or equal to "GPS, Retry after, min".
Otherwise "Powersave after fix" does not work as expected. The feature gets activated only when GSM Tracker sends some data. Data sending is controlled by the triggers.

A short time trigger allows the "Powersave after fix" feature getting activated as soon as possible after the GPS has been waked up.
Especially since you have "SMS, GPS activation by SMS" turned on, I would try a small "Trig1, Time period" value.

If the above does not help, try turning the setting "SMS, GPS activation by SMS" off. Does the "random thing" still appear?

--

Below I have listed a few general pitfalls in the current implementation.
I found these now when examining the powersave logic in GSM Tracker 3.14.
You may skip these if you think they do not concern your case.

Pitfall 1)
-----------
GSM Tracker 3.14 does not set the GPS into "sleep mode" until the following conditions are met:

1) Some trigger or user command causes GSM Tracker to send GPS data.

2) The status field in the NMEA $GPRMC sentence is 'A' indicating that the GPS receiver thinks the fix is valid.

3.a) The HDOP value received in the last NMEA $GPGGA sentence is less than or equal to the setting value "Trig2, Max HDOP"
3.b) or the setting value "Trig2", "Max HDOP" is zero.

On the other hand, the timer behind the setting value "GPS, Max fix wait, min" is cancelled straight, when the application receives a $GPRMC sentence with status 'A' from the GPS, irrespective of the HDOP value.

Now I see that there is a gap in the powersave logic, if somebody has put a very small "Trig2, Max HDOP" value and the prevailing satellites geometry is bad but still good enough for getting status 'A'.
Then the GPS chip may stay active for a long time until the satellite geometry gets better.

Resolution: in the current version it is safest to put the setting "Trig2, Max HDOP" to zero, if powersaving is important.

Pitfall 2)
-----------

Powersave works only, when the charger is disconnected.
If there is a problem with the sensor, which detects the charger status, then the GSM Tracker powersave logic does not work properly.
If you turn on the setting "Misc, Diagnostics mode", then you can see a message in the Log tab each time the charger is connected and disconnected.

-----------

If none of the cases above explain your case, I am willing to do more troubleshooting.
In this case answers to the following questions would be very helpful:

(Please keep the setting "Misc, Diagnostics mode" turned on.)

1) What messages do you see in the log tab, when the gps unit does not go back to sleep.
2) What do the little counters show in the bottom line of the state tab? Is the middle number increasing constantly and is the rightmost figure nonzero?
3) Does the GPS have a good fix? (UTC Time increasing, Latitude and longitude good, no questionmark in the leftmost icon.)

Thanks again for your report. Hope this information is useful to you or some other users.

-Jyrki

[jjnz1]

Thanks, it worked! I just change the value of the Trig1 time period to 10 minutes and set the gps retry to 25min. I left the sms activation thing on too. I have been testing it for a few days now (without charging battery which is only down to half) and it is working well. Didn't know that the value of the trig1 time should be less than the gps retry time.. but now i do.

Thanks for your help -most appreciated!

[jje]

This is a copied message from a GSM Tracker v3.15 user:
---
I'm having probelms with this GPS powersave. I've read all these posts and manuals, I know about the relation between GPS retry and trigtime, I know it doesn't go powersave if the phone (N96 in my case) charching etc.

I've been testing now with these:

GPS on startup ON
Max fix wait 2
Powesave ON
Retry after 3
Trig1 Time ON
Trig1 Time 3 MIN (Same as GPS retry)

Trig1/2 everything else off/0

When I try in inside where the GPS doesn't get a fix, it works just like I understand it should. Every 3 minutes it tries to get a fix for 2 minutes, and shuts down the GPS after that.

But when I go outside, the GPS doesn't go off after it gets a fix. Then it goes like this:

-0min 5sec - I start the application and it starts tracking automatically
0min 0sec - GPS module goes on (Diagnostics: GPS Receiver active, Module ID, Using GPS)
0min 5sec - GPS gets fix, location is trasmitted // Shouldn't the GPS go off now?
3min 0sec - GPS module goes off
3min 5sec - GPS module goes on (Diagnostics: GPS Receiver active, Module ID, Using GPS)
3min 10sec - GPS gets fix, location is trasmitted // Shouldn't the GPS go off now?

So, is there still something wrong in my settings or is there something else?

[jje]

SUBJECT:
GPS powersave function in Aspicore GSM Tracker v3.15 (released 17 Nov 2008)

RE: The above forum posting from a N96 user

BACKGROUND:
The GPS powersave behaviour seems to have slightly changed in Aspicore GSM Tracker v3.15 as a side-effect of another source code change.

The new software version 3.15 sends periodic data also, when the GPS says that the fix is not reliable.
This sending is controlled by the time period value in trigger settings. New version sends GPS data as such irrespective of the fix status, if the time period has elapsed.
The earlier software version sent only "accurate" position coordinates.

This software change was made, because one customer wanted to know his fleet were "alive" even if they were out of proper GPS signal coverage.

On the other hand, the GPS powersave gets activated only after a valid position has been sent to the server. Sending an invalid position (or plain satellite timestamp without latitude and longitude) is not sufficient to sleep the GPS module.

There are so many combinations in the application settings, that even a small software logic change seems to make a risk of unexpected side effects

SUGGESTED SOLUTION:

For the N96 user above I suggested the following new settings:
Trig1 / Time period, min: 0
Trig1 / Time period, sec: 10

With these settings GSM Tracker sends inaccurate GPS position at 10 seconds interval until it gets an accurate GPS position fix and finally after sending the accurate position sleeps the GPS module.

[porakone]

The trip I bought this software for, is coming closer and I started to look at this thing again after a while.

---
For the N96 user above I suggested the following new settings:
Trig1 / Time period, min: 0
Trig1 / Time period, sec: 10

With these settings GSM Tracker sends inaccurate GPS position at 10 seconds interval until it gets an accurate GPS position fix and finally after sending the accurate position sleeps the GPS module.
---

If I have to use the solution above to get the powersave to work, how do I set up the timing I want? Let's say I want it to send the location every 60 minutes, and I want it to try to get a fix for 10 minutes. And after the location is sent (or the fix wait 10min has passed), the gps unit should go to powersave.

[jje]

If I have to use the solution above to get the powersave to work, how do I set up the timing I want? Let's say I want it to send the location every 60 minutes, and I want it to try to get a fix for 10 minutes. And after the location is sent (or the fix wait 10min has passed), the gps unit should go to powersave.

Set GPS, Retry after, min to 60

and

GPS, max fix wait, min to 10

Keep the following time triggers:
Trig1 / Time period, min: 0
Trig1 / Time period, sec: 10

Note 1)
Regarding to the fix wait time, 10 minutes sounds quite long, but never mind. Usually, if you use AGPS, my experience is that it gets the fix within a minute or does not get it at all until the satellites become better visible. (Satellites move relatively slowly, they move approximately 30 degrees in an hour.)

Note 2)
AGPS requires a network connection, which consumes a little GPRS data. For some people this may be an issue if they are roaming. Plain GPS (without the A) does not consume data to get a fix.

Note 3)
To increase the probability of getting a real GPS fix with a weak satellite signal, check also that the positioning method "Network based" is disabled. (See FAQ #52 at http://www.aspicore.com/support/gsmtrckr/default.htm#n95ttff)

[porakone]

A short off-topic first. I don't seem to find the 'quote' button in this forum, only 'post reply'. You seem to be ale to use it but is it disabled for normal users of are my 10+ year old glasses worse than I thought..

Anyway..

>Set GPS, Retry after, min to 60
>GPS, max fix wait, min to 10
>Trig1 / Time period, min: 0
>Trig1 / Time period, sec: 10

This seems to work now, I can't figure out the logics in this but it works and that's enough 4 me.

>AGPS requires a network connection, which consumes a little GPRS data. For some people this may be an issue if they are roaming. Plain GPS (without the A) does not consume data to get a fix.

I'm aware of that. But as I will be using data transfer for other purposes too, I'll be buying me a '100mb roaming data pack' for the trip so that's not a problem.

>To increase the probability of getting a real GPS fix with a weak satellite signal, check also that the positioning method "Network based" is disabled.

Yes I found this out when I changed from N95 to N96 and the new phone seemed to take forever to get a fix.

As this problem is now solved, I have another question. It's the internet connection. As I will be sending the location quite rarely I was thinking that is there any way to 'turn off' the internet connection when it's not needed? I've noticed that especially while in 3G network, even the most idle connection seems to use quite a lot of battery.

[jje]

A short off-topic first. I don't seem to find the 'quote' button in this forum, only 'post reply'. You seem to be ale to use it but is it disabled for normal users of are my 10+ year old glasses worse than I thought..

Thanks for this feedback also. I must say I am not an expert with this forum software, but I think the 'quote' button should be visible for logged in users at the top right corner of the posting. I made a test user and did see the button. Sorry, if your account misses it for some strange reason.

As this problem is now solved, I have another question. It's the internet connection. As I will be sending the location quite rarely I was thinking that is there any way to 'turn off' the internet connection when it's not needed? I've noticed that especially while in 3G network, even the most idle connection seems to use quite a lot of battery.

Okay, as this has been asked a few times, we shall publish a new version, which turns off also the Internet connection soon after turning off the GPS. We want still to do some more testing before releasing it.

[jje]

As this problem is now solved, I have another question. It's the internet connection. As I will be sending the location quite rarely I was thinking that is there any way to 'turn off' the internet connection when it's not needed? I've noticed that especially while in 3G network, even the most idle connection seems to use quite a lot of battery.

Okay, as this has been asked a few times, we shall publish a new version, which turns off also the Internet connection soon after turning off the GPS. We want still to do some more testing before releasing it.

Now the new version 3.16 turns off also the Internet connection shortly after turning off the GPS, when running on the battery and the Powersave after fix has been turned on.

Another change is, that there is a new 2 minutes timeout for the GPS power, when running on the battery and the Powersave after fix has been turned on.
This timeout turns off the GPS two minutes after the fix, even if no data send trigger fired.

You can download the new version from here: http://www.aspicore.com/en/tuotteet_tracker.asp?tab=2&sub=2