GNSS acquisition rate

IoT Modules WP Series
1

Hello I’m having issues with getting the GNSS fix when setting an acquisition rate lower than 1000 ms.
I’m using a WP7607 module.

Setting the same acquisition rate to a WP7502 works like a charm.

To be more specific on the issue on the WP7607 module:
After setting the acquisition rate and starting the gnss service (gnss start) I monitor the ‘gnss get posInfo’ and I note that the position is indeed correctly computed, but the GPS time is not and the fix state shows that there is no fix.

I’m wondering why this is not working on the WP7607, while it works on the WP7502.

Also, I’m increasing the acquisition rate since I notices an improvement on the accuracy of the GPS position.

2

Hi parmeggianig

Could you share your testing script, setup?

3

Hello,

To test this I’m executing the following commands:

root@swi-mdm9x28:~# gnss set acqRate 100
Success!
root@swi-mdm9x28:~# gnss start
Success!
root@swi-mdm9x28:~# watch -n 1 -d "gnss get posInfo"

I noticed that this issue appears only when using Legato 18.08.0, while if I revert back to the default 18.03.0 the problem disappears. Is the new legato not compatible with the gnss module on the WP76XX?

4

Hello,

I wanted to let you know that this issue appears also when installing a clean Release 10.1 .cwe file (https://source.sierrawireless.com/resources/airprime/software/wp76xx/wp76xx-firmware-release-10,-d-,1/)
which comes with legato 18.06.3.
Therefore I’m assuming this is a bug that has been introduced between legato 18.03.0 and 18.06.3.

Are you able to reproduce the bug?
Will you assist me in solving this issue?

Thanks
Giacomo

5

Hi Giacomo

Sorry, In before I try GNSS with AT-command only and don’t know how to use Linux.
So I haven’t try your script.

Is “acqRate” be function in Linux?
Could you share more information?

Do you got a NMEA data not enough acquisition rate?

Of course I am not expert in GNSS & Linux, but I tried GNSS testing in before. And seem everything pass.
I wish to know more your problem and try in my side via AT-command & NMEA stream data.

BR