GNSS sample vs Location sample

[flau]

Hi Everyone,

I have a custom board with a nRF9160.  I have updated the firmware to 1.3.3.  I am using SDK 1.9.1.  I found that the board works well with the GNSS sample from the SDK.  The board can typically see 10-11 satellites, track 5-8 of them and give me a good location.  However, when I run the Location sample from the SDK, it only sees1-2 satellites when I placed the board at exactly the same location.  I even put 2 boards side by side, 1 running the GNSS samples, the other running the Location sample.  The GNSS sample always perform well.  Are there any different between the GNSS sample and the Location sample?  I would like to obtain the same good result with the Location sample as with the GNSS sample.  Are there anything I have to change to achieve that?  Many thanks.

Regards,

Floyd

[flau]

I am very frustrated now.  With the Location sample, my board can see and track 11-12 satellites, but still no fix.  What determines a fix and provide a location?

[00:08:10.960,052] <dbg> location.method_gnss_print_pvt: Tracked satellites: 11, fix valid: false
[00:08:10.970,214] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.7, in fix: 0, unhealthy: 0
[00:08:10.980,926] <dbg> location.method_gnss_print_pvt: PRN: 20, C/N0: 24.5, in fix: 0, unhealthy: 0
[00:08:10.991,638] <dbg> location.method_gnss_print_pvt: PRN: 9, C/N0: 24.3, in fix: 0, unhealthy: 0
[00:08:11.002,319] <dbg> location.method_gnss_print_pvt: PRN: 6, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:11.013,031] <dbg> location.method_gnss_print_pvt: PRN: 27, C/N0: 24.5, in fix: 0, unhealthy: 0
[00:08:11.023,742] <dbg> location.method_gnss_print_pvt: PRN: 19, C/N0: 24.7, in fix: 0, unhealthy: 0
[00:08:11.034,454] <dbg> location.method_gnss_print_pvt: PRN: 14, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:11.045,166] <dbg> location.method_gnss_print_pvt: PRN: 10, C/N0: 23.9, in fix: 0, unhealthy: 0
[00:08:11.055,877] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 24.2, in fix: 0, unhealthy: 0
[00:08:11.066,589] <dbg> location.method_gnss_print_pvt: PRN: 4, C/N0: 24.3, in fix: 0, unhealthy: 0
[00:08:11.077,301] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:12.077,301] <dbg> location.method_gnss_print_pvt: Tracked satellites: 12, fix valid: false
[00:08:12.087,463] <dbg> location.method_gnss_print_pvt: PRN: 12, C/N0: 26.9, in fix: 0, unhealthy: 0
[00:08:12.098,175] <dbg> location.method_gnss_print_pvt: PRN: 20, C/N0: 24.2, in fix: 0, unhealthy: 0
[00:08:12.108,886] <dbg> location.method_gnss_print_pvt: PRN: 9, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:12.119,598] <dbg> location.method_gnss_print_pvt: PRN: 6, C/N0: 24.8, in fix: 0, unhealthy: 0
[00:08:12.130,310] <dbg> location.method_gnss_print_pvt: PRN: 27, C/N0: 24.6, in fix: 0, unhealthy: 0
[00:08:12.140,991] <dbg> location.method_gnss_print_pvt: PRN: 19, C/N0: 24.6, in fix: 0, unhealthy: 0
[00:08:12.151,702] <dbg> location.method_gnss_print_pvt: PRN: 14, C/N0: 24.1, in fix: 0, unhealthy: 0
[00:08:12.162,445] <dbg> location.method_gnss_print_pvt: PRN: 10, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:12.173,156] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 24.2, in fix: 0, unhealthy: 0
[00:08:12.183,868] <dbg> location.method_gnss_print_pvt: PRN: 4, C/N0: 24.1, in fix: 0, unhealthy: 0
[00:08:12.194,549] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 24.0, in fix: 0, unhealthy: 0
[00:08:12.205,291] <dbg> location.method_gnss_print_pvt: PRN: 24, C/N0: 24.9, in fix: 0, unhealthy: 0
[00:08:13.080,871] <dbg> location.method_gnss_print_pvt: Tracked satellites: 12, fix valid: false
[00:08:13.091,033] <dbg> location.method_gnss_print_pvt: PRN: 12, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:13.101,745] <dbg> location.method_gnss_print_pvt: PRN: 18, C/N0: 26.9, in fix: 0, unhealthy: 0
[00:08:13.112,457] <dbg> location.method_gnss_print_pvt: PRN: 9, C/N0: 24.5, in fix: 0, unhealthy: 0
[00:08:13.123,168] <dbg> location.method_gnss_print_pvt: PRN: 7, C/N0: 25.5, in fix: 0, unhealthy: 0
[00:08:13.133,880] <dbg> location.method_gnss_print_pvt: PRN: 27, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:13.144,592] <dbg> location.method_gnss_print_pvt: PRN: 19, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:13.155,303] <dbg> location.method_gnss_print_pvt: PRN: 14, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:08:13.166,015] <dbg> location.method_gnss_print_pvt: PRN: 10, C/N0: 24.8, in fix: 0, unhealthy: 0
[00:08:13.176,727] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 24.5, in fix: 0, unhealthy: 0
[00:08:13.187,438] <dbg> location.method_gnss_print_pvt: PRN: 4, C/N0: 24.1, in fix: 0, unhealthy: 0
[00:08:13.198,120] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 24.1, in fix: 0, unhealthy: 0
[00:08:13.208,831] <dbg> location.method_gnss_print_pvt: PRN: 24, C/N0: 24.2, in fix: 0, unhealthy: 0

PLEASE HELP!!

[flau]

I reverted the nRF9160 firmware from 1.3.3 to 1.3.2.  There is no difference.  I reverted again to 1.3.1.  There is no difference either.  The board still tracks 11-12 satellites but 0 fix.  I tried another board and the result is the same.  SDK is 1.9.1.

[Øyvind]

Can you provide some information on where you are doing you testing, i.e. the conditions around your device?

Do you have an nRF9160 DK or Thingy:91 to test with as well?

[flau]

All tests were done by placing the devices on the ledge of a 6' x 20' window where there is no building outside blocking the sky.  

I have a nRF9160 DK.  But that won't be a fair comparison because the DK has a much better GPS antenna.  I used to have a Thingy91.  But it is dead now.  The power supply circuitry seems to be dead.  Anyway, I can try with the DK and give you some results.  Please stay tuned.  

BTW, Happy New Year to all of you.

[flau]

With the nRF9160 DK at the window ledge, I am getting similar results.

[00:29:30.498,596] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false
[00:29:30.508,636] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 31.3, in fix: 0, unhealthy: 0
[00:29:30.519,348] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 34.2, in fix: 0, unhealthy: 0
[00:29:30.530,029] <dbg> location.method_gnss_print_pvt: PRN: 22, C/N0: 38.3, in fix: 0, unhealthy: 0
[00:29:30.540,740] <dbg> location.method_gnss_print_pvt: PRN: 32, C/N0: 31.4, in fix: 0, unhealthy: 0
[00:29:30.551,422] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.5, in fix: 0, unhealthy: 0
[00:29:31.616,485] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false
[00:29:31.626,525] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 31.3, in fix: 0, unhealthy: 0
[00:29:31.637,207] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 34.0, in fix: 0, unhealthy: 0
[00:29:31.647,918] <dbg> location.method_gnss_print_pvt: PRN: 22, C/N0: 38.6, in fix: 0, unhealthy: 0
[00:29:31.658,599] <dbg> location.method_gnss_print_pvt: PRN: 32, C/N0: 31.4, in fix: 0, unhealthy: 0
[00:29:31.669,311] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.9, in fix: 0, unhealthy: 0
[00:29:32.617,858] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false
[00:29:32.627,929] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 31.1, in fix: 0, unhealthy: 0
[00:29:32.638,610] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 34.3, in fix: 0, unhealthy: 0
[00:29:32.649,322] <dbg> location.method_gnss_print_pvt: PRN: 22, C/N0: 38.6, in fix: 0, unhealthy: 0
[00:29:32.660,003] <dbg> location.method_gnss_print_pvt: PRN: 32, C/N0: 31.3, in fix: 0, unhealthy: 0
[00:29:32.670,715] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.1, in fix: 0, unhealthy: 0
[00:29:33.618,377] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false
[00:29:33.628,448] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 31.4, in fix: 0, unhealthy: 0
[00:29:33.639,129] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 34.3, in fix: 0, unhealthy: 0
[00:29:33.649,841] <dbg> location.method_gnss_print_pvt: PRN: 22, C/N0: 38.8, in fix: 0, unhealthy: 0
[00:29:33.660,552] <dbg> location.method_gnss_print_pvt: PRN: 32, C/N0: 31.1, in fix: 0, unhealthy: 0
[00:29:33.671,264] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.6, in fix: 0, unhealthy: 0
[00:29:34.618,743] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false
[00:29:34.628,814] <dbg> location.method_gnss_print_pvt: PRN: 31, C/N0: 31.4, in fix: 0, unhealthy: 0
[00:29:34.639,526] <dbg> location.method_gnss_print_pvt: PRN: 25, C/N0: 34.6, in fix: 0, unhealthy: 0
[00:29:34.650,207] <dbg> location.method_gnss_print_pvt: PRN: 22, C/N0: 38.8, in fix: 0, unhealthy: 0
[00:29:34.660,919] <dbg> location.method_gnss_print_pvt: PRN: 32, C/N0: 31.0, in fix: 0, unhealthy: 0
[00:29:34.671,630] <dbg> location.method_gnss_print_pvt: PRN: 26, C/N0: 24.4, in fix: 0, unhealthy: 0
[00:29:35.618,286] <dbg> location.method_gnss_print_pvt: Tracked satellites: 5, fix valid: false

The DK has higher C/N0 comparing with the Ignion Trio antenna.  But other than that, no big difference.