Number of satellites and signal after a long time without GPS fix

RE: Number of satellites and signal after a long time without GPS fix

mackz — Fri, 06 Feb 2026 12:42:16 GMT

Did you get any answer to this issue?

RE: Number of satellites and signal after a long time without GPS fix

Michal — Fri, 16 May 2025 13:00:18 GMT

Thank you. I wonder, what happens when the device is left outside for a longer time? Or if it's inside for much shorter, lets say a few hours maybe?

RE: Number of satellites and signal after a long time without GPS fix

GoncaloS — Mon, 12 May 2025 11:34:27 GMT

Hello,

I am using external GPS antenna with integrated LNA.
I set the following configurations in prj.conf file:

CONFIG_MODEM_ANTENNA_GNSS_EXTERNAL=y
CONFIG_MODEM_ANTENNA_GNSS_ONBOARD=n
CONFIG_MODEM_ANTENNA_AT_COEX0="AT%XCOEX0"

I don't change the code between reboots.

Thanks,
GoncaloS

RE: Number of satellites and signal after a long time without GPS fix

Michal — Fri, 09 May 2025 21:59:18 GMT

What kind of external GPS antenna are you using? Does it have an integrated LNA?

When using external antenna you also have to disable the onboard LNA to avoid interferrence.

That can be done using the AT%COEX0 AT command.

Best regards,

Michal

RE: Number of satellites and signal after a long time without GPS fix

Michal — Wed, 07 May 2025 16:14:13 GMT

Sorry for the delay, I will try to provide you with an update or at least some suggestions what to possibly test this week.

Best regards,

Michal

RE: Number of satellites and signal after a long time without GPS fix

GoncaloS — Mon, 28 Apr 2025 10:02:07 GMT

Hello Michal,

Any updates on this topic?

Thanks,
GoncaloS

RE: Number of satellites and signal after a long time without GPS fix

GoncaloS — Tue, 15 Apr 2025 22:01:53 GMT

Hello Michal,

Thank you for your reply. I look forward to it.

Best regards,
GoncaloS

RE: Number of satellites and signal after a long time without GPS fix

Michal — Tue, 15 Apr 2025 21:56:39 GMT

Thank you for the logs.

I'm not sure if that will provide enough information, but I am looking into it and I will let you know when I'll have more information.

We are unfortunately at the start of the Easter holiday here in Norway, so I may not be able to get back to you before next week.

Best regards,

Michal

RE: Number of satellites and signal after a long time without GPS fix

GoncaloS — Mon, 14 Apr 2025 11:04:19 GMT

Hello,

I only have logs with number and signal of satellites at each acquisition period (in my case, I used 6 minutes). In this example, it's possible to see the moment when GNSS is no longer able to fix the position after a long time without fix with some satellites.

[17 days, 13:31:38] GNSS_SEARCH
[17 days, 13:32:43] Satellites Power: 
[17 days, 13:32:43] sv: 11, cn0: 229
[17 days, 13:32:43] sv: 3, cn0: 228
[17 days, 13:32:43] sv: 10, cn0: 229
[17 days, 13:32:43] sv: 201, cn0: 226
[17 days, 13:32:43] sv: 26, cn0: 244
[17 days, 13:32:43] sv: 16, cn0: 244
[17 days, 13:32:43] sv: 29, cn0: 240
[17 days, 13:32:43] sv: 9, cn0: 231
[17 days, 13:32:43] sv: 25, cn0: 230
[17 days, 13:32:43] sv: 4, cn0: 330
[17 days, 13:32:43] sv: 20, cn0: 224
[17 days, 13:32:43] sv: 27, cn0: 230
[17 days, 13:32:43] GNSS_SLEEP

[17 days, 13:37:38] GNSS_SEARCH
[17 days, 13:38:43] Satellites Power: 
[17 days, 13:38:43] sv: 24, cn0: 200
[17 days, 13:38:43] sv: 20, cn0: 120
[17 days, 13:38:43] sv: 4, cn0: 120
[17 days, 13:38:43] sv: 5, cn0: 120
[17 days, 13:38:43] sv: 18, cn0: 120
[17 days, 13:38:43] sv: 7, cn0: 120
[17 days, 13:38:43] sv: 9, cn0: 120
[17 days, 13:38:43] sv: 26, cn0: 120
[17 days, 13:38:43] sv: 28, cn0: 120
[17 days, 13:38:43] sv: 31, cn0: 120
[17 days, 13:38:43] sv: 25, cn0: 120
[17 days, 13:38:43] sv: 23, cn0: 120
[17 days, 13:38:43] GNSS_SLEEP

[17 days, 13:43:38] GNSS_SEARCH
[17 days, 13:44:43] Satellites Power: 
[17 days, 13:44:43] sv: 12, cn0: 224
[17 days, 13:44:43] sv: 11, cn0: 229
[17 days, 13:44:43] sv: 10, cn0: 228
[17 days, 13:44:43] sv: 8, cn0: 235
[17 days, 13:44:43] sv: 15, cn0: 231
[17 days, 13:44:43] sv: 25, cn0: 226
[17 days, 13:44:43] sv: 9, cn0: 413
[17 days, 13:44:43] sv: 3, cn0: 230
[17 days, 13:44:43] sv: 26, cn0: 232
[17 days, 13:44:43] sv: 28, cn0: 240
[17 days, 13:44:43] sv: 16, cn0: 228
[17 days, 13:44:43] sv: 31, cn0: 228
[17 days, 13:44:43] GNSS_SLEEP

[17 days, 13:49:38] GNSS_SEARCH
[17 days, 13:50:43] Satellites Power: 
[17 days, 13:50:43] GNSS_SLEEP

[17 days, 13:55:38] GNSS_SEARCH
[17 days, 13:56:43] Satellites Power: 
[17 days, 13:56:43] sv: 15, cn0: 0
[17 days, 13:56:43] GNSS_SLEEP

[17 days, 14:01:38] GNSS_SEARCH
[17 days, 14:02:43] Satellites Power: 
[17 days, 14:02:43] GNSS_SLEEP

[17 days, 14:07:38] GNSS_SEARCH
[17 days, 14:08:43] Satellites Power: 
[17 days, 14:08:43] GNSS_SLEEP

[17 days, 14:13:38] GNSS_SEARCH
[17 days, 14:14:43] Satellites Power: 
[17 days, 14:14:43] sv: 201, cn0: 0
[17 days, 14:14:43] GNSS_SLEEP

(Past some time)

[17 days, 15:13:38] GNSS_SEARCH
[17 days, 15:14:43] Satellites Power: 
[17 days, 15:14:43] GNSS_SLEEP

[17 days, 15:19:38] GNSS_SEARCH
[17 days, 15:20:43] Satellites Power: 
[17 days, 15:20:43] GNSS_SLEEP

[17 days, 15:25:38] GNSS_SEARCH
[17 days, 15:26:43] Satellites Power: 
[17 days, 15:26:43] GNSS_SLEEP

[17 days, 15:31:38] GNSS_SEARCH
[17 days, 15:32:43] Satellites Power: 
[17 days, 15:32:43] sv: 7, cn0: 0
[17 days, 15:32:43] GNSS_SLEEP

[17 days, 15:37:38] GNSS_SEARCH
[17 days, 15:38:43] Satellites Power: 
[17 days, 15:38:43] GNSS_SLEEP

After reset device (the device was located in the open street):

[0 days, 00:00:05] GNSS_SEARCH
[0 days, 00:00:05] Enable GNSS Timer and timeout GNSS
[0 days, 00:01:10] Satellites Power: 
[0 days, 00:01:10] sv: 27, cn0: 0
[0 days, 00:01:10] GNSS_SLEEP

[0 days, 00:06:05] GNSS_SEARCH
[0 days, 00:07:10] Satellites Power: 
[0 days, 00:07:10] GNSS_SLEEP

[0 days, 00:12:05] GNSS_SEARCH
[0 days, 00:13:10] Satellites Power: 
[0 days, 00:13:10] GNSS_SLEEP

[0 days, 00:18:05] GNSS_SEARCH
[0 days, 00:19:10] Satellites Power: 
[0 days, 00:19:10] sv: 31, cn0: 180
[0 days, 00:19:10] GNSS_SLEEP

[0 days, 00:24:05] GNSS_SEARCH
[0 days, 00:25:10] Satellites Power: 
[0 days, 00:25:10] GNSS_SLEEP

[0 days, 00:30:05] GNSS_SEARCH
[0 days, 00:31:10] Satellites Power: 
[0 days, 00:31:10] sv: 29, cn0: 230
[0 days, 00:31:10] GNSS_SLEEP

[0 days, 00:36:05] GNSS_SEARCH
[0 days, 00:37:10] Satellites Power: 
[0 days, 00:37:10] GNSS_SLEEP

[0 days, 00:42:05] GNSS_SEARCH
[0 days, 00:43:10] Satellites Power: 
[0 days, 00:43:10] sv: 26, cn0: 220
[0 days, 00:43:10] GNSS_SLEEP

You can reproduce this problem by configuring the GNSS as a single fix with an acquisition period, and leaving the board in a build without a GPS fix for ~2 days. Then take the board for street and check the satellite number and signal.

Thanks,
GoncaloS

RE: Number of satellites and signal after a long time without GPS fix

Michal — Wed, 09 Apr 2025 22:01:39 GMT

Hello GoncaloS,

Do you have any logs of those issues by chance?

Best reagrds,

Michal