NRF9160 GPS fix problem

RE: NRF9160 GPS fix problem

Martin Lesund — Wed, 14 Aug 2019 13:54:30 GMT

Hi Miro,

The network state must be in "power saving mode" (PSM) for the GPS to be active, as shown in the release notes for the v1.0.0 modem fw:

Support for simultaneous GNSS and LTE (M1 or NB1) system modes. GPS reception during
  LTE Power Saving Mode (PSM) active periods.

After sending data over the LTE network, you will remain active for a given time period afterward before going back to PSM.

The active time can be requested using this config:

https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/drivers/lte_link_control/Kconfig#L45

The default request is 1 minute, but by setting for instance "00000001" you request 2 second active time (see the 3gpp spec chapter reference for the definition of the GPRS timer 2).

Note: The PSM timeout uses GPRS Timer 3, which has a different bit definition than GPRS timer 2.

You can request intervals, but its the LTE network that sets it for you. To read your current settings, send these AT commands:

AT+CEREG=5
AT+CEREG?

The last two-bit patterns will then be the active time and TAU, as described here:

https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/nw_service/cereg_read.html

Remember that there will come modem firmware updates in the future that will optimize and add features, for more information about the roadmap please contact your Regional Sales Manager.
If you do not know who that is please send me a direct message on Devzone.

RE: NRF9160 GPS fix problem

MiroslavP — Wed, 14 Aug 2019 13:23:59 GMT

I'm use my external "Helix GNSS antenna", and I had a fixed position after ~20min minutes. With internal antenna I had a fixed position after ~2-3hour. And with external big RHCP antenna, I had fix GPS position after several minutes.

But I have on the same position other GPS module with my external Helix antenna, he has a fixed position in a few minutes.

You prototype board have problem with HW ? Or this is SW problem ?

RE: NRF9160 GPS fix problem

Martin Lesund — Mon, 12 Aug 2019 11:30:08 GMT

Hi Miro,

Please try to use the "Molex helix GNNS antenna" connected to the nRF9160DK and set the switch to the correct position.

(so not the internal antenna)

RE: NRF9160 GPS fix problem

MiroslavP — Mon, 12 Aug 2019 07:07:08 GMT

Hello Martin.

- Yes, switch position is on the internal antenna, and i'm use internal antenna. I'm use same antenna with U-Blox ZOE GNSS module, without GPS amplifier, and all is works.

This is my console output

***** Booting Zephyr OS v1.14.99-ncs2 *****
Flash region		Domain		Permissions
00 0x00000 0x08000 	Secure		rwxl
01 0x08000 0x10000 	Non-Secure	rwxl
02 0x10000 0x18000 	Non-Secure	rwxl
03 0x18000 0x20000 	Non-Secure	rwxl
04 0x20000 0x28000 	Non-Secure	rwxl
05 0x28000 0x30000 	Non-Secure	rwxl
06 0x30000 0x38000 	Non-Secure	rwxl
07 0x38000 0x40000 	Non-Secure	rwxl
08 0x40000 0x48000 	Non-Secure	rwxl
09 0x48000 0x50000 	Non-Secure	rwxl
10 0x50000 0x58000 	Non-Secure	rwxl
11 0x58000 0x60000 	Non-Secure	rwxl
12 0x60000 0x68000 	Non-Secure	rwxl
13 0x68000 0x70000 	Non-Secure	rwxl
14 0x70000 0x78000 	Non-Secure	rwxl
15 0x78000 0x80000 	Non-Secure	rwxl
16 0x80000 0x88000 	Non-Secure	rwxl
17 0x88000 0x90000 	Non-Secure	rwxl
18 0x90000 0x98000 	Non-Secure	rwxl
19 0x98000 0xa0000 	Non-Secure	rwxl
20 0xa0000 0xa8000 	Non-Secure	rwxl
21 0xa8000 0xb0000 	Non-Secure	rwxl
22 0xb0000 0xb8000 	Non-Secure	rwxl
23 0xb8000 0xc0000 	Non-Secure	rwxl
24 0xc0000 0xc8000 	Non-Secure	rwxl
25 0xc8000 0xd0000 	Non-Secure	rwxl
26 0xd0000 0xd8000 	Non-Secure	rwxl
27 0xd8000 0xe0000 	Non-Secure	rwxl
28 0xe0000 0xe8000 	Non-Secure	rwxl
29 0xe8000 0xf0000 	Non-Secure	rwxl
30 0xf0000 0xf8000 	Non-Secure	rwxl
31 0xf8000 0x100000 	Non-Secure	rwxl
Non-secure callable region 0 placed in flash region 0 with size 32.


SRAM region		Domain		Permissions
00 0x00000 0x02000	Secure		rwxl
01 0x02000 0x04000	Secure		rwxl
02 0x04000 0x06000	Secure		rwxl
03 0x06000 0x08000	Secure		rwxl
04 0x08000 0x0a000	Secure		rwxl
05 0x0a000 0x0c000	Secure		rwxl
06 0x0c000 0x0e000	Secure		rwxl
07 0x0e000 0x10000	Secure		rwxl
08 0x10000 0x12000	Non-Secure	rwxl
09 0x12000 0x14000	Non-Secure	rwxl
10 0x14000 0x16000	Non-Secure	rwxl
11 0x16000 0x18000	Non-Secure	rwxl
12 0x18000 0x1a000	Non-Secure	rwxl
13 0x1a000 0x1c000	Non-Secure	rwxl
14 0x1c000 0x1e000	Non-Secure	rwxl
15 0x1e000 0x20000	Non-Secure	rwxl
16 0x20000 0x22000	Non-Secure	rwxl
17 0x22000 0x24000	Non-Secure	rwxl
18 0x24000 0x26000	Non-Secure	rwxl
19 0x26000 0x28000	Non-Secure	rwxl
20 0x28000 0x2a000	Non-Secure	rwxl
21 0x2a000 0x2c000	Non-Secure	rwxl
22 0x2c000 0x2e000	Non-Secure	rwxl
23 0x2e000 0x30000	Non-Secure	rwxl
24 0x30000 0x32000	Non-Secure	rwxl
25 0x32000 0x34000	Non-Secure	rwxl
26 0x34000 0x36000	Non-Secure	rwxl
27 0x36000 0x38000	Non-Secure	rwxl
28 0x38000 0x3a000	Non-Secure	rwxl
29 0x3a000 0x3c000	Non-Secure	rwxl
30 0x3c000 0x3e000	Non-Secure	rwxl
31 0x3e000 0x40000	Non-Secure	rwxl

Peripheral		Domain		Status
00 NRF_P0		Non-Secure	OK
01 NRF_CLOCK		Non-Secure	OK
02 NRF_RTC1		Non-Secure	OK
03 NRF_NVMC		Non-Secure	OK
04 NRF_UARTE1		Non-Secure	OK
05 NRF_UARTE2		Secure		SKIP
06 NRF_TWIM2		Non-Secure	OK
07 NRF_SPIM3		Non-Secure	OK
08 NRF_TIMER0		Non-Secure	OK
09 NRF_TIMER1		Non-Secure	OK
10 NRF_TIMER2		Non-Secure	OK
11 NRF_SAADC		Non-Secure	OK
12 NRF_PWM0		Non-Secure	OK
13 NRF_PWM1		Non-Secure	OK
14 NRF_PWM2		Non-Secure	OK
15 NRF_PWM3		Non-Secure	OK
16 NRF_IPC		Non-Secure	OK
17 NRF_VMC		Non-Secure	OK
18 NRF_FPU		Non-Secure	OK
19 NRF_EGU1		Non-Secure	OK
20 NRF_EGU2		Non-Secure	OK
21 NRF_GPIOTE1		Non-Secure	OK

SPM: NS image at 0xc000
SPM: NS MSP at 0x20024748
SPM: NS reset vector at 0x13ae9
SPM: prepare to jump to Non-Secure image.
***** Booting Zephyr OS v1.14.99-ncs2 *****
Staring GPS application
Socket created
Getting GPS data...
[1;1H[2JTracking: 1 Using: 0 Unhealthy: 1
Seconds since last fix 0

Scanning [|] [1;1H[2JTracking: 1 Using: 0 Unhealthy: 1
Seconds since last fix 0

Scanning [/] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 1
Scanning [-] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 1

Scanning [\] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 2
Scanning [|] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 2

Scanning [/] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 3

Scanning [-] [1;1H[2JTracking: 0 Using: 0 Unhealthy: 0
Seconds since last fix 3

Scanning [\] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 4

Scanning [|] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 4

Scanning [/] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 5

Scanning [-] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 5
Scanning [\] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 6
Scanning [|] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 6
Scanning [/] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 7
Scanning [-] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 7

Scanning [\] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 8

Scanning [|] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 8

Scanning [/] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 9

Scanning [-] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 9

Scanning [\] [1;1H[2JTracking: 1 Using: 1 Unhealthy: 0
Seconds since last fix 10

RE: NRF9160 GPS fix problem

Martin Lesund — Thu, 08 Aug 2019 13:33:22 GMT

Hi Miro,

Could you please confirm that you have the switch to the 'CON' position when using the external antenna on the nRF91 DK?
Please try to place the antenna outside the window.
Please share any log output if this may fail.

RE: NRF9160 GPS fix problem

MiroslavP — Thu, 08 Aug 2019 11:20:29 GMT

Hi Martin.

Yes, I'm use same Molex helix GNNS antena. With external antena I have same problem

RE: NRF9160 GPS fix problem

Martin Lesund — Thu, 08 Aug 2019 11:14:21 GMT

Hi Miro,

Are you using the same GPS antenna which the other GPS module is using?

The GPS antenna on the nRF9160 DK may perform differently than the other GPS module.
I would highly recommend you to use an external antenna to improve the performance.

RE: NRF9160 GPS fix problem

MiroslavP — Thu, 08 Aug 2019 09:29:04 GMT

Hello Martin. Yes i know it. I have a board on the window. On the same position different GPS module is work

RE: NRF9160 GPS fix problem

Martin Lesund — Tue, 06 Aug 2019 08:50:20 GMT

Hi Miro,

From the GPS documentation:

GPS signals do not usually penetrate ceilings or other structures that well. Therefore, for best GPS performance, the DK should be placed on a flat surface in an open space outside, far from sources of interference and other structures that may block the signals from space.

From the GPS Tutorial:

"It can also be very practical to attach an external GPS antenna when doing development and test indoors. That allows you to put the GPS antenna near a window in order to see satellites."