Hi, all:
I use 9160DK to test GPS standalone mode as follow steps with AT command example：
Approach 1:
1、set ”AT+CFUN=0“ to power off mode;
2、set "AT%XSYSTEMMODE=1,1,1,0" to configure the system mode where I have enable the LTE on, NBIOT on, GNSS ON and no preference
3、then set “AT+CFUN=1” to full functionality power on the mode；
4. AT#XGPS=1,0,0,0
As In above AT command sequence I can see 6-7 satellites as shown below but GPS reading does not Fix in long time
[00:02:22.031,524] <dbg> slm_gnss: on_gnss_evt_pvt: SV:194 sig: 3 c/n0: 386 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.042,114] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 27 sig: 1 c/n0: 390 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.052,703] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 9 sig: 1 c/n0: 340 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.063,293] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 16 sig: 1 c/n0: 349 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.073,883] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 7 sig: 1 c/n0: 315 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.084,472] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 8 sig: 1 c/n0: 245 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.095,062] <dbg> slm_gnss: on_gnss_evt_pvt: SV: 17 sig: 1 c/n0: 248 el: 0 az: 0 in-fix: 0 unhealthy: 0
[00:02:22.105,682] <dbg> slm_gnss: on_gnss_evt_nmea: $GPGGA,000221.53,,,,,0,,99.99,,M,,M,,*61
[00:02:22.114,807] <dbg> slm_gnss: on_gnss_evt_nmea: $GPGLL,,,,,000221.53,V,N*4D
[00:02:22.122,833] <dbg> slm_gnss: on_gnss_evt_nmea: $GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,1*2D
[00:02:22.132,415] <dbg> slm_gnss: on_gnss_evt_nmea: $GPGSV,2,1,7,7,,,32,8,,,25,9,,,34,16,,,35,1*66
[00:02:22.142,059] <dbg> slm_gnss: on_gnss_evt_nmea: $GPGSV,2,2,7,17,,,25,27,,,39,194,,,39,1*6B
[00:02:22.151,397] <dbg> slm_gnss: on_gnss_evt_nmea: $GPRMC,000221.53,V,,,,,,,060180,,,N,V*0F
My observation is that when I change the SYSTEMMODE setting and use below AT command sequence then I got the GPS reading within in 2 minutes and GPS coordinate is fixed immediate.
Approach 2:
1. AT+CFUN=0
2. AT%XSYSTEMMODE=0,0,1,0 , here LTEM and NBIOT off and Only GNSS enable
3. AT+CFUN=31, GNSS is activated.
4. AT#XGPS=1,0,0,0
My Query: What is the wrong with Approach 1 where we are enable LTM and GNSS both and set the modem in full functional mode. We got the satellite enough but GPS reading does not Fixed.
Please guide me on this, is my approach is wrong or missing something?
Thanks
