L86 - 13 satellites in view - no fix after multiple minutes

fvquicke · March 11, 2020, 1:36pm

After enabling the device (cold start), we see multiple satellites in range (GPS and GLONASS). But after waiting more than 1 minute, we still do not have a fix.

Is it normal that we see 13 satellites but cannot get a fix?

We are not using EASY and according to the datasheet, a fix should be there in less than 35 seconds. We have to wait multiple minutes to get a fix. This is not normal I assume. How can we approve this?

Detailed logging:
Logging starts after having the device enabled for 3 minutes.
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 42
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 42/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 33/100
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 17/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Timer done, put device in deep sleep and wake-up in 5 secs, 43
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 34/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 44
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 15/100
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 40/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 40/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: Timer done, put device in deep sleep and wake-up in 5 secs, 45
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 23/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: PIN changed 22
app: Single tab detected
app: PIN changed 22
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Timer done, put device in deep sleep and wake-up in 5 secs, 46
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 21/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 47
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 21/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 1/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 48
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 18/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 11/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 10/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Timer done, put device in deep sleep and wake-up in 5 secs, 49
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 5/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 18/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: Timer done, put device in deep sleep and wake-up in 5 secs, 50
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 8/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 51
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 2/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: PIN changed 22
app: Single tab detected
app: PIN changed 22
app: PIN changed 22
app: Single tab detected
app: PIN changed 22
app: PIN changed 22
app: PIN changed 22
app: PIN changed 22
app: Single tab detected
app: PIN changed 22
app: PIN changed 22
app: PIN changed 22
app: PIN changed 22
app: Single tab detected
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: PIN changed 22
app: PIN changed 22
app: PIN changed 22
app: $xxVTG: speed kph =
app: PIN changed 22
app: Single tab detected
app: PIN changed 22
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 52
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 11/100
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 9/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 7/100
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0
app: GP
app: $xxGSV: satellites in view: 13
app: GL
app: $xxGSV: satellites in view: 8
app: GL
app: $xxGSV: satellites in view: 8
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGSV: satellites in view: 13
app: Not recognized line 0, $GPTXT,01,01,02,ANTSTATUS=OPEN*2B
app: $xxVTG: speed kph =
app: GP
app: $xxGSV: satellites in view: 13
app: GP
app: $xxGLL: raw coordinates and speed: (0/0,0/0)
app: Timer done, put device in deep sleep and wake-up in 5 secs, 53
app: GP
app: $xxRMC: raw coordinates and speed: (0/0,0/0) 27/100
app: $xxVTG: speed kph =
app: GP
app: $xxGGA: fix quality: 0

sammy-Q · March 12, 2020, 1:33am

Please check SNR value in GSV sentence, there should be 4 satellites with at least 33 dB to get a fast fix.
Please provide me the original NMEA log with GSV/RMC sentences.

kiku · March 17, 2020, 12:26pm

I also meet similar issue in L76. Even though the GSV sentences have several satellites with azimuth and elevation, but their SNRs are still NULL.

What are the possible reasons for SNR to be NULL?

When such problem happens, how to recover the GNSS module?

sammy-Q · March 18, 2020, 1:14am

There may be some reasons:

Poor antenna performance.
Hardware design issue.
Environment.

I suggest to send email to support@quectel.com, and tell us the country/company name, then we will asign local FAE to support this issue, thanks!

askpatrickw · March 26, 2020, 8:28pm

You should reach out to PyCom. their PyTrack board definitely has this issue. Another user and I were discussing this today.

The board itself looks like this… (antenna down in the bottom right)

Z
More details: https://docs.pycom.io/datasheets/boards/pytrack/

BUT, when you put their MicroPython board on top, you also have a WiFi\BLE antenna near it. Atleast on the GPY board I have. Their other boards have over radios. Anyway… potential client who might need assistance.

sammy-Q · March 27, 2020, 1:50am

We highly recommend to put GNSS antenna on top of the board and pointing to open sky.
Has PyCom sent his design files to support@quectel.com for review? We need review the hardware design first.