EM7565 - GNSS errors

IoT Modules MC/EM Series
1

Hi,

Modem details:

Manufacturer: Sierra Wireless, Incorporated
Model: EM7565
Revision: SWI9X50C_01.09.04.00 6d3218 jenkins 2019/02/26 20:33:22

GPS NMEA details set:
AT!GPSNMEASENTENCE=C9FDF

Which means:

  • Enable all GP* sentences
  • Enable all GL* sentences
  • Enable all GN* sentences
  • Enable all GA* sentences

Errors seen:

  • Speed is always 0.0, no matter if there is movement or not. Applies to all RMC and VTG sentences.
  • Multiple GNGSA sentences are being produced. There are too many, and the final one contains an invalid field just before the CRC
  • Enabling GPDTM does not produce this sentence at all
  • Missing support for ZDA sentences (Time)

Here is output from the device:

$GLGSV,3,1,09,74,35,040,29,67,59,314,16,66,60,139,77,47,206,17F
$GLGSV,3,2,09,76,70,054,75,19,037,65,00,137,84,12,000,170
$GLGSV,3,3,09,83,07,306,148
$GPGSV,3,1,10,05,49,202,29,08,09,036,21,13,71,295,31,15,35,291,31,161
$GPGSV,3,2,10,21,12,312,21,28,46,125,35,30,52,066,44,07,19,061,163
$GPGSV,3,3,10,20,27,02,004,154
$GPGGA,171546.00,5114.148365,N,00312.975149,E,1,05,1.4,16.9,M,47.0,M,5A
$GAGGA,171546.00,5114.148365,N,00312.975149,E,1,00,1.4,16.9,M,47.0,M,4E
$GNGNS,171546.00,5114.148365,N,00312.975149,E,AAN,06,1.4,16.9,47.0,V59
$GPVTG,253.4,T,255.6,M,0.0,N,0.0,K,A27
$GAVTG,253.4,T,255.6,M,0.0,N,0.0,K,A36
$GPRMC,171546.00,A,5114.148365,N,00312.975149,E,0.0,253.4,301019,2.2,W,A,V5C
$GARMC,171546.00,A,5114.148365,N,00312.975149,E,0.0,253.4,301019,2.2,W,A,V4D
$GPGSA,A,2,05,13,15,28,30,1.7,1.4,1.0,126
$GAGSA,A,1,23
$GNGSA,A,2,05,13,15,28,30,1.7,1.4,1.0,138
$GNGSA,A,2,74,1.7,1.4,1.0,232
$GNGSA,A,2,1.7,1.4,1.02F
$GNGSA,A,2,1.7,1.4,1.02F
$GNGSA,A,2,1.7,1.4,1.0,330
$GLGSV,3,1,09,74,35,040,29,67,59,314,16,66,60,139,77,47,206,17F
$GLGSV,3,2,09,76,70,054,75,19,037,65,00,137,84,12,000,170
$GLGSV,3,3,09,83,07,306,148
$GPGSV,3,1,10,05,49,202,29,08,09,036,21,13,71,295,31,15,35,291,31,161
$GPGSV,3,2,10,21,12,312,21,28,46,125,35,30,52,066,44,07,19,061,163
$GPGSV,3,3,10,20,27,02,004,154
$GPGGA,171547.00,5114.148364,N,00312.975147,E,1,05,1.4,16.9,M,47.0,M,54
$GAGGA,171547.00,5114.148364,N,00312.975147,E,1,00,1.4,16.9,M,47.0,M,40
$GNGNS,171547.00,5114.148364,N,00312.975147,E,AAN,06,1.4,16.9,47.0,V57
$GPVTG,253.4,T,255.6,M,0.0,N,0.0,K,A27
$GAVTG,253.4,T,255.6,M,0.0,N,0.0,K,A36
$GPRMC,171547.00,A,5114.148364,N,00312.975147,E,0.0,253.4,301019,2.2,W,A,V52
$GARMC,171547.00,A,5114.148364,N,00312.975147,E,0.0,253.4,301019,2.2,W,A,V43
$GPGSA,A,2,05,13,15,28,30,1.7,1.4,1.0,126
$GAGSA,A,1,23
$GNGSA,A,2,05,13,15,28,30,1.7,1.4,1.0,138
$GNGSA,A,2,74,1.7,1.4,1.0,232
$GNGSA,A,2,1.7,1.4,1.02F
$GNGSA,A,2,1.7,1.4,1.02F
$GNGSA,A,2,1.7,1.4,1.0,330

2

Hi,
1st error: I cannot check your speed error because my condition doesn’t allow to test speed.
2nd & 3rd errors: I’ve not seen any errors as yours
4th error: The document doesn’t state that ZDA sentences are supported. Maybe this is a future improvement

Here is output from the device:
$GPGGA,082330.00,0,42
$GAGGA,082330.00,0,53
$GNGNS,082330.00,NNN,39
$GPVTG,T,M,N,K,N2C
$GAVTG,T,M,N,K,N3D
$GPRMC,V,N53
$GARMC,V,N42
$GPGSA,A,1,32
$GAGSA,A,1,23
$GNGSA,A,1,2C
$GAGSV,2,1,07,04,19,320,36,01,65,154,12,32,248,19,38,023,773
$GAGSV,2,2,07,21,42,053,31,21,201,33,24,191,74A
$GPGSV,3,1,11,10,59,002,12,20,060,14,21,305,20,71,087,165
$GPGSV,3,2,11,21,35,189,24,04,036,25,47,104,26,08,201,169
$GPGSV,3,3,11,29,02,144,31,45,244,32,30,333,15C
$GPGGA,082331.00,0,43
$GAGGA,082331.00,0,52
$GNGNS,082331.00,NNN,38
$GPVTG,T,M,N,K,N2C
$GAVTG,T,M,N,K,N3D
$GPRMC,V,N53
$GARMC,V,N42
$GPGSA,A,1,32
$GAGSA,A,1,23
$GNGSA,A,1,2C
$GAGSV,2,1,07,04,19,320,36,01,65,154,12,32,248,19,38,023,773
$GAGSV,2,2,07,21,42,053,31,21,201,33,24,191,74A
$GPGSV,3,1,11,10,59,002,12,20,060,14,21,305,20,71,087,165
$GPGSV,3,2,11,21,35,189,24,04,036,25,47,104,26,08,201,169
$GPGSV,3,3,11,29,02,144,31,45,244,32,30,333,15C
$GPGGA,082332.00,0,40
$GAGGA,082332.00,0,51
$GNGNS,082332.00,NNN,3B
$GPVTG,T,M,N,K,N2C
$GAVTG,T,M,N,K,N3D
$GPRMC,V,N53
$GARMC,V,N42
$GPGSA,A,1,32
$GAGSA,A,1,23
$GNGSA,A,1,2C
$GAGSV,2,1,07,04,19,320,35,01,65,154,12,32,248,19,38,023,770
$GAGSV,2,2,07,21,42,053,31,21,201,33,24,191,74A
$GPGSV,3,1,11,10,59,002,38,14,21,305,35,20,71,087,26,32,30,333,37,16E
$GPGSV,3,2,11,12,20,060,21,35,189,24,04,036,25,47,104,161
$GPGSV,3,3,11,26,08,201,29,02,144,31,45,244,152
$GPGGA,082332.44,0,40
$GAGGA,082332.44,0,51
$GNGNS,082332.44,NNN,3B
$GAGNS,082332.44,NNN,34
$GPVTG,T,M,N,K,N2C
$GAVTG,T,M,N,K,N3D
$GPRMC,V,N53
$GARMC,V,N42
$GPGSA,A,1,32
$GAGSA,A,1,23
$GNGSA,A,1,2C
$GPGGA,082333.00,0,41
$GAGGA,082333.00,0,50
$GNGNS,082333.00,NNN,3A
$GAGNS,082333.00,NNN,35
$GPVTG,T,M,N,K,N2C
$GAVTG,T,M,N,K,N3D
$GPRMC,V,N53
$GARMC,V,N42
$GPGSA,A,1,32
$GAGSA,A,1,23
$GNGSA,A,1,2C
$GPGSV,3,1,11,10,59,002,38,12,20,059,21,14,21,305,35,20,71,087,26,165
$GPGSV,3,2,11,24,04,036,28,25,47,104,24,32,30,333,36,21,35,189,16E
$GPGSV,3,3,11,26,08,201,29,02,144,31,45,244,152
$GAGSV,2,1,07,04,19,320,36,01,65,154,12,32,248,19,38,023,773
$GAGSV,2,2,07,21,42,053,31,21,201,33,24,191,74A
$GPGGA,082334.00,1051.395595,N,10637.873009,E,1,05,2.0,24.5,M,-1.0,M,4F
$GPDTM,P90,0000.000009,S,00000.000002,W,0.998,W8451
$GAGGA,082334.00,1051.395595,N,10637.873009,E,1,01,2.0,24.5,M,-1.0,M,5A
$GNGNS,082334.00,1051.395595,N,10637.873009,E,ANA,06,2.0,24.5,-1.0,V4C
$GAGNS,082334.00,1051.395595,N,10637.873009,E,NNA,01,2.0,24.5,-1.0,V4B
$GPVTG,0.0,T,0.9,M,0.0,N,0.0,K,A2A
$GAVTG,0.0,T,0.9,M,0.0,N,0.0,K,A3B
$GPRMC,082334.00,A,1051.395595,N,10637.873009,E,0.0,0.0,041119,0.9,W,A,V53
$GARMC,082334.00,A,1051.395595,N,10637.873009,E,0.0,0.0,041119,0.9,W,A,V42
$GPGSA,A,2,10,12,20,24,32,2.2,2.0,0.9,122
$GAGSA,A,2,04,2.2,2.0,0.9,332
$GNGSA,A,2,10,12,20,24,32,2.2,2.0,0.9,13C
$GNGSA,A,2,2.2,2.0,0.9,238
$GNGSA,A,2,2.2,2.0,0.926
$GNGSA,A,2,193,194,2.2,2.0,0.921
$GNGSA,A,2,04,2.2,2.0,0.9,33D

1 Like
3

@Vianney
Thanks for sharing.

Could you please add your current NMEA config?
AT!GPSNMEASENTENCE?

Which version are you running?

Issue 1 is the most severe one (Speed is always 0.0)

The other 3 are low prio
After rebooting the module multiple times, I’m now seeing GPDTM

Thanks!

4

@koenvandeputte
I use the same setting as yours.
Here is my setting:
ati9

Manufacturer: Sierra Wireless, Incorporated
Model: EM7565
Revision: SWI9X50C_01.09.04.00 6d3218 jenkins 2019/02/26 20:33:22
ESN: 12803145987, 80300103
IMEI: 357756090004611
IMEI SV: 9
FSN: UF810187020206
+GCAP: +CGSM

OK
at!gpsnmeasentence?

!GPSNMEASENTENCE: 0xC9FDF

OK

5

Some more details on the issue regarding speed:

When only GPS sentences are enabled, speed is fine.
When the sentences for other constellations are enable, speed is always 0.0

Smells like a bug …

6

Ping.
Any update on this from Sierra dev team?

It’s pretty easy to simulate:

1

  • Only enable GPS sentence bits
  • Get a GPS fix
  • Move around (see speed in NMEA strings) --> OK

2

  • Enable GPS + GLONASS/GALILEO sentence bits
  • Get a GNSS fix
  • Move around (see speed in NMEA strings) --> BAD, speed is always 0.0
7

Retested on revision: SWI9X50C_01.11.00.00 5ba42f jenkins 2019/06/28 09:51:52

The main issue is still the same:

  • Speed is 0.0 in all sentences when other GNSS constellations besides GPS are also enabled