EHS8 A-GPS configuration | Telit Cinterion IoT Developer Community
November 25, 2015 - 3:16pm, 5846 views
Hi,
I have configured the EHS8 GPS like this:
at^sgpsc?
^SGPSC: "Engine","1"
^SGPSC: "Nmea/Output","on"
^SGPSC: "Nmea/Freq","1"
^SGPSC: "Nmea/Data","GGA,GSA,GSV,RMC,VTG"
^SGPSC: "Nmea/Interface","asc0"
^SGPSC: "Power/Antenna","auto"
^SGPSC: "Mode/Antenna","0"
^SGPSC: "Assist/Address","<NO ADDRESS TYPE>","<NO ADDRESS>","<NO PORT>"
^SGPSC: "Assist/Data"
^SGPSC: "Assist/Connection"
I also configured AT+CGDCONT=1,"IP","internet", AT^SGPSDNS=1,1, AT+CGACT=1,1 and AT^SGPSC="Assist/Connection",1,0.
AT^SGPSDNS? gives: ^SGPSDNS: 1, "195.197.54.100", "195.74.0.47".
If I try to start the GPS in mode 1, I will get an error; only mode 3 is possible.
at^sgpsc="Engine","1"
+CME ERROR: operation not allowed
at^sgpsc="Engine","3"
^SGPSC: "Engine","1"
With mode 3, I will get NMEA Data out; 6 / 9 satellites on my window etc..
I am missing something: how to configure the A-GPS server address?
Antero Markkula
Communication and Mechatronics
Enkom Active Oy – www.enkom-active.fi
Upseerinkatu 3 A, 02600 Espoo, Finland
Mobile: +358 400 411368
Office: +358 10 204 0000
Fax: +358 10 204 0010
E-mail: antero.markkula@enkom-active.fi
Hello,
You can configure the address with AT^SGPSC="Assist/Address" command. Please also remember to specify the PDP context identifier with AT^SGPSC="Assist/Connection" command.
Regards,
Bartłomiej
Hi,
I configured the AT^SGPSC="Assist/Address","FQDN","supl.google.com","7276" and
specified the PDP context AT^SGPSC="Assist/Connection",1,0.
Whan I start the GPS I will get:
at^sgpsc?
^SGPSC: "Engine","1"
^SGPSC: "Nmea/Output","on"
^SGPSC: "Nmea/Freq","1"
^SGPSC: "Nmea/Data","GGA,GSA,GSV,RMC,VTG"
^SGPSC: "Nmea/Interface","asc0"
^SGPSC: "Power/Antenna","auto"
^SGPSC: "Mode/Antenna","0"
^SGPSC: "Assist/Address","FQDN","supl.google.com","7276"
^SGPSC: "Assist/Data"
^SGPSC: "Assist/Connection"
and the NMEA looks like:
$GPGGA,063638.27,6012.9953,N,02449.1189,E,1,07,1.25,66.19,M,,M,,*4F
$GPGSA,A,3,7,8,18,21,26,27,30,,,,,,2.00,1.25,1.75*02
$GPGSV,4,1,14,07,16,323,41,08,21,295,40,10,45,164,,13,20,039,23*77
$GPGSV,4,2,14,15,24,076,,16,45,224,19,18,53,140,28,20,29,055,*7A
$GPGSV,4,3,14,21,61,094,29,22,28,184,26,26,24,199,25,27,52,283,45*74
$GPGSV,4,4,14,29,01,122,29,30,11,353,33,,,,,,,,*7A
$GPRMC,063638.27,A,6012.9953,N,02449.1189,E,0.10,16.11,301115,,,A*6B
$GPVTG,16.11,T,,M,0.10,N,0.19,K,A*03
Regards,
Antero
Antero Markkula
Communication and Mechatronics
Enkom Active Oy – www.enkom-active.fi
Upseerinkatu 3 A, 02600 Espoo, Finland
Mobile: +358 400 411368
Office: +358 10 204 0000
Fax: +358 10 204 0010
E-mail: antero.markkula@enkom-active.fi
Hello,
To test the assisted GPS you can measure the time from cold start to 3D fix.
One more thing I've missed in your first post - you should use engine 2 (please see AT commands specification for more details). The reply is not the engine value but the engine state (1 - engine is on).
Here's the example:
1. Setup the module with AT command
at^scfg="Gpio/mode/GPSANT","std"
//Restart module
at^sgpsc="Power/Antenna","on"
at^sgpsc="Mode/Antenna","1" [active antenna]
//restart module
//register to network and setup pdp context [to use engine 2]
at+cgdcont=1,”IP”,”APN_ADDR” // set your location APN
at^sgpsdns=1,1
at+cgact=1,1
at^sgpsc="Assist/Address","FQDN","SUPL.NOKIA.COM","7275" // or google server
at^sgpsc=”Assist/Connection”,1,0
at^sgpsc=engine,2 // start gps
2. Record the time after the 3D fix of GPS
3. Clear the A-GPS data saved in the module. // this step is important. It is to clear the data saved in the module.
At^sgpsc= "Assist/Data",1,0
At^sgpsc= "Assist/Data",2,0
4. Restart the module
5. Repeat above step and record the time after 3D fix of GPS
Regards,
Bartłomiej
Thanks Bartłomiej!
Everything works, even on my window inside of our office. I enclose test results. There is a NW offset about 25m with EHS8 and 8m with PH8-P. The offser is always there. Do you have any idea why?
Regards,
Antero
EHS8testresults.pdf
Antero Markkula
Communication and Mechatronics
Enkom Active Oy – www.enkom-active.fi
Upseerinkatu 3 A, 02600 Espoo, Finland
Mobile: +358 400 411368
Office: +358 10 204 0000
Fax: +358 10 204 0010
E-mail: antero.markkula@enkom-active.fi
Hello Antero,
Thanks for the results.
PH8 has GNSS receiver on board and EHS8 GPS only. So this might be the explanation for better accuracy of PH8.
The offset in general is also probably caused by the system inaccuracy. But why you have always this offset in NW direction it's hard to explain. Have you tried to measure in different locations or in your office room only? Maybe this has something to do with your window location and that the antenna does not see the whole sky but mainly the NW part.
Regards,
Bartłomiej