MC8090 GPS.

IoT Modules MC/EM Series
1

Dear all,

Recently I’m working on a project that uses a MC8090 wireless module on a Linux platform. As I could notice, this module is really new, and suffer of a serious lack of documentation. The 3G modem works really fine, but when I tried to use GPS, it don’t work properly. Despite the correct flow of NMEA messages, the GPS can’t “see” any satellites. Following, a example of the data flow:

$GPGSV,4,1,16,20,18,24,28,*7C
$GPGSV,4,2,16,19,27,06,02,*71
$GPGSV,4,3,16,07,30,22,08,*75
$GPGSV,4,4,16,32,15,16,10,7D
$GPGGA,0,66
$GPVTG,T,M,N,K,N2C
$GPRMC,V,N53
$GPGSA,A,1,*1E
$GPGSV,4,1,16,20,18,24,28,*7C
$GPGSV,4,2,16,19,27,06,02,*71
$GPGSV,4,3,16,07,30,22,08,*75
$GPGSV,4,4,16,32,15,16,10,*7D

As you can see, both GPGGA and GPRMC strings are empty, with any satellites in view. Here the points that I checked:

  1. AT command used: AT!GPSTRACK=1,100,10,1000,1;
  2. The Antenna and MMCX-SMA cable were tested and are good;
  3. With another GPS, we are able to receive GPS signal and the coordinates are fine;
  4. We ran a test of two hours, in several places(including outdoor), but the MC8090 GPS can’t find the satellites.

So, if there’s someone who already passed by these troubles, please post some idea about I need to do.

Thanks to all.

2

Hi,

What is the firmware version used in MC8090.Can you please try with a higher version. Actual GPS functionality is dependent on the firmware version, and on module configuration.

Please check the response of “AT!GPASSATINFO” command. This command returns the following information for up to twelve satellites in view (including those used in the latest position fix):
satellite vehicle number (SV), elevation (ELEV),azimuth (AZI), and signal to noise ratio (SNR).

The information returned is valid regardless of the current fix mode or whether the PDE or the modem performs the fix calculations.

Thanks.

3

Hi Rex_alex, thank you by the reply.

I sent the AT+GMR for my modem, and this was the reply:

[b]P1_0_0_8AP R1338 CNHKGDKCE01 2011/10/21 09:21:31

OK[/b]

I’ve already checked this version, but there’s no reference about this firmware version on UMTS Supported AT Command Reference.

And now, the AT!GPSSATINFO? response:
[b]
NO SAT INFO

OK[/b]

Att.,

4

Any news on this problem? I’m having the same issue. Any help would be great!

Thanks,
Jeff

5

You should begin by getting P1_0_0_20 or later from your FAE.