Ericsson F5521GW 2XGNJ Dell DW5550 - Does not support GPS / NMEA

Hi,

I noticed that modems:

• Ericsson F5521GW 2XGNJ (Dell DW5550)
• Ericsson F5321 VNJRG (Dell DW5560)

...does not support GPS.

# mmcli -m 1 --location-enable-gps-raw --location-enable-gps-nmea
error: couldn't setup location gathering: 'GDBus.Error:org.freedesktop.ModemManager1.Error.Core.Unsupported: Cannot enable unsupported location sources: 'gps-raw, gps-nmea''

Here's how to get started:

# picocom /dev/ttyACM2
picocom v3.1

port is        : /dev/ttyACM2
flowcontrol    : none
baudrate is    : 9600
parity is      : none
databits are   : 8
stopbits are   : 1
escape is      : C-a
local echo is  : no
noinit is      : no
noreset is     : no
hangup is      : no
nolock is      : no
send_cmd is    : sz -vv
receive_cmd is : rz -vv -E
imap is        : 
omap is        : 
emap is        : crcrlf,delbs,
logfile is     : none
initstring     : none
exit_after is  : not set
exit is        : no

Type [C-a] [C-h] to see available commands
Terminal ready

*EMRDY: 1
ati
DW5560

OK
AT*E2GPSCTL?
*E2GPSCTL: 0,1,0

OK
AT*E2GPSCTL=1,1,0
OK
AT*E2GPSNPD
OK
$GPGSV,1,1,00,,,,,,,,,,,,,,,,*79
$GPGLL,,,,,235951.000,V,N*73
$GPGGA,,,,,,0,0,,,M,,,,*1B
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGST,235951.000,,,,0,,,*70
$GPRMC,235951.000,V,,,,,,,,,,N*44
$GPGSV,1,1,00,,,,,,,,,,,,,,,,*79
$GPGLL,,,,,235952.000,V,N*70
$GPGGA,,,,,,0,0,,,M,,,,*1B
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGST,235952.000,,,,0,,,*73
$GPRMC,235952.000,V,,,,,,,,,,N*47

Terminating...
Skipping tty reset...
Thanks for using picocom

Result:

# cat /dev/ttyACM2
$GPGSV,1,1,00,,,,,,,,,,,,,,,,*79
$GPGLL,,,,,235953.000,V,N*71
$GPGGA,,,,,,0,0,,,M,,,,*1B
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGST,235953.000,,,,0,,,*72
$GPRMC,235953.000,V,,,,,,,,,,N*46
$GPGSV,1,1,00,,,,,,,,,,,,,,,,*79
$GPGLL,,,,,235954.000,V,N*76
$GPRMC,131430.000,A,XXXX.XXXXXX,N,XXXX.XXXXXX,E,0.000,0.0,160121,,,A*6C
$GPGLL,XXXX.XXXXXX,N,XXXX.XXXXXX,E,131431.000,A,A*5F
^C

I noticed a strange thing, if I send AT commands using other software than PICOCOM I have to hold the session.

DEVICE="/dev/ttyACM2"

while true; do
  if [ -c "$DEVICE" ]; then
    sleep 60
    
    if [ -c "$DEVICE" ]; then
      ( chat -t 1 -V -s '' 'AT*E2GPSCTL=1,1,0' 'OK' > $DEVICE < $DEVICE ) 2&>1
      sleep 1
    fi
    
    while true; do
      if [ -c "$DEVICE" ]; then
        ( chat -t 60 -V -s '' 'AT*E2GPSNPD' 'abcdefgh' '' > $DEVICE < $DEVICE ) 2&>1
        sleep 1
        
      else
        if [ -f "$DEVICE" ]; then
          /bin/rm $DEVICE
        fi
        break
      fi
      
    done
  else
    sleep 1
  fi
done

Please add GPS support for these two devices, NMEA works great on them.