Problems to get valid location data with Sierra Wireless MC7455
u.oelmann at pengutronix.de
Fri Sep 21 10:02:24 UTC 2018
Aleksander Morgado <aleksander at aleksander.es> writes:
>> While just pasting ModemManager's log for the first time I stumbled
>> across the second warning ("Could not grab port (tty/ttyUSB1): 'Cannot
>> add port 'tty/ttyUSB1', unhandled serial type'"), and presumably this is
>> the reason for not getting any location data as /dev/ttyUSB1 seems to be
>> the source for GNSS information, right? So what am I doing wrong here?
> That is not the issue, no. ttyUSB1 may be unhandled, because you're
> really receiving all location information via QMI LOC service. If you
> run MM in debug mode (with --debug) then you should see all QMI LOC
> messages being reported every 1s with the NMEA traces reported by the
> modem. You can see those NMEA traces in mmcli output (e.g. GPGGA...)
> but the module isn't returning any location yet.
in fact I repeatedly see many many lines a'la
[/dev/cdc-wdm0] received message...
[/dev/cdc-wdm0] received generic indication (translated)...
<<<<<< type = "NMEA String" (0x01)
<<<<<< length = 26
<<<<<< value = 24:47:50:47:47:41:2C:2C:2C:2C:2C:2C:30:2C:2C:2C:2C:2C:2C:2C:2C:2A:36:36:0D:0A
<<<<<< translated = $GPGGA,,,,,,0,,,,,,,,*66
<debug> [1517443403.601456] [NMEA] $GPGGA,,,,,,0,,,,,,,,*66
which is found in the NMEA traces of the mmcli output as well - so it
looks like the data steadily sent by the MC7455 contain always the same
message of invalid location data and at least the software side can be
regarded as being okay.
>> Then there are additional QMI related warnings ending with "No valid
>> firmware images listed. Assuming firmware unsupported." - could it be
>> that they are somehow related? Do I have to flash a more current
> Nah, don't think those are related.
>> If this looks familiar to somebody I would be very glad to get a hint
>> where to look deeper.
> I assume that given that you don't have network connection, A-GPS may
> not work at all, so you're really running with standalone GPS. [...]
I have the board in our lab where it is connected to the internet via
LAN, so I manually downloaded the data for assisted GPS and sent it up
to the modem
root at MP:~ wget http://xtrapath1.izatcloud.net/xtra3grc.bin
--2018-09-21 11:33:49-- http://xtrapath1.izatcloud.net/xtra3grc.bin
Resolving xtrapath1.izatcloud.net (xtrapath1.izatcloud.net)... 126.96.36.199, 188.8.131.52, 184.108.40.206, ...
Connecting to xtrapath1.izatcloud.net (xtrapath1.izatcloud.net)|220.127.116.11|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 29150 (28K) [application/octet-stream]
Saving to: ‘xtra3grc.bin.6’
xtra3grc.bin.6 100%[==============================>] 28.47K --.-KB/s in 0s
2018-09-21 11:33:49 (324 MB/s) - ‘xtra3grc.bin.6’ saved [29150/29150]
root at MP:~ mmcli -m 0 --location-inject-assistance-data=xtra3grc.bin
successfully injected assistance data
Waiting for 15 minutes I still get no valid location
root at MP:~ mmcli -m 0 --location-get
3GPP location | Not available
GPS NMEA traces | $GPGGA,,,,,,0,,,,,,,,*66
Raw GPS | Not available
CDMA BS | Not available
> [...] Do you have the GPS specific antenna connected to the module? Do
> you have good satellite coverage?
The GPS specific antenna is connected to the module and hopefully the
satellite coverage is sufficient (my mobile phone tells me that it sees
10/27 satellites if it is held next to the GPS antenna). So I assume
that perhaps there is some technical problem with respect to the antenna
which should be excluded before further suspecting the software setup.
Have my big thanks for helping! :-D
(At least I hopefully can give a little bit back as I stumbled across a
small thing in the code that I am going to send a patch for right now).
Pengutronix e.K. | Ulrich Ölmann |
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