How can I help to add ublox Sara-270 support on ublox branch?

[Schroer, Jens Peter]

Hi,
sorry for the long response time. Did not have the time to dig into this 
more up till now.
Happy new year.

First, I tried the ublox branch. It does recognise the modem and loads 
the plugin, however when
doing a mmcli -m 0 --simple-connect it fails while creating the bearer.
Up on closer investigation the step CREATE_BEARER_STEP_CHECK_MODE fails.
Reason is that only Toby supports the used UBMCONF command.
For SARA, if the modem is switched into CDC-ECM mode, it can only act as 
bridge.
Also the commands UIPADDR are Toby specific, as for the SARA the network 
config happens by
first configuring a PDP context, say context one, and then running 
UCEDATA=1,0 (where 1 is the id of the PDP context)
to establish the data connection. DHCP needs to be handled by host OS in 
this case.

 From my point of view the logic for SARA should be
1. Check USB profile (as done now)
2. If modem is SARA assume bridge mode
3. Configure the PDP context (say 1)
4. Run UCEDATA=1,0 to establish data connection.

I studied the code, but I am not sure how you would like to distinguish 
the different ublox models?
create_bearer_step is the first place where I would need it and then 
after that I would assume also on the connect method of the
MMBroadbandBearerUblox?

What do you suggest?

Kind regards,
Jens

On 2016-09-23 21:42, Aleksander Morgado wrote:
>> We are running it in an USB ECM configuration, but unfortunately the 
>> Sara
>> firmware does not, unlike Toby, contain
>> and auto-connect mode. Everytime the system is booted up, I still need 
>> to
>> execute a +UCEDATA=1,0 command to bring
>> it online.
>> I saw that there is a ublox branch in modemmanager. I would be more 
>> than
>> happy to try to add above command to the branch.
>> 
>> I had a look at the online documentation for modemmanager that I could 
>> find,
>> but I think I am still a bit unclear where
>> to start ideally.
>> I assume the command should be executed if the ublox pluging detects 
>> the
>> modem to be in the ECM USB profile and command is a
>> connect command (I am thinking mmcli -m 0 --simple-connect).
>> 
>> Am I correct in my thinking?
>> If so I can try to find my way from there.
> 
> You'll need to modify the "MMBroadbandBearerUblox" so that the
> connection logic does +UCEDATA as connection command. Did you try the
> ublox branch anyway? Don't Sara and Toby use similar connection
> procedures? The ublox plugin does support Toby in ECM mode.