Where do the AT codes live in the source tree?

[Dan Williams]

On Thu, 2019-07-04 at 15:30 -0700, Christopher McKenzie wrote:
> Hi All,
> 
> One of my EEs was doing some direct AT commands to try to increase
> our 
> understanding of a likely issue with some Quectel modems having
> pretty 
> unreliable GPS.
> 
> I come at this from the assumption that everything we're going to 
> discover is already in the codebase somewhere and we just need to
> find 
> out how to invoke it correctly, but I was unable to find any place
> where 
> the GPS or NMEA commands were being sent either in libqmi, libmbim,
> or 
> modemmanager ... I assumed they'd be in libqmi. Is there some library
> I 
> forgot to check or did I just grep the wrong strings?
> 
> If someone knows the general place to start looking, that would be 
> wonderful (project/path). Thanks and have a great day

libqmi deals only with the QMI protocol, not with AT. So if you want to
see how the AT side happens, you want to look in the ModemManager
sources:

https://gitlab.freedesktop.org/mobile-broadband/ModemManager

but the ModemManager Quectel plugin doesn't support AT-only location,
just MBIM and QMI-based location which doesn't use AT commands. So
you'd probably have to look elsewhere if you really do want to use AT
commands with the Quectel modem.

What kinds of things were you trying to do?

Dan