[Gta04-owner] Detect Call Hangup / Option Datasheet

[Thomas Gstädtner]

Hi guys,

I'm unfortunately not yet an GTA04 owner, but I got to play with one the
last few days and I have some questions/problems.

1) The Option modem seems to start up with AT+CFUN=1, while usually
defined behavior is AT+CFUN=4. No big deal, but as I see it, phone
applications usually expect it to start in standby and this makes sense,
only Data-only devices in USB factor sometimes start off in =1.
Can this be changed, or why is this set in the Option device?

2) With the help of the ofono guys I added basic support for voicecalls
of the GTA04 to ofono (not upstream). Unfortunately this is quite
difficult to begin with, making and taking calls works just fine, but it
does seem impossible to detect if the call partner hung up, either
before accepting (=sending to voicemail and such) or after (hanging up a
successful call).
The reason is, that the AT interface never reports this (which it
should), so software can never known when someone hung up on you.
You could in theory work around that by polling with AT+CLCC or
something like that, but that's really uncomfortable and messy and the
ofono guys really aren't happy with such an approach (which I fully
understand).
Is there some other way I missed? Can you provide a newer firmware from
Option that fixes this?

3) So far I only found the GTA04 handbook, no documentation to the
Option modem itself.
The AT-Commands in the GTA04 handbook are not really helpful, first of
all, there are very few of them, secondly many of them just don't work
(i.e. a lot of the option specific stuff).
There's really a lot of stuff that would be really needed or could be
very useful - and some documentation for other Option calls would be
great, too. Is there any documentation available? Can you get one from
Option to release?

Thanks in advance,

thomasg