Reviving 3110 support

[Osma Suominen]

Hello world,

I recently acquired a Nokia 3110 together with the original data cable.
I thought it would make a nice SMS gateway. Alas, I soon found out that
recent versions of gnokii (after 0.3.5) don't support 3110.

I decided to see what I could do to get it working again. gnokii-0.3.5
is really not something you want to start building something on.

Now after some intensive hacking I've got 3110 support working to some
degree on a modified gnokii-0.5.0pre4 (I couldn't get a recent CVS
snapshot to compile so I picked that as starting point). That is, the
phone is identified and I can read, save and send normal text SMS
messages. I haven't even dared to try data calls yet, but it shouldn't
be impossible to get those working too given that 0.3.5 works (haven't
tried that myself, though).

I've stumbled on some problems with the internal data formats that
recent versions of gnokii use. I think the current way things are done
makes a lot of sense: SMS handling mostly happens in the middle layer
and the phone-specific assembly of SMS requests (that used to be done
with SMS layouts, if I understood the idea correctly) is done in the
phone-specific parts of code.

However, the 3110 is special because it likes to do some of the encoding
of data itself. For example, it expects phone numbers in plain ASCII
strings, not BCD, and plaintext SMS messages also on plain ASCII
strings, not in packed 7-bit format. So I've had to do some ugly tricks
(usually encoding/decoding back and forth) to get stuff to be in the
right format for the phone. The middle layer, of course, specifically
the gn_sms_raw data structure, uses BCD numbers and 7bit encoding of
plaintext user data.

I have some questions for you Gnokii hackers. Are you interested in
getting 3110 support working again? Do you have a solution for the
abovementioned problem of encodings - for example, there could be a
driver-specific flag saying "don't do 7bit encoding for me, please" - or
should I just work around it in the driver code as I've done now? I
haven't dared to touch anything else than common/phones/nk3110.c in
order not to step on anyone's toes. (well, except a Makefile and
some code to enable the 3110 driver)

I'm sorry I can't show you the code yet, I have it on my laptop which is
currently without a net connection. But I'll continue hacking on it and
publish it in a few days.

Osma Suominen

PS. There's one anomaly - the phone only sends one SMS message, after
which sending fails with the error code 0x65 0x15. Saving etc. still
work. This also happens with gnokii-0.3.5. Power-cycling the phone
helps, but then again only one SMS can be sent. A comment in the old
code said that the error code was for the situation where "the phone
originated SMS was disabled by the network for the particular phone".

Any clues to what this could mean? I'm using the Finnish Sonera network,
if that matters. Maybe there's something suspicious about the message,
and the network denies further messages??

-- 
*** Osma Suominen *** address@hidden *** http://www.iki.fi/ozone/ ***