Hello SIMtrace community,
I mentioned earlier on this list, and also in last week's OsmoDevCall,
that I play with some old phones that *may* be putting out 5V toward
the SIM, which SIMtrace2 hw does not tolerate - 5V exceeds the absolute
maximum rating spec of SAM3S chip.
As the first step in the investigation, I cobbled together a simple
PCB design for a purely passive adapter that connects a SIM socket to
FPC cables from current Sysmocom SIMtrace kits, plus 2.54 mm headers
on both sides of the SIM socket providing convenient probing access to
all signals. This trivial design can be found in my fc-small-hw Hg
repository:
https://www.freecalypso.org/hg/fc-small-hw/
Look in the sim-fpc-pasv directory inside the Hg repo. I haven't sent
this little PCB out to fab yet, but I plan on doing so when my budget
allows it, hopefully no later than a week from now. When I get this
adapter board fabbed and assembled, I will test it with my current
collection of old phones (Ericsson I888, Nokia 5190 and 6190) and see
if any of these phones put out 5V toward the SIM.
Nokia 5190 and 6190 are powered by 3-cell NiMH batteries, but they
still might put out 5V toward the SIM if they include a charge pump or
some other boost converter. At least in TI chipset history, prior to
our well-known Calypso+Iota chipset, their previous ABB chip Nausica
(used in the legendary TSM30, apparently) could put out either 3V or
5V toward the SIM, selection under fw control, while powered by a
3-cell NiMH or 1-cell Li-ion battery, doing some kind of boost
conversion for 5V. (I never found a datasheet for that ancient ABB,
so I don't know the full details.) It will be interesting to know
what Nokia 5190 and 6190 do in this regard. It will also be
interesting to see what Ericsson I888 puts out: it is an older,
higher-voltage beast, powered by a 4-cell NiMH battery, and if the
designers felt like operating the SIM in "5V" or Class A mode, they
could have used raw battery voltage without conversion, as the spec is
4.5 V minimum IIRC.
During last week's OsmoDevCall Kevin said that he had some SIMtrace1
boards with ARM7S, which the datasheet says is 5V-tolerant, and I
recall him saying that he could send me one. To Kevin: I greatly
appreciate your offer, and I may indeed take you up on it in another
few weeks - but let me build my sim-fpc-pasv adapter first, and see
what voltages are actually put out by phones in my collection.
Now the really interesting phone would be Nokia 2190 - supposedly one
of the very first PCS1900 band GSM phones sold in USA, from around
1995. That one is powered by a 5-cell NiMH battery and thus seems
very likely to put out 5V toward the SIM, possibly always, without
ever switching down to 3V. I don't have one to test, aside from a
sealed box which I am reluctant to cut open (told it may be worth
a fortune some day, the usual story), but another person on Reddit
says that these phones are very finicky in terms of which SIMs they
accept. I sent him a few of my FCSIM1 cards, equivalent to
sysmoSIM-GR2, a pure GSM 11.11 SIM without any UICC at all, very
old-fashioned, and my contact tells me that Nokia 2190 rejects these
SIMs too! It was my desire to use SIMtrace to see what's happening
with that finicky 2190 that prompted my investigation into 5V
tolerance - and when I get my sim-fpc-pasv adapter built, I will get
back in touch with my Nokia 2190 contact person from Reddit and see
how he would like to proceed.
M~
Hello various Osmocom mailing lists,
as previously announced (https://osmocom.org/news/191):
* The binary packages are being built on Osmocom's own OBS server now.
* We will stop pushing packages to the openSUSE OBS server at the end of
October (in one week).
If you are using Osmocom binary packages, please make sure that you have
configured the new repository URLs.
See the wiki for details:
https://osmocom.org/projects/cellular-infrastructure/wiki/Binary_Packages
Regards,
Harald
--
- Harald Welte <laforge(a)osmocom.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Dear Osmocom community,
after a rather extended 2022 summer break, we're happy to announce the
next incarnation of OsmoDevCall. Based on the recent polls, the timing
has shifted to *every 3rd wednesday of the month*!
when:
October 19, 2022 at 20:00 CEST
where:
https://meeting5.franken.de/b/har-xbc-bsx-wvs
In this edition, I will be presenting a SIMtrace2 tutorial, showing SIM
card protocol tracing, decoding with the new pySim-trace as well as the
card emulation firmware.
This meeting will have the following schedule:
20:00 meet + greet
20:10 presentation as outlined above
21:00 unstructured supplementary social event [*]
Attendance is free of charge and open to anyone with an interest
in Osmocom or open source cellular technologies.
More information about OsmoDevCall, including the schedule
for further upcoming events can be found at
https://osmocom.org/projects/osmo-dev-con/wiki/OsmoDevCall
Looking forward to meeting you soon!
Best regards,
Harald
[*] this is how we started to call the "unstructured" part of osmocom
developer conferences in the past, basically where anyone can talk about
anything, no formal schedule or structure.
--
- Harald Welte <laforge(a)osmocom.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Dear Osmocom community,
your input is required in order to tune the re-launch of the OsmoDevCall
talk series. One of the complaints before the suspension in Summer this year
was that the "Friday night 8pm CEST" timeslot was not exactly ideal for several
people.
Finding a common denominator might be difficult, given that Osmocom is a dayjob
for some, a hobby for most, and we're of course not all in the same time zone
or even continent.
So let's try to run a couple of polls to figure out:
* What is the best day of the week for OsmoDevCall?
https://bitpoll.de/poll/CEQnaQKEvO/
* What is the best time of day for OsmoDevCall?
https://bitpoll.de/poll/59dgmzOocT/
* What is the best frequency of OsmoDevCall
https://bitpoll.de/poll/8jyuRJB6Hb/
The polls are open until October 21st, 2021. I would appreciate a high turn-out
so we have a good representation across our community to make an educated decision
about the schedule of futur events.
Can't wait to re-start OsmoDevCall!
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hello SIMtrace community,
I just bought a SIMtrace v2 hw kit, and I am looking to use it for the
purpose of troubleshooting ancient phones. I've been working with
Calypso phones mostly, but now I am traveling farther back in time in
the history of GSM, playing with phones from 1990s. I bring these
phones up on my own GSM network run with a sysmoBTS plus Osmocom CNI
sw stack, and I use programmable SIMs of which I bought a semi-custom
batch from China a year and a half ago, semi-custom batch meaning my
own artwork on the plastic and my choice of 2FF-only cut, but the
actual module is unmodified off-the-shelf, the only thing I could get
as a low-dollar customer. These SIMs (I named my version FCSIM1)
appear to be identical to the model known in the Osmocom community as
GrcardSIM2, once sold as sysmoSIM-GR2.
Here is the issue: my SIMs work just fine in Ericsson I888, Nokia 5190
and Nokia 6190 - all 1990s phones - bringing these ancient phone onto
my Osmocom-based GSM network quite happily. But I am interacting with
another member of the vintage phone community (r/vintagemobilephones
on Reddit) who has a few working Nokia 2190s - a phone model from 1995,
one of the first PCS1900 band phones ever - and he tells me that this
super-ancient model is very finicky in terms of which SIMs it accepts.
There are several T-Mobile MVNOs who issue SIMs that still have the
classic GSM 11.11 SIM application present, and they work fine in most
ancient phones, including Nokia 5190 and 6190, but they don't work in
2190 - my contact tells me that he found only one MVNO (Lycamobile)
whose SIMs do work in the 2190. Intrigued, I sent him a few of my
FCSIM1 cards, he tested one in a 2190, and he tells me the ancient
phone rejects this SIM too. :-(
At this point the rational course of action ought to be to trace the
SIM-ME communication between the finicky phone and one of each kind of
SIM: the kind it accepts, and the kind it doesn't accept, and see what
it barfs on. But I just realized a problem: there is a very high
likelihood that the ancient phone feeds 5V to the SIM (Nokia 2190 is
powered by a 5-cell NiMH battery, so it has plenty of voltage headroom
inside to put out 5V), and my reading of Atmel's datasheet for the
SAM3S chip on the SIMtrace board tells me that 5V will fry it: the
electrical specifications chapter of the datasheet lists 4.0 V as the
Absolute Maximum Rating for all pins, including those GPIO pins that
are wired to the phone connection on the SIMtrace board.
Just checking to see if my understanding is correct: is SIMtrace v2
indeed absolutely NOT tolerant of phones that put out 5V toward the
SIM? Not tolerant to the point that it would not simply not work, but
would *fry* the SAM3S chip?
If the board part of SIMtrace v2 kit is of no use with ancient phones
that put out 5V, I reason that I should still be able to make use of
FPC cables: I just need a little adapter PCB that hosts a SIM socket
and a connector for the FPC to go into, with accessible points for
probing with an o'scope or a logic analyzer - it just needs to be a
purely passive, connections only PCB, without any ICs that would be
fried by high voltages. Would anyone happen to know if I can still
buy such an adapter PCB anywhere (I read that such were used in the
beginning of the project before the first custom SIMtrace board), or
will I need to spin out that adapter PCB myself?
TIA,
Mychaela
