help on pc-phone interface
Hello all, I would do a sim-emulator software that runs on my PC. First thing to do is a an interface to connect my PC with sim slot phone. So I am using this simple interface : I took a CP2102 module, see this page for example http://esaid.free.fr/Cdotnet/USB_serial.htm, then I have put a diode between TXD and RXD, then I have connected RXD to I/O of phone sim slot, DSR of CP2102 module to RESET of phone sim slot and connected the two grounds. __________ | |________ TXD +5V------| | | DP------| CP2102 |___ \/__ RXD ------- I/O phone sim slot DM------| | GND-----| |--------- DSR ------- RESET phone sim slot | | |_________|-------- GND ------- GND phone sim slot I have tested this interface with a phone , I can detect reset from phone then I send this ATR: 3B 16 95 D0 01 7B BD 0D 00 ( this is the ATR I can read form a real sim card with a phoenix reader), but I don't have any response from phone. Any help is appreciated, thanks.
Hi, Excerpts from Gabriele.rago's message of Thu Jun 28 12:38:52 +0200 2012:
Hello all, I would do a sim-emulator software that runs on my PC.
First thing to do is a an interface to connect my PC with sim slot phone.
So I am using this simple interface :
I took a CP2102 module, see this page for example http://esaid.free.fr/Cdotnet/USB_serial.htm,
then I have put a diode between TXD and RXD, then I have connected RXD to I/O of phone sim slot,
DSR of CP2102 module to RESET of phone sim slot and connected the two grounds.
SIM cards come in different classes (different operating voltages). First check if this is matching. One important point is that you are completely ignoring the CLK pin. Thus you baudrate might not match the one set by the phone, and additionally you can also be out of sync with the clock. Some old phone have a fixed standard baudrate, that might help (use an osci to debug). kevin
This is maybe a bit off-topic, but you may find easier implementing this as purely software/firmware thing for simtrace itself rather than building a separate device :) Cheers! Lukas On Thu, Jun 28, 2012 at 1:31 PM, Kevin Redon <kevredon@mail.tsaitgaist.info>wrote:
Hi,
Excerpts from Gabriele.rago's message of Thu Jun 28 12:38:52 +0200 2012:
Hello all, I would do a sim-emulator software that runs on my PC.
First thing to do is a an interface to connect my PC with sim slot phone.
So I am using this simple interface :
I took a CP2102 module, see this page for example http://esaid.free.fr/Cdotnet/USB_serial.htm,
then I have put a diode between TXD and RXD, then I have connected RXD to I/O of phone sim slot,
DSR of CP2102 module to RESET of phone sim slot and connected the two grounds.
SIM cards come in different classes (different operating voltages). First check if this is matching. One important point is that you are completely ignoring the CLK pin. Thus you baudrate might not match the one set by the phone, and additionally you can also be out of sync with the clock. Some old phone have a fixed standard baudrate, that might help (use an osci to debug).
kevin
Hi,
then I have put a diode between TXD and RXD, then I have connected RXD to I/O of phone sim slot,
I'm not sure a diode would help here at all ... Usual solution is to have an open collector output with a pullup. Then you have all the issue where a phone could request change of speed via the special PPS procedure (IIRC) and I'm not sure you'd be able todetect and follow it. Adapting the fw of a simtrace board seems like a better solution. Cheers, Sylvain
participants (4)
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Gabriele.rago -
Kevin Redon -
Lukas Kuzmiak -
Sylvain Munaut