Here... This should work. But instead of pins 1,6,5 on the phone side should be 2,3,4.
And additionaly:
put one 15kΩ resistor between pins of the phone 2 and 5
put one 15kΩ resistor between pins of the phone 2 and 7
I've tested this solution on c72 and ti worked with siemens mobile phone manager.
Hi
Thanks for answer! I made in mean while mine search, Russian forums, made a cable, tested and it is OK with Siemens C72 and both software, GSM control and simoco. I send scheme if somebody want to play.
Mine next step is to monitor communication PC-GSM to "see" what must be done for a PIC to control GSM to be able to establish voice channel, and then simple dtmf communication, and then ...
You mean, you wanna make conversations over PC? I have been able to make my phone dial a number using its data modem but that's all.
Have you looked at the full AT command set for Siemens phones? It is the basis of it all.
I have found this list a long time ago on some Russian site. This one is particulary for s45 but the majority of codes should work with all other Siemenses.
I used rs232 port monitor and I saw all communication PC- GSM for setup and then dialing. I found some unknown AT commands ?! So I will to the end of this week analyze it and try to make same connection but pic - gsm. If you are interested I will put here mine result.
Yes for PICs. Goal of the project is a simple and chip communication trough gsm voice channel (FSK- V23 or dtmf) and/or just control of voice communication.