Hi there! I have a problem with my siemens Mc75 modem. The thing is that everyting is working on the development board. When i try the same code with the nessesary changes tha modem appears to hang when i enter pin code. Every AT command exept AT+CPIN=8822 works and replies correct data. But CPIN anwers nothing. We have seen on orchiloscope that there is a clock signal to the sim, but it stopes after approx 2 sek of communication with the sim, there is also some communication going on when requesting SIM code. But the modem doesn aswer anything to the uart. I think that you must have AT+Cpin in you code to get connection to the internet, becouse else AT+CREG never comes.
Have anyone experiensed the same problem or have any idea. Everything would be helpful.
/Regards Martin Senior Deverloper Lansen AB