avr - Siemens MC35 + ATcommand -

i 2 things.

1. recognize when calling - in terminal appear ring , answer have send command ata. how can recognize when doing else. should use new thread , read port until send ring? there beter solution?

2. what symbol of end of response? i'm reading char using for(), not know number of signs. example below doesn't work properly

     while(readcharuart()!=10) {};    while(readcharuart()!=13)   {         getchar() = ..     } 

you on right track.

for ring yes, correct way have 1 thread read modem responses until unsolicited result code ring. if time time want run @ commands (say ata), should let thread well, e.g. have 1 thread takes care of both issuing @ commands , monitor ur codes.

regarding formatting of responses modem, described in chapter 5.7.1 responses in itu v.250 standard. short summary (reading spec highly recommended!):

<header>ring<trailer> 

where header , trailer both "\r\n" (unless modem configured strangely).