I realize that using
echo at > /dev/ttyS0
I receive the answer in other shell with
cat < /dev/ttyS0
in the same way I send a sms and read. sending the apropiates at+commands
So it is easy comunication with linux
I wonder if it is possible use the gcc arm compiler and download the programs using similar at comands
I see that developer in windows is gcc and the includes are something like wm_types.h
so it is posible use the same include in gcc - cross compiler linux host.
Than you in advance for your opinion.