Hello Mehdi:
Those configurations are correct. I checked your schematics and the connections seem to be correct, although I have never used that RS-232 voltage transceiver. Please check with the datasheet, unless that connection has worked before, is that so?
Your code seems ok to me, so another test would be to check your pin outputs with an oscilloscope.
Have you been able to run a debug session, or just flash the MCU with the Flash programmer?
/Jorge Gonzalez