Problems of serial data transfer through a HC-05 to an Arduino Uno

Hi,

I have been struggling installing my first configuration using an arduino uno and a HC-05 following a tutorial that switch on and off a Led sending 1,0 from an Android. It looks like everything is doing fine except the data that reach the Arduino.
using the monitor of the Arduino programming compiler, i can see that the 1, and 0, i send from my phone get printed as random characters. this makes the sketche not working well, since the characters are not detecting the right values.
I am runing a 9600 bauds transmission. i can detect that the data are going to the arduino, but I have no idea what makes the data not in a proper value?
the light of the led of the HC-05 is blinking regularly (from what i read) it is not in an AT mode, i dont know if that would modify anything?
does anyone has a solution please? could it be a hardware problem? or a wrong setting?

Thank you