Thank you all for your help !! but the readings I get are all zeros.
this is the circuit:
Emitter: I connected 5v in series with a resistor(190 ohm) to the (+) pin, and the (-) to the gnd.
Receiver: I connected 5v directly to the (+) pin, and the (-) to the analog input and to gnd with (1k ohm) resistor.
is that correct ?!