mayfair_69:
I connect 5v to the Aref pin ... Because my sensors need a 5v supply and I thought that we have to power the sensor through it therefore
AREF does not provide power to the sensors.
Either leave AREF unconnected or connect a 0.1 uF capacitor from AREF to GND. Until you have an understanding of the purpose of AREF and how to use it correctly do not connect anything else to it.
Edit: quote tag fixed.