How to detect a metallic object in the range of 1.5 to 0 meter

Hi everyone,

I have a project. Among the different types of objects, i want to detect special metallic object. I can move the sensor for the related area but i can't pass go through other types of objects. Let's thinking easy;

this is my sensor: :roll_eyes:
these are other objects: :drooling_face: :wink: :roll_eyes:
this is my metallic object: :money_mouth_face:

:roll_eyes: ----------> :drooling_face: :wink: :money_mouth_face: :roll_eyes:

How can i detect :money_mouth_face: (0m<Its distance from the sensor<1.5meter) among other objects.

I will be grateful if you can help me or simply give your idea about this.

Thank you so much.

You should have asked that question in the "Sensors" section.

There are several possibilities, depending on the definition of "metal". Which kind of metals are allowed? If it's iron or steel you may use a magnetometer to detect the object.
If the metal conducts current you may use an induction loop to detect.