By PranP1
How final project looks like
URL: https://www.instructables.com/id/Contactless-Door-Opener/
This project was designed by high school student who was looking for interesting Arduino project. He read a paper about unsanitary of the door knob and decided to build an Arduino project that automatically opens the door. He used an ultra sonic sensor to determine whether someone is standing in front of the door or not and used servo motor to turn the door knob.
Response: I think this is a nice project because like in this huge pandemic, hygiene is important factor to keep our life safe. This project perfectly fits with that motive.
If I were a builder, I would probably used micro receiver that connects with the phone so that we can open door when we wants. If we use ultra sonic sensor, the door might open randomly if I move in front of the door.