Alarm

This project is I make an example from Flynn_munroe.

https://www.instructables.com/id/Arduino-Distance-...

It’s idea is from the author, not my own.

This is the picture that how you connect the circuit.

here is my own example

https://create.arduino.cc/editor/MaxHs/399240bb-2a...

This is the code that my work have.

I think when you are sleeping, the alarm will ring when someone comes in, then you may wake up and notice that someone comes in.