I try to figure out how to make this project.
Based on this video: Open, Sesame - entry phone hack - YouTube
However, I don't care about the voices I just need that the door opens.
I will replace directly my interphone by the arduino.
My idea was If arduino listens at a digital input 3 times in a row over a period of time of 6 seconds, then arduino send an Output signal to open the entrance door.
I know how to make this with just 1 digital INPUT but how to introduce my conditions just above explained?