1.4 Methodology

          A number of technologies are available to make such kinds of systems like PIR sensors, Radar sensors, Laser sensors, Infrared sensors, etc. In this raspberry pi based project, we have tried to replicate the same system by using a PIR sensor.  It uses a motion-detecting sensor (PIR sensor) to open or close the door which detects the infrared energy omitted from human's body.

          When someone comes in front of the door, the infrared energy detected by the sensor changes and it triggers the sensor to open the door whenever someone approaches the door. The signal is further sent to raspberry pi microcontroller that controls the door.