3.5 Access Control System

Share for us


The access control system is the system that is used to control the entrance channel, which is developed on the basis of the traditional door lock. The traditional mechanical door lock is only a simple mechanical device, and no matter how reasonable the structural design is, how strong the material is, people can always open it through various means. The key to the entrance and exit (like an office building, a hotel room) is cumbersome. If the key is missed or replaced, the lock is to be replaced with the key. In order to solve these problems, the electronic magnetic card lock and the electronic coded lock are present, which has raised the management level of the access channel to a certain extent, and then the channel management enters into the electronic age.

Components Required

Fritzing Circuit

In this example, Power Supply Module is used to power the breadboard. We get the GND of Mega 2560 Board connected to the cathode rail of the breadboard, GND of ULN2003 to the cathode rail of the breadboard, VCC to 5V OUTPUT of Power Supply and the Stepper Motor to OUT1-OUT5 of ULN.

Schematic Diagram

Example Explanation

The workflow of the access control system is shown in the flow chart. 

When there is no authorized ID identified (the variable “Approved” equals to 0), the device will perform functions of ID identification and password identification. 

If the authorized ID is identified (“Approved” equals to 1), the door will open. After that, the door will be closed a few seconds later and the identified status will be reset (“Approved” equals to 0).

In addition to the core access control function, the project also uses LCD and active buzzer to complete the work of the user interaction system of the access control system.  

Phenomenon Picture