Circuit Lake

Electronic Project and Circuit Collection

AVR Security Keypad Lock

02/09/2012 Category: AVR, Control, Microcontroller, Project, Security System

The Security Keypad Lock Project is a basic access control system based on ATtiny2313. It can be modified to protect just about anything. The “Code Lock” ability will allow the rightful user to deploy the platform to any property that requires simple password-protection.

AVR Basic Keypad Lock System


The “AVR” RISC microcontroller used ensures low costs. Possible applications may include: vehicle protection, electronic safes, powered door locks. The following short treatise will explain how the early version was engineered and how to use the controller to accept valid passwords. With a little external hardware, the featured systems may easily be used to disengage an electric door strike or similar system.

Keypad Lock Flowchart

This console project is intended to be a low-end and low-cost system that will focus mainly on affordability and simplicity rather than connectivity or even ease-of-use. Hence this will be a stand-alone system that will not need a special communications interface. This limits the design phase to four sub-systems: keypad, encoder, controller, and visual/mechanical interface.