README

Simple Combination Lock

Simple combination lock utilizing an ATMega32, simple speaker, 16 input keypad and LCD screen. This combination lock supports four states: locked, unlocked, change password and manager password, which is used for bypassing lockout).

In locked state, users use the keypad to input a 6 digit numerical passcode at which they would the "#" key on the keypad to submit their input. Upon receiving the input, the ATMega32 will choose to either change to unlocked state if the inputted passcode is correct or stay in unlocked state if the passcode is incorrect. 

After three incorrect guesses in a row, the lock will enter a timeout stage which will not allow users to submit any inputs for a minute. This can be bypassed by entering the manager state by clicking the "#" button.

In manager password state, users can input another password to bypass the timer. By default, the manager password is "123456" and if entered correctly, the lockout timer will be reset granting users all three guesses again. Otherwise, the timer continues.

In unlocked state, users can either choose to enter the change password state by pressing the "#" input or entering locked state by pressing the "*" input. 

In change password state, users can enter a new 6 digit password in, and save the password by pressing the "#" key. This saves the newly inputted password as the combination lock's passcode and in locked state, this new passcode and only this new passcode will change the lock's state from locked state to unlocked state.