a lock code based switch using atiny2313

Hello members I want to do an password based switch using atiny2313
where i start ?
where can i sotre the password (whic can change by the user not programmer)
please help me thanks

I cant tell you to much about atiny Ive not used one before but you could apply latteral thinking to how you might develop this on pic mico First of all you would need some type of display output

This might be leds, lcd, 7 or 14 segment display
Next you would need to decide on number of password characters This would include a descision with regards alpha characters,numerical only or both

With reference to the above point you need to determine total byte size so as to be able to store and read this characters back

You might also conciders some type of internal encription, decription method for your password

In the same instance you might possibly also concider random address storage as you would with file io on a pc

Now we move to storage and where to store You have two options either you use internal eeprom or opt for external eeprom in which case you need to research memory devices and communication protocols

You need also to consider How you initially write password to your storage eeprom and detect if this has been changed with possible date stored at the same time

User interactions

How would you interface with users example button sequences with obvious display indication

A time out or retry for password entries
Tamper proofing Ask "what if this happens? " Taking each case and formulating your answers to provide solutions in each case

Checking password

How would you read this back in and into what Error checking, timeouts, retry attempts or match no match

Finally hardwire security again asking "What if ", Dealing with each case

After completion all tests rendering true then obviously what you are going to switch access etc and of course finally back up powe supply

low supply voltage levels brown out detection watch dog detection and may be even sleep functions keeping current consumption as low as possible if there is no interaction from user

You might within the above consider audible, visual and possibly raising telephone calls sms messages emails and other forms of identifying breach

If you are dealing with software interfaces for example software keys with usb interface,serial interface, parrallel interface How ever or what evere your final implementation Then obviously you would also need to take into account this framework as well

Those a few ideas for you to get started with

thanks sir .

I am want use it with lcd ,4x3 keyboard and internal eeprom (4 charcter only ) ..

No worries welcome Im producing a similar project myself becuase im so pivved at the lack of know how expressed by banks, so called government security and pivved off at being ripped a the time myself whilst watching one company collapse after another because they dont listen or take any note or of advice that both networking engineers give them or some of my collegues who have had years of experiance in many of these fields

Not to worry I guess one day they will when its too late as usual

So your first exorsize is as follows if you want to learn how to do this is

Write a programe in c using arrays to take input from keybourd and store four random numbers of your own choice in the array

At the end of your four choices print out the array to the console or screen both mean the same

Learn how to do this first then come back to me and ill give you another exorsise to carry out which will teach you the basics of what you want to do

Yes thanks sir
I have a header file to read the key which , stroked

First of all learn how to write a pc application using a c compiler There are free c compilers available for netbeans ide and also oracle and also Codeblocks which is the user ide free for download from the net

If you cant manage this then perform the exorsise ive given you in javascript with a simple html page which you can use notepad for or if your running linux or unix you can use vi to edit and contruct your code in

The idea is to learn basics first before you try and jump into the deepend not knowing anything about arrays keypad matrices, registers,bytes, words,unisigned signed binary notation, hex, sfrs, etc etc etc etc God alone knows how much you need to know and understand before you attempt mission impossible

So lets start with the basics first shall we Phew! !! I think i need a cold shower too cool off

I want to writ it in AVR Studio ?

Forget about avr studio at the moment Just do exactly as ive asked you to do and then avr studio wont be any difficulty what so ever Off you go

Please no one is to give him the answers I have reasons for this He wont learn anything at all by giving him the answers If the site will see me through this Cheers Mark