Allowing an rfid tag to be programmed into a reader without using a PC

[orendacl]

Hello, For my rfid home door lock project I am going to declare one of my authorized tags as a "master". What I want to be able to do is have the microcontroller go into a mode called..."create_user:

In this mode the system will accept a new card swiped after it detects the master_tag.

It will then write the tag id number to EEPROM so that a new user tag has been authorized.
It should name it "NEW USER 1".

I wil also want to be able to remove a card. The latter is tougher as typically removing a card means it must have been lost.
...Need help.
Thanks guys.

[JonnyMac]

You understand this is a pretty complicated programming project and we'll only be able to give you guidance, right?

1st things 1st... how much BS2 programming experience to you have?  Have you decided all of your IO and can you map that?  Creating database type apps is not terribly easy in the BASIC Stamp, I know because I've done it once or twice.  What I suggest is that you create a max list of entries and mark then as "not used" with a bogus set of digits (e.g., $FF, $FF, $FF, $FF...).  In another location you can store the number of entries used.  The real problem comes when you have six entries and want to delete #4.  What you need to do is copy 5 to 4, 6 to 5, then mark #6 as not used, then update

Again... this is a very big project and based on your experience will take several hours of hardcore programming.  We'll do what we can to guide you.

[orendacl]

Hello, John. I am aware of the complexity of the project. Remember JFK's comment.
No this is not rocket science but I am comforted to know that you are here. Why...I know OR think I know you. So, prior that, I bought a book from a fellow who in my assessment borrowed your code. I asked him or "his forum" for support and really got nowhere! (This was not the same questions I am asking now). At the time it was an elementary question.
At this stage of my project all I have left are the difficult things so yes it looks bad. Guidance is all I want. I expect to do this myself.
1st things 1st... how much BS2 programming experience to you have?  I taught myself basic programming and in elemtary school was top of my class. Now however am quite beginner again as dropped it - never owned a computer til 3 years ago.
Have you decided all of your IO and can you map that? = NO
Creating database type apps is not terribly easy in the BASIC Stamp, I know because I've done it once or twice.  What I suggest is that you create a max list of entries and mark then as "not used" with a bogus set of digits (e.g., $FF, $FF, $FF, $FF...).
THAT IS WHAT I EXPECTED...LET'S DROP THE NEGATE USER OPTION.
Lastly, sorry I wrote some of my answers in CAPS! That was to differentiate my shorts comments from your questions.

[orendacl]

Sorry guys, my comments were getting too long.

Please provide jsut links to websites that might help. I have been working on this for a week straight for about 8 hours a shot and have to move onto other things. I will update on my progress but if you can send me some hints to links what would it be?
Probably my biggest concern is can I detect a master_tag, and write to eeprom the new user tag.
Sounds easy.
As for the delete a user... ideally deleting a user means that the tag was lost. How can one logically delete a user of an unmarked tag when they can simpyl convince their wife - let me delete it with my pc.
First things first! In other words at this time I want to solve just the "how to add a user" without a pc. Swipe a master tag. BS2 recognizes the ID. User swipes a NEW tag. BS2 idnetifies that tag and writes it to EEPROM. Done.
BTW - this has been done in offshore units you can buy. I invested money in a book, a lock, a reader, an ic...costs me so far $100 dollars more than buying the nice offshore one. I have seen it... go figure that is what got me put out of a job was foreign trade. That means I have time on my hands too.

[JonnyMac]

Just to be clear, when you say BS2 you mean our Prop-2 controller, right?  I couldn't find you in or customer database.

[orendacl]

Hello. Sorry, my deepest apologies for not identifying relation in he terminology. I have a device called a basic stamp 2 that I obtained from a firm named Parallax.
My bad.... 

[BigRez]

Assuming the discussion continues for usage on a prop-2 from EFX-TEK ... ;D

In another location you can store the number of entries used.  The real problem comes when you have six entries and want to delete #4.  What you need to do is copy 5 to 4, 6 to 5, then mark #6 as not used, then update

I don't see it as being that complex... If we know we have 6 keys (or even 20) and are deleting #4, we just need to copy #6 (or the last one) to #4 and then move $FF to #6 (or the last one) and decrement the entries location.  There's no mention of keeping them in order.

The real problem is knowing that address #4 (or any other address) is the one you want to delete, especially without having the physical tag.  You could connect a serial display or use some LEDs and have a button to indicate the delete operation, and then have the display cycle through waiting for the delete button to be pressed.

[JonnyMac]

I am forced to lock this thread.  EFX-TEK is not, and cannot become, a general support arm for Parallax products.  We can only afford to support customers using what they have purchased from EFX-TEK.

Parallax has its own great support forums: forums.parallax.com