RFID, hold card on reader?

Projects General Guidance
1

Question is how do I get and RFID (LF) to do two actions.

I want to use it for access control for my side door and arm / disarm my alarm panel.

The disarm and unlock the door is simple, just do that every time the card is swiped. the arm is what I am questioning. can I do a "hold" on the reader and program that to do a separate I/O?

So fast swipe = Disarm / unlock (no problem disarming if it is already disarmed.)
Long swipe (5 sec. or so) = Arm system

???

Thanks

2

Nothing? lol

3

Maybe use two separate reads within a certain time?

4

Perhaps two readers, and swipe left/right or right/left?

5

02660:
Question is how do I get and RFID (LF) to do two actions.

I want to use it for access control for my side door and arm / disarm my alarm panel.

The disarm and unlock the door is simple, just do that every time the card is swiped. the arm is what I am questioning.

Perhaps the program logic of your Arduino could be that if the alarm is already disarmed then the only logical thing it can do with a swipe is arm it (LEDs can show you the status and therefore what it is expecting your next action to be).

Therefore you will never swipe to disarm if the alarm is already disarmed because that would arm it?

It can still allow access to the side door (I'm assuming these are two unrelated actions)?

If I have this wrong do please feel free to clarify your requirements!

6

Got side tracked on this project...

Having never worked with readers other than plug and play systems. My question is more on the coding and reading if the cards.

What does the Arduino see in a typical reader, or one formatted to use Wiegand format?

If I just keep holding the card at the reader will it keep sending the data or does it only do it once? If it keeps sending I think I can just do an IF statement and check the elapsed time that a valid code was received with some hastiness built in for assurance.

7

If it's kind of a magnetic stripe card, it's read once when you move it through the reader. A RFID card can be read as long as it's close enough to the reader.

8

If I just keep holding the card at the reader will it keep sending the data or does it only do it once?

It depends entirely on the sort of reader you have. Some will and others won't and still others can be quizzed to see if a card is still present. There are even some readers with a card present output signal.

9

Grumpy_Mike:
It depends entirely on the sort of reader you have. Some will and others won't and still others can be quizzed to see if a card is still present. There are even some readers with a card present output signal.

Thanks, that was what I was looking for. Now the question becomes does anyone know if any that will allow me to know if the card is still present?

10

This one has a command you can send asking "card present". I have found that when there is a card every other ask will return the true situation.
So if you ask and it says yes, then next time you ask it will say no, but just ignore that and ask again to see if the card is still on the reader.

I think this one https://www.proto-pic.co.uk/rfid-reader-id-12la-125-khz.html?gclid=CIWj6-3Ixc8CFesp0wodAUoPeA has a specific card present output pin.