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still looking RFID

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kevb

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Hi still looking
I want to use a RFID key fob system and interface it with a pic microprocessor.
For opening a gate for a large member ship club of around 200 members
The system will be a stand alone unit that can be programmed with laptop
Through RS323 or USB etc
New members joining and members resigning can be written into the code by associating member ship number with the RFID tag.
Do anyone now of a project such as this or a pic project that can be modified to do the job.

Regards kevin
 
I don't believe those readers and tags are secure. Better to use the HID tags and readers if finances or life/safety is involved. They are pretty easy to interface to. Also, the HID readers are designed to take a wide range of conditions. There was a project in either N&V or CCI about a year ago that used a PIC to interface them and a PC to manage the database.
 
rfid/pic still looking

Hi guys and thank you for your reply
These RFID readers are plenty full on the internet
But what I am looking for is a stand alone that can be updated with a pc
It is not practical to have a pc linked up continuously
At the moment I am using a 25 Mh stand alone unit that has a numerical keyboard
To input data.
But it is a logistical nightmare to program 200 positions the slightest glitch
And all 200 key fobs have to be recalled to reprogram the unit.
The member ship are losing faith fast
I am pretty good at design and constructing most things electronic but this is slightly out of my depth
This could be a very interesting project for you guys with the now how
 
lets start with your budget. How much do you want to spend for your gate controller? For about $400, you could put together a low end linux pc. For less, you could use a small sbc running linux. I'd use either a serial, usb or ethernet connection. Reading the tag reader is a piece of cake. Atmel has a really cheap little card based on the avr32 which has uClinux already installed - ngw100. I think it's like $75. You could build a PIC based system for less but I like the using linux since all the file system, communications, and so on is done. all you have to do is the application.

The gate manager is pretty simple, it just sits in a loop waiting for fob input. Use a simple flat file for the members fob data. An entry would look something like this
Code:
char member_name[64];
uchar permissions;
int fob_num;
When you get a valid fob number on the reader, scan the file for a match. If permissions says "ok", do your thing, what ever it is. I would log all attempted accesses. Don't put the fob numbers into the source code. that's the worst way to do it. Your basic program looks like this in C
Code:
while(TRUE){
    fob_num = get_fob_data();  // wait for data from reader
    if(valid_fob(fob_num)) {
        open_gate();
        log_fob(fob_num, VALID);
    } else
        log_fob(fob_num, INVALID);
}
You should be able to write down (or capture) all the fob numbers so recalls aren't necessary. In fact, your PC database should have the fob number and who it is assigned to. Then to update the member file in the controller, print a special report form that is exactly the flat file format. Then just upload it to the controller.

If you have networking available, then a lot of cool new features become possible.
 
Hi philba thank you for your reply
The system I have in mind is an off the shelf RFID reader a pic microcontroller with a small amount of components.
So as to keep it simple if it goes wrong I can fix it.
A small end pc or sbc is a bit like having a hammer to crack a nut
My problem is the code I Haven’t had much experience with it and not for many years
So I’m starting at the beginning
I have been looking a what I think is a good pic tutorial which should get me going
**broken link removed**

these are the type of RFID readers I have been interested in

http://www.ibtechnology.co.uk/

regards
 
have it your way but when they ask you for 10 new features you might have different point of view.

good luck.
 
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