RFID

melazarus

Member
hi,
I would like to play around with RFID and picaxe. I have seen some RS232 interfaced RFID readers but I can't find any RFID writers that can be easily interfaced with a Picaxe.

Has anyone any experience with this?
 
G

Guest

Guest
Andrew" BrightSpark" has been involved with this here in NZ. I'll get him to post here. Stan
 

xstamp

Senior Member
Not sure I understand your distinction between RFID read and write units. My understanding is that an RFID interfaces normally operate in a read/write mode. Thats because most tags are passive devices without their own power source. They must be interrogated/energised by the RFID interface before transmitting information back to it.

 

melazarus

Member
What I mean with a RFID write unit is a device that can reprogram a RFID tag.
Most passive RFID tags have a static number that is supposed to be unique. But there exist also empty write once tags and tags that can be cleared and rewritten over and over again. This way you can store your own data on a RFID tag. (only a few bytes offcourse)

I have seen some beeing used in hotels but these devices are not realy cheap so I was thinking of making one myself with a Picaxe controller.
 
I find the ID12 device ideal for most projects. It can be linked up with just some jumpers on the back of the ID12 and treat it as a "Three Wire Device"

Bring back three wires to the PICAXE / proto board... +ve, -ve and it just spits out a unique 12 ASCII character 9600 baud sequence when ever a FOB comes within range. The standard tags are NZ$5 each and come as a FOB or key ring but flat cards and or cattle ear tags are becoming available.

I have set up an over clocked 5% detuned 08M to read the 12 x 9600bd ASCII digits sent out by the ID12 at 4800bd. This "halves" the number of digits but still works fine for student projects.

What the student wants to do with the 6 unique ASCII bytes is up to them. Some cards can be set up as "master" and allow hierarchical control of the logic in the program etc, time switches. I make the 6 digits play a tune so you can “hear” your own unique code as you log in.

http://picaxe08.orcon.net.nz//Photos/PICAXE/Proto/Data/RFID.jpg

http://picaxe08.orcon.net.nz//Photos/PICAXE/Proto/Data/RFID-sch.jpg

- Andrew

 

jmumby

Senior Member
Andrew,

How does the ID12 fare with implant tags like in a cat. Also where abouts in NZ do you source the ID12?

Cheers
 

melazarus

Member
Thanks everyone. I've just checked the site of ID Innovations and I see that they also have the ID-12WR. That is the writer version.

This is exactly what I need. For overcome the 9600 boud I'll use a PicAxe 28X at 16Mh.

Now I only need to fine a site where they sell these babies

thanks again

Edited by - melazarus on 06/04/2007 14:18:31
 
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