[aprssig] APRS RFID reader?

[Robert Bruninga]

Duh!  That's it!!!  SOLVED! 

> That said you really don't need more range.. 
> Instead of putting the chips on their hats, 
> put them on their feet..

OK, wow, so obvious! we can now do this NOW...  The RFID tags I
found from Sparkfun are $1.76 and they look like a credit card.
Just slip them into the soles of your favorite HAM shoes!
http://www.sparkfun.com/commerce/product_info.php?products_id=83
10

I guess sensitive feet would find this irritating, but you could
buy the more expensive chip for $5 each and attach it
elsewhere..  I also need to find out how much of this plastic
card is RFID, and how much of it is just a card to be used for
other purposes.  Maybe we can just cut off the RFID portion
(much smaller?)...

I wonder how fast the readers can catch the tag?  With only a
10" range,  you have a small chance the foot will hit it, and a
much large chance that the foot will swing through it in abou
0.1 second.  I guess your door mat would need maybe SIX 10 inch
sensor fields for reasonable capture reliability?  Spread them
out so they cover the whole door mat area...

They are fixed coded, 32 bits. Or 4 bytes or 8 hex.  So, all we
need is an APRS message defined so that people can register
their APRS RFID card.  If your code is 1A 2B 3C 4D for example,
you just use your existing APRS system to send a message 

TO RFID 
MYID=1A2B3C4D

>From that moment on, the global APRS-IS system knows you!
And when you report for duty at the EOC, or ham club, or local
bar, everyone will know.  If you don't want them to know, jump
over the door mat!

Maybe the ARRL will start stocking ARRL "Name Boots"... Instead
of Name Tags...

Bob, WB4APR

 
> 
> Quoting Robert Bruninga <bruninga at usna.edu>:
> 
> > I still think APRS-RFID... Is a next thing for APRS
> > experimenting
> >
> > Every ham hat could have a $2 chip in it.
> >
> > Then we can tell who enters the clubhouse or EOC... (it gets
> > converted to APRS...)
> > See http://www.aprs.org/aprs-rfid.html
> >
> > Problem is, the maximum range reader I can find is only good
for
> > 10 inches max and it costs about $24:
> >
http://www.sparkfun.com/datasheets/Sensors/ID-12-Datasheet.pdf
> >
> > It has provisions for a  wind your own antenna but still can
> > only get to about 10 " (25cm).  But since hams are RF
> > experimenters, it would seem that we could improve on this.
One
> > sentence in the limited docs says that there has to be
enough
> > energy to activate the chip.  This implies to me that the
limit
> > is on the energy transmitted to the chip, not necessarily
the
> > read range.  Frequency is 125 KHz.
> >
> > To get reliable coverage for people walking through a door,
I
> > think we need about 48" range...
> >
> > Does anyone want to fill us in on the details?  I assume a
125
> > KHz carrier in the antenna coil provides the energy for the
RFID
> > chip (this can be scaled up... Just needs more power)...
But
> > then I guess it has some off cycles so the chip can send
back
> > the 32 bit code?
> >
> > Bob, WB4APR
> >
> >
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> >
> 
> 
>