Radio communication thats cheap?

[Bradley1234]

Is there something similar to RFID systems that can do cheap, short distance
radio communication?

the setup has to be very cheap, like about $1 in parts that can be stuck
onto items like a barcode tag, then when passed near a scanner if the stored
code is a match it can transmit something back

Is there a simple radio technique for up to 10 feet or so where a $1 circuit
could hear the radio and if it matched some internal # hardwired, it could
transmit back some simple 8-bit response?

The bit width isnt as important as how to transmit (circuitry) and how a
cheap circuit can hear and react. Its similar to an RFID application, cant
interfere with cell phones or computers

The transmitter side can be more complicated but the receiver thing has to
be disposable

thanks

 

[Ian Stirling]

Bradley1234 <someone@yahoo.com> wrote:

Is there something similar to RFID systems that can do cheap, short distance
radio communication?

the setup has to be very cheap, like about $1 in parts that can be stuck
onto items like a barcode tag, then when passed near a scanner if the stored
code is a match it can transmit something back

Is there a simple radio technique for up to 10 feet or so where a $1 circuit
could hear the radio and if it matched some internal # hardwired, it could
transmit back some simple 8-bit response?

Some security tags some close to that price.
A number of coils, tuned by lasering off bridges might work.
You pretty much need the device to go through a sensing coil, such as an exi.

 

[Bradley1234]

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:8aBId.13911$wZ2.4934@newssvr13.news.prodigy.com...

Hi Bradley,

Is there something similar to RFID systems that can do cheap, short
distance
radio communication?

the setup has to be very cheap, like about $1 in parts that can be stuck
onto items like a barcode tag, then when passed near a scanner if the
stored
code is a match it can transmit something back

Is there a simple radio technique for up to 10 feet or so where a $1
circuit
could hear the radio and if it matched some internal # hardwired, it
could
transmit back some simple 8-bit response?

The bit width isnt as important as how to transmit (circuitry) and how a
cheap circuit can hear and react. Its similar to an RFID application,
cant
interfere with cell phones or computers

The transmitter side can be more complicated but the receiver thing has
to
be disposable



From your description above (...it can transmit something back...) it
seems there is no receiver but what you really want on the tag is a
transceiver.

Have you looked at Bluetooth?

Also, there is the not so trivial issue of supplying power to the tag
unit. While a little lithium cell might fit the cost bill, there can be
problems related to disposing of the 'disposable'. Environmental
regulations, safety etc.

Regards, Joerg

http://www.analogconsultants.com

HI Joerg,

What will work for the first part of this is if the remote part just
receives, if it can receive? Ill worry about the transceiver later

Bluetooth seems to be similar? to the ethernet over wireless protocol?
802.11B ?

Thats overkill in this application, if the data rate is 2K baud? Thats
plenty fast. The power part is solved, not an issue, lithium cells should
be safe for normal disposal in public landfills if I recall, but I wouldnt,
better to recycle.

All I want is to transmit something in an on/off code like NRZ, modulate an
rf signal so that its level is stronger/weaker, maybe 4 unique levels

The uhf remote control idea would fit the application, it should handle the
data rate. Seems like a person could use a 555 timer chip to send the
signal for radio?

Its the radio part that throws me, Ive got nothing to create this from
scratch and if I ever knew how, have forgotten.

 

Just a tidbit from the web with info about passive transpoders and
such:
http://rapidttp.com/transponder/

 

[Joel Kolstad]

Joerg,

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:8aBId.13911> From your description above (...it can transmit something
back...) it

seems there is no receiver but what you really want on the tag is a
transceiver.

I don't think he does -- all he wanted was to get an ID back from the chip,
and passive RFID tags usually do this by 'shorting out' the incoming field
for one bit (say 0) and not the other (this really is done by placing a
partially shorting the antenna terminals...). The drop is field strength is
detected by a circuit similar to a grid dip meter.

 

[Bradley1234]

From your description above (...it can transmit something

back...) it
seems there is no receiver but what you really want on the tag is a
transceiver.

I don't think he does -- all he wanted was to get an ID back from the
chip,
and passive RFID tags usually do this by 'shorting out' the incoming field
for one bit (say 0) and not the other (this really is done by placing a
partially shorting the antenna terminals...). The drop is field strength
is
detected by a circuit similar to a grid dip meter.

Right, just need the most basic radio transmission. Did more study its NOT
passive RFID Im looking for, but active with a battery.

Sending back, transceiver? not needed yet, receive only, 10 feet or so