wireless questions please help!
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Posts: 46,084
On Thu, 8 Jun 2000, Steve Znavor wrote:
> I have this project where I input data and the stamp gives me the "answer"
> by outputting a code to me through the high/low command. For example this
> is some of the code....
> ONE:
> high 0
> pause 1000
> low 0
> run 0
>
> TWO:
> high 0
> pause 400
> low 0
> pause 250
> high 0
> pause 400
> low 0
> run 0
>
> as you can see for the stamp to tell me a answer of 1 the stamp will output
> +5v to a LED for 1 second and for the stamp to tell me an answer of 2 the
> stamp will output +5v to a LED for .4 seconds twice with .25 seconds in
> between each pulse. Now for my question: is there a way I can do this
> wireless? Do I need a stamp on the receiving end to decode this and then
> execute the instructions? I only need it to transmit on one end and receive
> on the other and it cannot be IR it has to be RF but i DO NOT want the range
> to be 220 feet as I saw on the parallax page I want it to be about 15 feet.
> So I guess I want RF wireless. Is it possible for RF to only transmit only
> 15 feet or does it always have that huge range? Also 1 last thing if I had
> a scanner could I detect this wireless transmission? Is it possible for
> this to be undetected? It operates at like 433 MHZ...could something pick
> up that high of a frequency? Please help
Steve
Not sure why you want it undetected. But yes, 433MHz can be
detected. Basic TSCM scanners can work up to 4-8GHz or so easy, and
your generic but relatively expensive scanner can go up to 2GHz also.
Somebody please correct me if I'm wrong.
If something is wireless, it can ALWAYS be located if someone
wants to find it, and knows how to.
If the idea is that no one find out what you are transmitting,
then try using an encrypted transmition instead.
And yes, you can decrease the maximum reliable range of an RF
transmitter several ways; sometimes just using a lower potential does the
trick, you can intentionally "mismount" and antenna, or use one which
is just plain wrong (small wire, for example).
Hope this helps you, have a nice afternoon,
Paul
>
>
>
> ________________________________________________________________________
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>
>
>
>
> I have this project where I input data and the stamp gives me the "answer"
> by outputting a code to me through the high/low command. For example this
> is some of the code....
> ONE:
> high 0
> pause 1000
> low 0
> run 0
>
> TWO:
> high 0
> pause 400
> low 0
> pause 250
> high 0
> pause 400
> low 0
> run 0
>
> as you can see for the stamp to tell me a answer of 1 the stamp will output
> +5v to a LED for 1 second and for the stamp to tell me an answer of 2 the
> stamp will output +5v to a LED for .4 seconds twice with .25 seconds in
> between each pulse. Now for my question: is there a way I can do this
> wireless? Do I need a stamp on the receiving end to decode this and then
> execute the instructions? I only need it to transmit on one end and receive
> on the other and it cannot be IR it has to be RF but i DO NOT want the range
> to be 220 feet as I saw on the parallax page I want it to be about 15 feet.
> So I guess I want RF wireless. Is it possible for RF to only transmit only
> 15 feet or does it always have that huge range? Also 1 last thing if I had
> a scanner could I detect this wireless transmission? Is it possible for
> this to be undetected? It operates at like 433 MHZ...could something pick
> up that high of a frequency? Please help
Steve
Not sure why you want it undetected. But yes, 433MHz can be
detected. Basic TSCM scanners can work up to 4-8GHz or so easy, and
your generic but relatively expensive scanner can go up to 2GHz also.
Somebody please correct me if I'm wrong.
If something is wireless, it can ALWAYS be located if someone
wants to find it, and knows how to.
If the idea is that no one find out what you are transmitting,
then try using an encrypted transmition instead.
And yes, you can decrease the maximum reliable range of an RF
transmitter several ways; sometimes just using a lower potential does the
trick, you can intentionally "mismount" and antenna, or use one which
is just plain wrong (small wire, for example).
Hope this helps you, have a nice afternoon,
Paul
>
>
>
> ________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
>
>
>
>
>
Comments
by outputting a code to me through the high/low command. For example this
is some of the code....
ONE:
high 0
pause 1000
low 0
run 0
TWO:
high 0
pause 400
low 0
pause 250
high 0
pause 400
low 0
run 0
as you can see for the stamp to tell me a answer of 1 the stamp will output
+5v to a LED for 1 second and for the stamp to tell me an answer of 2 the
stamp will output +5v to a LED for .4 seconds twice with .25 seconds in
between each pulse. Now for my question: is there a way I can do this
wireless? Do I need a stamp on the receiving end to decode this and then
execute the instructions? I only need it to transmit on one end and receive
on the other and it cannot be IR it has to be RF but i DO NOT want the range
to be 220 feet as I saw on the parallax page I want it to be about 15 feet.
So I guess I want RF wireless. Is it possible for RF to only transmit only
15 feet or does it always have that huge range? Also 1 last thing if I had
a scanner could I detect this wireless transmission? Is it possible for
this to be undetected? It operates at like 433 MHZ...could something pick
up that high of a frequency? Please help
Steve
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