Searching \ for '[OT]: presence' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=presence
Search entire site for: 'presence'.

Exact match. Not showing close matches.
PICList Thread
'[OT]: presence'
2000\07\02@195710 by Tony Nixon

flavicon
picon face
Hi all,

Does anyone know of any techniques or web site info that may be used to
detect human presence in the near vicinity, 1-2 meters approx. The
detector could be mobile and operate either inside or outside.

--
Best regards

Tony

http://www.picnpoke.com
spam_OUTsalesTakeThisOuTspampicnpoke.com

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

2000\07\02@201715 by Tony Nixon

flavicon
picon face
David Harris wrote:
>
> Hi Tony -
>
> You might try this.  Its dead simple, so its worth a try.  I doubt it has
> the range you want.  I haven't tried it myself (yet), so tell me if you get
> it to work!

Sure is simple - nothing there :-)

> PS:  has anyone implemented ROMZap on a Dontronics 877 board?

No, but there will be a 28/40 pin ROMzap board available very soon. It
will be compatable with 16F870/1/2/3/4/6/7.

--
Best regards

Tony

http://www.picnpoke.com
.....salesKILLspamspam@spam@picnpoke.com

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

2000\07\02@233852 by Jinx

face picon face
> Does anyone know of any techniques or web site info that may be used to
> detect human presence in the near vicinity, 1-2 meters approx. The
> detector could be mobile and operate either inside or outside.
>
> Best regards
>
> Tony

For 360 degree detection disturbing a HF field works well. I made
one from (I believe) Electronics Australia some years ago. If you or
I can't find the exact circuit (I'll have a look) then that portion from a
Theremin would do too, same principle. Quite a few Theremin
circuits on the web to chose from (unstarted project of mine. Ironic
isn't it ? Things like that are "rainy day" tinkering, but it's been hosing
down so much lately don't feel like getting wet to get the bits)

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

2000\07\03@063717 by fernteix

flavicon
face
Hi Tony,

Any oscilator LC or RC with a small C could do it, if the electric field of
the C  is not confined. You can use a C made with 2 wires at some distance.
After is to use the perturbation in the frequency. You can also have 2
oscilators one with normal caps as reference. A nice device for a PIC.
Best Regards

Fernando

{Original Message removed}

2000\07\03@123933 by Dan Michaels

flavicon
face
Fernando wrote:

>Any oscilator LC or RC with a small C could do it, if the electric field of
>the C  is not confined. You can use a C made with 2 wires at some distance.
>After is to use the perturbation in the frequency. You can also have 2
>oscilators one with normal caps as reference. A nice device for a PIC.
>Best Regards
>

How important is it to have high-Q in the LC circuit, for this
circuit to have adequate range sensitivity? And is oscillator
stability an issue that has to be worried about?

- DanM

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@154834 by Peter L. Peres

picon face
>1-2 meters

A PIR type device is the best solution imho. A reflected IR beam can also
be used (use modulated IR). A grid dip based RF field detector would
require a lot of filtering to make the output somewhat reliable. A small
dog who knows the approaching person seems ideal to me ;-) You need to
calculate the power consumption in Whiskas/hour and MTBF between when
you walk it <G>.

The dip meter solution will not likely pass any EC/FCC/anywhere test and
may cause some interference with local people (esp. if they listen to DX
shortwave with cheap radios - which most people seem to do).

Modulated IR reflective sensing also works at 2 meters. Ultrasonic bounce
requires less power and also works at 2 meters.

Only PIR can discriminate people from other approaching things, and only
approximately. As I said, a small dog would be ideal. Think embedded
Chihuahua (sp?) ;-).

Peter

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@164539 by Andrew Seddon

picon face
I remember seeing an article in Elektor Electronics that used a microwave
sensor. It was incredibly simple for what it did as the chip had all the RF
on board and just output a voltage proportional to the doppler shift or
something. Apparantly it worked at microwave frequencies and upto 10m.

I`d give you more info but the magazine is long gone. You may want to look
on the internet for it.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@174646 by fernteix

flavicon
face
Hi Michaels,

The RC seems the most interesting to interface with PICs. If we disturb the
distribution of an electrical field between two wires we change the capacity
(we are a third wire...). The period of a RC oscilator = k RC. If we use
small values for C we can have higher percentage of change in C, with our
presence, so the same  in change in period of the oscilator. The period can
be mesured easily with timer0 or timer 1, so I think would be easy ( for a
slow and simple yes/no device)  to do with PICs a presence detector for very
small range. Perhaps the RC clock of the PIC itself , without C or with a
small value of C??
For LC the same idea could be used ( a square root of LC in the formula),
but would be less easy.
It was only an idea, not tested...
Best Regards

Fernando


>Fernando wrote:
>
>>Any oscilator LC or RC with a small C could do it, if the electric field
of
>>the C  is not confined. You can use a C made with 2 wires at some
distance.
{Quote hidden}

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@192531 by Tony Nixon

flavicon
picon face
Thanks for the ideas folks.

They give me something to think about.

--
Best regards

Tony

http://www.picnpoke.com
salesspamKILLspampicnpoke.com

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@210241 by Dan Michaels

flavicon
face
Andrew Seddon wrote:
>I remember seeing an article in Elektor Electronics that used a microwave
>sensor. It was incredibly simple for what it did as the chip had all the RF
>on board and just output a voltage proportional to the doppler shift or
>something. Apparantly it worked at microwave frequencies and upto 10m.
......
>

Could this possibly have been using the MIR - micropower impulse
radar device?

http://lasers.llnl.gov/lasers/idp/mir/mir.html

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@210241 by Dan Michaels

flavicon
face
Andrew Seddon wrote:
>I remember seeing an article in Elektor Electronics that used a microwave
>sensor. It was incredibly simple for what it did as the chip had all the RF
>on board and just output a voltage proportional to the doppler shift or
>something. Apparantly it worked at microwave frequencies and upto 10m.
......
>

Could this possibly have been using the MIR - micropower impulse
radar device?

http://lasers.llnl.gov/lasers/idp/mir/mir.html

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\04@020216 by Michael Wieser

flavicon
face
At http://www.conrad.de you can do a search about Radarsensor
or Doppler-Radarsensor, which results in 2 hits about something like that....



>I remember seeing an article in Elektor Electronics that used a microwave
>sensor. It was incredibly simple for what it did as the chip had all the RF
>on board and just output a voltage proportional to the doppler shift or
>something. Apparantly it worked at microwave frequencies and upto 10m.
>
>I`d give you more info but the magazine is long gone. You may want to look
>on the internet for it.
>

Michael Wieser
.....m.k.wKILLspamspam.....nextra.at

Service and Audiodesign

--
http://www.piclist.com hint: To leave the PICList
EraseMEpiclist-unsubscribe-requestspam_OUTspamTakeThisOuTmitvma.mit.edu>

2000\07\04@020216 by Michael Wieser

flavicon
face
At http://www.conrad.de you can do a search about Radarsensor
or Doppler-Radarsensor, which results in 2 hits about something like that....



>I remember seeing an article in Elektor Electronics that used a microwave
>sensor. It was incredibly simple for what it did as the chip had all the RF
>on board and just output a voltage proportional to the doppler shift or
>something. Apparantly it worked at microwave frequencies and upto 10m.
>
>I`d give you more info but the magazine is long gone. You may want to look
>on the internet for it.
>

Michael Wieser
m.k.wspamspam_OUTnextra.at

Service and Audiodesign

--
http://www.piclist.com hint: To leave the PICList
@spam@piclist-unsubscribe-requestKILLspamspammitvma.mit.edu>

2000\07\04@093637 by Russell McMahon

picon face
>>I remember seeing an article in Elektor Electronics that used a microwave
>>sensor. It was incredibly simple for what it did as the chip had all the
RF
>>on board and just output a voltage proportional to the Doppler shift or
>>something. Apparently it worked at microwave frequencies and upto 10m.
>>
>>I`d give you more info but the magazine is long gone. You may want to look
>>on the internet for it.
>>
>
>Michael Wieser
>KILLspamm.k.wKILLspamspamnextra.at


Probably

       http://www.getradar.com

Sandia labs (or was it La Li labs?)
Very dear to get into (?$US30,000?) and sp[ecial agreements etc but unit
price is small ($US10 and falling somemyears ago).
When all is said and done it's just a small version of the things used as
door openers a decade ago (and sometimes now) but on a single chip. Nice
technology but no real gee whiz stuff. Wireless workd did a unit way back
when that used two transistors ina  push pull osc on pcb and a tinpalte
box/wave guide and it seemed to do about as well as the Philips Gunn diode
modules which have die cast Zinc? (AFAIR) waveguides.


RM

>At http://www.conrad.de you can do a search about Radarsensor
>or Doppler-Radarsensor, which results in 2 hits about something like
that....

--
http://www.piclist.com hint: To leave the PICList
RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu>

2000\07\04@143531 by Peter L. Peres

picon face
>microwave

This uses (almost) no chips, but you can buy them ready made. Some of the
door openers in industrial environments use this instead of PIR (forklift
trucks have too low IR signature for PIR). They use horn antennas (two)
and are directional. You could point one to the tip of a reflector cone to
get 360 degree coverage. Usually work at 10 GHz so they will also detect
other approaching and moving objects (fences, bushes, garbage, birds etc).
Only PIR does not see these.

Peter

--
http://www.piclist.com hint: To leave the PICList
spamBeGonepiclist-unsubscribe-requestspamBeGonespammitvma.mit.edu>

2000\07\05@121350 by goflo

flavicon
face
Russell McMahon wrote:
> Sandia labs (or was it La Li labs?)

LLNL

> Very dear to get into (?$US30,000?) and sp[ecial agreements etc

$50K when I looked into it in '96. They seem inordinately
interested in who you are, and what you're up to...
They claim lots of licensees - Where are the products?
Very strange.

regards, Jack

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]: PIC only [EE]: engineering [OT]: off topic [AD]: advertisements

2000\07\06@104236 by Dan Larson

flavicon
face
Have a look a this 555 circuit using stray capacitance
for the RC and read by a PIC.

http://www.rdrop.com/users/marvin/

Select the "projects" link and scroll way down to the bottom
of the page.

Dan


On Mon, 3 Jul 2000 09:56:22 +1000, Tony Nixon wrote:

{Quote hidden}

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics

More... (looser matching)
- Last day of these posts
- In 2000 , 2001 only
- Today
- New search...