Searching \ for '[OT]: Proximity Sensor' 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/io/sensors.htm?key=sensor
Search entire site for: 'Proximity Sensor'.

Exact match. Not showing close matches.
PICList Thread
'[OT]: Proximity Sensor'
2001\01\17@201341 by Tony Nixon

flavicon
picon face
Hi all,

Does any one know of a proximity sensor/transmitter that could be worn
on a shirt pocket like an ID tag, and be able to be detected by a
receiver of some sort, up to 5 meters away?


--
Best regards

Tony

mICro's
http://www.picnpoke.com
spam_OUTsalesTakeThisOuTspampicnpoke.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\17@205524 by Stephen B Webb

flavicon
face
> Does any one know of a proximity sensor/transmitter that could be worn
> on a shirt pocket like an ID tag, and be able to be detected by a
> receiver of some sort, up to 5 meters away?

I don't know much about it, but the Microchip RFID products might give you
the functionality you want.

-Steve

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\18@102203 by mike

flavicon
face
On Thu, 18 Jan 2001 11:25:35 +1100, you wrote:

>Hi all,
>
>Does any one know of a proximity sensor/transmitter that could be worn
>on a shirt pocket like an ID tag, and be able to be detected by a
>receiver of some sort, up to 5 meters away?

I'd think infra-red might just be viable for this. RFID tags would
probably not have the range unless you used a BIG antenna. Short-range RF transmission may also be useable.

--
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


2001\01\18@232018 by Anand Dhuru

flavicon
face
How about the cheap RX/TX modules as made by Ming? They are very easy to
use, have a decent range, and can be coded by any protocol (even a self
designed-custom one).
To conserve battery on the transmitter (the actual ID Tag), you could
perhaps use a PIC that sleeps most of the time and just gives out a
transmission in a very short narrow burst every second or so.

Regards,

Anand.
{Original Message removed}

2001\01\19@172055 by Peter L. Peres

picon face
Try infrared challenge/response. 5 meters is a problem with RF because it
goes through walls and you can have serious problems with this (hint:
building level/storey height is abt. 3-3.5m, your 5m range will reach up
and down beyond that ;-) ).

Peter

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


2001\01\21@174713 by Tony Nixon

flavicon
picon face
"Peter L. Peres" wrote:
>
> Try infrared challenge/response. 5 meters is a problem with RF because it
> goes through walls and you can have serious problems with this (hint:
> building level/storey height is abt. 3-3.5m, your 5m range will reach up
> and down beyond that ;-) ).
>
> Peter

Good point, I didn't think of that.

What I need to do is detect a human presence in a range of up to 10
meters max. The person would be in line of sight.

It would be ideal if the 'target device' is passive (ie. requires no
batteries).

Possibly something as simple as fluorescent (or similar) strip(s) sewn
into a garment that can be 'seen' by a detector. The only problem is the
different lighting situations.

--
Best regards

Tony

mICro's
http://www.picnpoke.com
.....salesKILLspamspam@spam@picnpoke.com

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


2001\01\22@004513 by Russell McMahon

picon face
What I need to do is detect a human presence in a range of up to 10
meters max. The person would be in line of sight.

It would be ideal if the 'target device' is passive (ie. requires no
batteries).

Possibly something as simple as fluorescent (or similar) strip(s) sewn
into a garment that can be 'seen' by a detector. The only problem is the
different lighting situations

______________________________
.
Consider doppler radar.
These were all the rage for door openers before PIRs took over.
Range depends on power and aerial.
While you can use the commercial Gunn effect oscillator commercial designs
eg Philips you can roll your own using eg a SAW oscillator.
A Wireless World article many years ago (70's? 80's?) used a push pull
oscillator on PCB.

Here's a trad secret you won't hear about anywhere in the literature that
I'm aware of
Filter the return signal with a bandpass filter to detect the "joint
articulation frequency" from human joints. I forget the frequency but AFAIR
its around 17 to 25 Hz range. Playing will indicate a very human specific
response frequency. This helps eliminate false triggering from curtains,
doors, animals falling objects etc.

Aerial beam pattern will assist detection of only what you want to see.
Getting a wide or multidirectional aperture may be "interesting".


regards



     Russell McMahon
_____________________________

What can one man* do?
Donate food daily free !!! -  http://www.thehungersite.com/
Donate Vitamin A!  http://www.thechildsurvivalsite.com/
http://www.rawa.com  - one perspective on Afghanistan
http://www.changingourworld.com    http://www.easttimor.com   http://www.sudan.com

(* - or woman, child or internet enabled intelligent entity :-))

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\22@045329 by Vasile Surducan

flavicon
face
I'm afraid without batteries is impossible...
10m distance, with cheap devices seems only
PIR detector  or IR barier detector.
Microvawe base radar detector is expensive ( see Paradox PIR/microvawe
moovement sensor )
Vasile

On Mon, 22 Jan 2001, Russell McMahon wrote:

{Quote hidden}

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\22@151346 by Peter L. Peres

picon face
At 10m even challenge/response with an active tag is interesting. Is there
a guarantee that the targets appear one by one ? Is there clutter in the
area (equipment, lights, other people, moving machinery) ?

If you use a moderately expensive movable camera head, camera, and
computer (maybe you can wedge a PIC into it at the camera control end)
then it is possible to implement a system that will locate a person,
locate a tag on the person, and read a barcode or even normal lettered
text (OCR) off it (all by itself). Is this passive enough for the tags ? <g>

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\22@165543 by Tony Nixon

flavicon
picon face
"Peter L. Peres" wrote:
>
> At 10m even challenge/response with an active tag is interesting. Is there
> a guarantee that the targets appear one by one ? Is there clutter in the
> area (equipment, lights, other people, moving machinery) ?
>
> If you use a moderately expensive movable camera head, camera, and
> computer (maybe you can wedge a PIC into it at the camera control end)
> then it is possible to implement a system that will locate a person,
> locate a tag on the person, and read a barcode or even normal lettered
> text (OCR) off it (all by itself). Is this passive enough for the tags ? <g>
>
> Peter

Interesting idea.

It appears (as usuall) that the whole story was not unfolded and now it
appears there may be obstacles which is going to make the whole process
different. Back to the think tank.

Thanks to all who offerred help.

--
Best regards

Tony

mICro's
http://www.picnpoke.com
.....salesKILLspamspam.....picnpoke.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\01\23@061833 by Alan B. Pearce

face picon face
>At 10m even challenge/response with an active tag is interesting. Is there
>a guarantee that the targets appear one by one ? Is there clutter in the
>area (equipment, lights, other people, moving machinery) ?

How is it done on those things that are supposed to be able to read a trolley
load of groceries that have a transponder in every packet? I have seen items on
TV where these are demonstrated, but do not know of it being used commercially
yet.

--
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


2001\01\25@140706 by Peter L. Peres

picon face
>trolleys

I have no idea but there are about three ways:

1. Make the trolleys pass in a single file through a restricted place
(like between two checkout counters).
2. Use a ground loop (buried in the floor and ceiling) to do the same (the
loop being small will trip on one trolley).
3. Use directional receivers (least likely).

Ok, then you can bill certain items twice and blame it on the system if
you get caught.

Peter

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email EraseMElistservspam_OUTspamTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body



'[OT]: Proximity Sensor'
2001\02\27@095254 by Mark Moldavsky
flavicon
face
Dear Mr. Russel,

It was very interesting to read your opinion about the real problem
to differ by "Doppler effect technology" a human motion from any
other motions (animals, curtains, doors e t.c.). But, unfortunately
it is a little bit difficult to understand the principle you explained
about. As we work in this domain it is desire you would explain
the same issue, but more detailed. Otherwise, would you like
to recommend us any books or articles, were it is described.

Best regards,

Mark Moldavsky, Ph.D.

Russell McMahon 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


2001\02\27@102842 by t F. Touchton

flavicon
face
part 1 4832 bytes content-type:text/plain; charset=us-asciiSorry for the delayed response... I did what you are trying to do for pet
containment.  There was a general patent filed, but to the best of my knowledge
it was abandoned.

I used a B/W camera, IR filtering and IR illumination.  An IR reflector was
placed on the pooch... camera looked down from above.  This gave a definite
"white" blip.  Used a sync separator to analyze what row the blip was in, and
looked at how far over it was in the sweep.  This gave X and Y coordinates for
mapping and other stuff (all done with a PIC, of course!).  Worked great with a
burning cigarette too.

Also implemented with a small IR emitter flashing a particular pattern...
pattern was analyzed on camera end to identify.

Of course.. this only works line of sight, but it is relatively cheap to
implement.... camera's were about $60 (US).. and the rest couldn't have been
more than about $50 (onesy - twosy).. not sure of the cost on the IR
illumination (it might have been more).




|--------+----------------------->
|        |          Mark         |
|        |          Moldavsky    |
|        |          <mmoldav@VISO|
|        |          NIC.COM>     |
|        |                       |
|        |          02/27/01     |
|        |          09:58 AM     |
|        |          Please       |
|        |          respond to   |
|        |          pic          |
|        |          microcontroll|
|        |          er discussion|
|        |          list         |
|        |                       |
|--------+----------------------->
 >----------------------------------------------------------------------------|
 |                                                                            |
 |       To:     PICLISTspamspam_OUTMITVMA.MIT.EDU                                       |
 |       cc:     (bcc: Scott Touchton/US/UNIPHASE)                            |
 |       Subject:     Re: [OT]: Proximity Sensor                              |
 >----------------------------------------------------------------------------|





Dear Mr. Russel,

It was very interesting to read your opinion about the real problem
to differ by "Doppler effect technology" a human motion from any
other motions (animals, curtains, doors e t.c.). But, unfortunately
it is a little bit difficult to understand the principle you explained
about. As we work in this domain it is desire you would explain
the same issue, but more detailed. Otherwise, would you like
to recommend us any books or articles, were it is described.

Best regards,

Mark Moldavsky, Ph.D.

Russell McMahon 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




part 2 4544 bytes content-type:application/octet-stream; (decode)

part 3 144 bytes
--
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 2001 , 2002 only
- Today
- New search...