Searching \ for '[EE] Proximity Sensors' 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 Sensors'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Proximity Sensors'
2012\02\20@174217 by David Duffy (AVD)

flavicon
face
Has anyone here done much work with proximity sensors?  I am looking to trigger an event when someone stands in front of (or walks past) a specific area in a retail environment.  The sensing must be done from one side only (no beam break methods).

The sensing range would need to be approx 200mm - 1000mm (8" - 40").  The horizontal detection width would need to be approx 500mm (20") at end of the range I guess.  There would be multiple sensors, spaced at approx 600mm - 900mm (24" - 36") intervals.

There is nowhere to mount the sensors apart from near the floor or *maybe* on the wall higher up.  Ideally the sensors need to stand up to a bit of abuse from knocks and maybe a splash from a cleaners mop.

Typical machinery proximity sensors would be easy to mount, but seem to be mostly very short range.  Ambient light can change somewhat so shadow detection would not be suitable I suspect.

I had thought about ultrasonic "range finders" (as used in robotics) but they would probably interact when use this close together.  They also wouldn't stand up to the abuse they'd cop being mounted down low.

I think typical PIRs are going to be too coarse, but maybe there are better ones than what I've seen so far?
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@175344 by Djula Djarmati

flavicon
On 20-Feb-12 23:42, David Duffy (AVD) wrote:
> Has anyone here done much work with proximity sensors?  I am looking to
> trigger an event when someone stands in front of (or walks past) a
> specific area in a retail environment.  The sensing must be done from
> one side only (no beam break methods).

Sharp IR proximity sensors?

<http://www.schukat.com/schukat/schukat_cms_en.nsf/index/warengruppe?OpenDocument&wg=A2425&refDoc=CMSB5525456731BA303C125711E004F62C5>

Djula

{Quote hidden}

2012\02\20@175740 by Marcel Duchamp

picon face
On 2/20/2012 2:42 PM, David Duffy (AVD) wrote:
{Quote hidden}

Multiple sensors can be used if you control them all.  Just use time division multiplexing - only one on at a time. For the other requirements, I would look at IR transmitters/receivers.

What is the penalty for false positives

2012\02\20@175959 by Nily

flavicon
face
Did you check doppler modules ?

-----Mensaje original-----
De: spam_OUTpiclist-bouncesTakeThisOuTspammit.edu [.....piclist-bouncesKILLspamspam@spam@mit.edu]En nombre de
David Duffy (AVD)
Enviado el: Monday, February 20, 2012 2:42 PM
Para: PicList
Asunto: [EE] Proximity Sensors


Has anyone here done much work with proximity sensors?  I am looking to trigger an event when someone stands in front of (or walks past) a specific area in a retail environment.  The sensing must be done from one side only (no beam break methods).

The sensing range would need to be approx 200mm - 1000mm (8" - 40").  The horizontal detection width would need to be approx 500mm (20") at end of the range I guess.  There would be multiple sensors, spaced at approx 600mm - 900mm (24" - 36") intervals.

There is nowhere to mount the sensors apart from near the floor or *maybe* on the wall higher up.  Ideally the sensors need to stand up to a bit of abuse from knocks and maybe a splash from a cleaners mop.

Typical machinery proximity sensors would be easy to mount, but seem to be mostly very short range.  Ambient light can change somewhat so shadow detection would not be suitable I suspect.

I had thought about ultrasonic "range finders" (as used in robotics) but they would probably interact when use this close together.  They also wouldn't stand up to the abuse they'd cop being mounted down low.

I think typical PIRs are going to be too coarse, but maybe there are better ones than what I've seen so far?
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@180453 by Nily
flavicon
face
Look at this item 120782820889 sold by eBay.

Says detection 20 meters...

-----Mensaje original-----
De: piclist-bouncesspamKILLspammit.edu [.....piclist-bouncesKILLspamspam.....mit.edu]En nombre de
David Duffy (AVD)
Enviado el: Monday, February 20, 2012 2:42 PM
Para: PicList
Asunto: [EE] Proximity Sensors


Has anyone here done much work with proximity sensors?  I am looking to trigger an event when someone stands in front of (or walks past) a specific area in a retail environment.  The sensing must be done from one side only (no beam break methods).

The sensing range would need to be approx 200mm - 1000mm (8" - 40").  The horizontal detection width would need to be approx 500mm (20") at end of the range I guess.  There would be multiple sensors, spaced at approx 600mm - 900mm (24" - 36") intervals.

There is nowhere to mount the sensors apart from near the floor or *maybe* on the wall higher up.  Ideally the sensors need to stand up to a bit of abuse from knocks and maybe a splash from a cleaners mop.

Typical machinery proximity sensors would be easy to mount, but seem to be mostly very short range.  Ambient light can change somewhat so shadow detection would not be suitable I suspect.

I had thought about ultrasonic "range finders" (as used in robotics) but they would probably interact when use this close together.  They also wouldn't stand up to the abuse they'd cop being mounted down low.

I think typical PIRs are going to be too coarse, but maybe there are better ones than what I've seen so far?
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@184105 by IVP

face picon face
part 1 1647 bytes content-type:text/plain; charset="iso-8859-1" (decoded quoted-printable)

> I think typical PIRs are going to be too coarse

I've found PIR isn't too bad, and use it for detection at a variety of
ranges and angles. A bare PIR sensor has quite a short range, a
couple of hundred mm, which can be substantially increased by a PIR
Fresnel lens. The style and size of the lens is important wrt detection,
as the plastic itself is the front-end filter, removing all but heat infra-
red, and particular lens patterns are used for particular targets

eg http://www.infraotica.com/index_files/Page380.htm

You might have noticed my post about curtain lenses a couple of
days ago ( [OT] PIR curtain lens ). In the right conditions fairly
reliable detection is many many metres. Note that PIR sensors
contain two elements and the output is the difference, greatest when
the movement is perpendicular to the orientation of the elements (ie
a target moving horizontally will produce the best output from
vertically aligned elements)

dV/dT can be used to differentiate between a moving object and a
changing environment (drafts, area heating/cooling etc). A low-cut
filter is often sufficient to remove < 3-4Hz. Can be done with op-amps
or in software to determine velocity

Compare the two attached schematics. pir_180 is very low-power,
motion_detector is from a security light. Both have high gain at LF

Another method I've tried is RF interference, although not practical
for my battery-powered applications. Similar to how a Theremin works.
An antenna is fed with RF and any disturbance to the field is detected

Pretty much immune to almost everything except movement

Joe

part 2 9011 bytes content-type:image/gif; name="motion_detector.gif" (decode)


part 3 6495 bytes content-type:image/gif; name="pir_180.gif" (decode)


part 4 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
mailman.mit.edu/mailman/listinfo/piclist

2012\02\20@184206 by Nily

flavicon
face
David

www.suntekstore.com/goods-14001970-Wireless+Module+Doppler+Radar+Micr
owave+Motion+Sensor.html

This link has some data and schematics. Look at " document download ".

Cheers

Rodolfo

-----Mensaje original-----
De: EraseMEpiclist-bouncesspam_OUTspamTakeThisOuTmit.edu [piclist-bouncesspamspam_OUTmit.edu]En nombre de
Nily
Enviado el: Monday, February 20, 2012 3:05 PM
Para: Microcontroller discussion list - Public.
Asunto: RE: [EE] Proximity Sensors


Look at this item 120782820889 sold by eBay.

Says detection 20 meters...

-----Mensaje original-----
De: @spam@piclist-bouncesKILLspamspammit.edu [KILLspampiclist-bouncesKILLspamspammit.edu]En nombre de
David Duffy (AVD)
Enviado el: Monday, February 20, 2012 2:42 PM
Para: PicList
Asunto: [EE] Proximity Sensors


Has anyone here done much work with proximity sensors?  I am looking to
trigger an event when someone stands in front of (or walks past) a
specific area in a retail environment.  The sensing must be done from
one side only (no beam break methods).

The sensing range would need to be approx 200mm - 1000mm (8" - 40").
The horizontal detection width would need to be approx 500mm (20") at
end of the range I guess.  There would be multiple sensors, spaced at
approx 600mm - 900mm (24" - 36") intervals.

There is nowhere to mount the sensors apart from near the floor or
*maybe* on the wall higher up.  Ideally the sensors need to stand up to
a bit of abuse from knocks and maybe a splash from a cleaners mop.

Typical machinery proximity sensors would be easy to mount, but seem to
be mostly very short range.  Ambient light can change somewhat so shadow
detection would not be suitable I suspect.

I had thought about ultrasonic "range finders" (as used in robotics) but
they would probably interact when use this close together.  They also
wouldn't stand up to the abuse they'd cop being mounted down low.

I think typical PIRs are going to be too coarse, but maybe there are
better ones than what I've seen so far?
David...

--
___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@200043 by David Duffy (AVD)

flavicon
face
On 21/02/2012 8:57 AM, Marcel Duchamp wrote:
> On 2/20/2012 2:42 PM, David Duffy (AVD) wrote:
>> Has anyone here done much work with proximity sensors?  I am looking to
>> trigger an event when someone stands in front of (or walks past) a
>> specific area in a retail environment.  The sensing must be done from
>> one side only (no beam break methods).
>>
> Multiple sensors can be used if you control them all.  Just use time
> division multiplexing - only one on at a time. For the other
> requirements, I would look at IR transmitters/receivers.
>
> What is the penalty for false positives?

That's a fair point about multiplexing the sensors.  I was envisaging a central controller board that processes up to 8 sensors.  Larger installations would have multiple controller boards, or maybe an expander board.

There is no serious consequence of a false positive.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@200134 by David Duffy (AVD)

flavicon
face
On 21/02/2012 8:55 AM, Djula Djarmati wrote:
> On 20-Feb-12 23:42, David Duffy (AVD) wrote:
>> Has anyone here done much work with proximity sensors?  I am looking to
>> trigger an event when someone stands in front of (or walks past) a
>> specific area in a retail environment.  The sensing must be done from
>> one side only (no beam break methods).
> Sharp IR proximity sensors?
>
> <http://www.schukat.com/schukat/schukat_cms_en.nsf/index/warengruppe?OpenDocument&wg=A2425&refDoc=CMSB5525456731BA303C125711E004F62C5>
>
>

Thanks for the link.  I might get a couple of those style sensors to experiment with.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@200357 by David Duffy (AVD)

flavicon
face
Thanks for the link.  I checked them out but they have a min range of 3 metres, which will cause triggering by people way outside the target range.
David...

On 21/02/2012 9:42 AM, Nily wrote:
{Quote hidden}

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@200950 by David Duffy (AVD)

flavicon
face
On 21/02/2012 9:40 AM, IVP wrote:
>> I think typical PIRs are going to be too coarse
>
> I've found PIR isn't too bad, and use it for detection at a variety of
> ranges and angles. A bare PIR sensor has quite a short range, a
> couple of hundred mm, which can be substantially increased by a PIR
> Fresnel lens. The style and size of the lens is important wrt detection,
> as the plastic itself is the front-end filter, removing all but heat
> infra-
> red, and particular lens patterns are used for particular targets

Hi Joe,
I might revisit the PIR modules.  Finding something sturdy enough as an off the shelf product is the ideal scenario.  We *could* build sensors, but I'd rather not just yet as it's just an idea with no commitment to bulk quantity yet.  If I could buy a ready to go sensor with a cable tail for under $50 in small quantity that would suffice.  If the idea gets up, then we can look at custom made sensors to get the price down.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\20@203235 by Xiaofan Chen

face picon face
On Tue, Feb 21, 2012 at 9:09 AM, David Duffy (AVD)
<davidEraseMEspam.....audiovisualdevices.com.au> wrote:
> I might revisit the PIR modules.  Finding something sturdy enough as an
> off the shelf product is the ideal scenario.  We *could* build sensors,
> but I'd rather not just yet as it's just an idea with no commitment to
> bulk quantity yet.  If I could buy a ready to go sensor with a cable
> tail for under $50 in small quantity that would suffice.  If the idea
> gets up, then we can look at custom made sensors to get the price down.

Maybe you can try to look at some photoelectric sensors -- look
for "Diffuse Mode" sensors. Sensing range of 1000mm is not a
problem. The mutual interference part can be a problem but your
requirement may not require such a feature as the distance between
the sensors are sufficiently apart.

For example, you can search here, not so sure about the "US$50 in small
quantity part" as I no longer follow the product closely.
www.pepperl-fuchs.us/usa/en/classid_47.htm
Disclaim: I used to work for Pepperl+Fuchs until 2006.

Other vendors include Banner Engineering, SICK, Omron, SUNX, etc.

-- Xiaofan

2012\02\20@204403 by Marcel Duchamp

picon face
On 2/20/2012 5:09 PM, David Duffy (AVD) wrote:
> red, and particular lens patterns are used for particular targets
> Hi Joe,
> I might revisit the PIR modules.  Finding something sturdy enough as an
> off the shelf product is the ideal scenario.  We *could* build sensors,
> but I'd rather not just yet as it's just an idea with no commitment to
> bulk quantity yet.  If I could buy a ready to go sensor with a cable
> tail for under $50 in small quantity that would suffice.  If the idea
> gets up, then we can look at custom made sensors to get the price down.
> David...
>

Zilog makes a cheap one supposedly good to 5 meters: 269-2513-ND for about $6.00
If it senses too broad, you can shutter it a bit to narrow the view.  Think "barn doors" on photo lighting equipment.

Sparkfun has some also

2012\02\20@204619 by IVP

face picon face
> I might revisit the PIR modules

You could try one (security sensors, especially exterior, are often
at giveaway prices, w/o bulbs) and window the lens with paint or
paper to limit its view

2012\02\21@002152 by David Duffy (AVD)

flavicon
face
On 21/02/2012 11:46 AM, IVP wrote:
>> I might revisit the PIR modules
> You could try one (security sensors, especially exterior, are often
> at giveaway prices, w/o bulbs) and window the lens with paint or
> paper to limit its view

Panasonic have some small PIR modules starting around the $15 mark that might do if can reduce the range.

I tried an ultrasonic ranging module (SRF02) today and it works quite well.   That may be a solution if ceiling mounting them becomes an option as they should be away from abuse and dust up there.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\21@005754 by IVP

face picon face
> ceiling mounting

The shop up the road has a PIR pointing down from the ceiling
in the doorway. Seems very selective, the sweet spot is about a
square metr

2012\02\21@013155 by YES NOPE9

flavicon
face
Possibly the Doppler radar can be restricted to a shorter range by attenuating the signal.
Perhaps a wire mesh in front of the unit.
There is also a pot that claims to adjust the range.....
gus

{Quote hidden}

>

2012\02\21@061313 by Nily

flavicon
face
Ok, if you have enough light to see the targets, you can always detect them
using low cost cameras. By the way, you can use to detect and log ( if the
latter is needed).

Rodolfo

-----Mensaje original-----
De: EraseMEpiclist-bouncesspamspamspamBeGonemit.edu [RemoveMEpiclist-bouncesKILLspamspammit.edu]En nombre de
David Duffy (AVD)
Enviado el: Monday, February 20, 2012 5:04 PM
Para: Microcontroller discussion list - Public.
Asunto: Re: [EE] Proximity Sensors


Thanks for the link.  I checked them out but they have a min range of 3
metres, which will cause triggering by people way outside the target range.
David...

On 21/02/2012 9:42 AM, Nily wrote:
> David
>
>
www.suntekstore.com/goods-14001970-Wireless+Module+Doppler+Radar+Micr
{Quote hidden}

--
___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\21@080323 by Bob Ammerman

flavicon
face

----- Original Message ----- From: "David Duffy (AVD)" <@spam@david@spam@spamspam_OUTaudiovisualdevices.com.au>
To: "PicList" <spamBeGonepiclistspamKILLspammit.edu>
Sent: Monday, February 20, 2012 5:42 PM
Subject: [EE] Proximity Sensors


> Has anyone here done much work with proximity sensors?  I am looking to
> trigger an event when someone stands in front of (or walks past) a
> specific area in a retail environment.  The sensing must be done from
> one side only (no beam break methods).

Ultrasonics polled in order so they don't interfere with each other?

-- Bob Ammerman
RAm Systems

2012\02\21@102652 by RussellMc

face picon face
> Ok, if you have enough light to see the targets, you can always detect
> them
> using low cost cameras. By the way, you can use to detect and log ( if the
> latter is needed).

I read down looking for the camera suggestion and was surprised to not
see it - but Rodolfo saved the day.

Canon A series camera until recently could be controlled using
software loaded on the SD card and written using the flexible powerful
and free
CHDK aka Canon Hack Development Kit.
http://chdk.wikia.com/wiki/CHDK

Every known and available feature of the cameras can be controlled
plus you can get them to do things outside their apparent specs.
You can write programs for the camera to run or set up various
boundary conditions including detecting movement within a predefined
area. The camera could deliver an image or just a trigge

Various builds and supported models
http://mighty-hoernsche.de/

Features
http://chdk.wikia.com/wiki/Features

NB:
  Motion detection - Trigger exposure in response to motion, fast
enough to catch lightning

Scripting - Control CHDK and camera features using ubasic and Lua
scripts. Enables time lapse, motion detection, advanced bracketing,
and much more. Many user-written scripts are available on the forum
and wiki.

USB remote - Simple DIY remote allows you to trigger exposures or scripts.

Manual:
http://chdk.wikia.com/wiki/CHDK_User_Manual

More

 Russell McMaho

2012\02\21@145442 by YES NOPE9

flavicon
face
Using low cost cameras  ==>  good call by Russell

you can also use RaspberryPi or Guruplug to control low cost USB cameras.
Both are running linux and are cheap.
OpenCV is a great Linux FLOSS package for smart cameras.
gu

2012\02\21@151116 by Robert Rolf

picon face
May I suggest you use COTS PIR sensors from the alarm industry? They are
small, cheap, modular,
and readily available. Many can be set to close a contact immediately on
motion, or after 2 or 3
'beams' have been passed by. 12V at 50 mA for power makes them easier to
use than most
'security light' types.

Many have 'range' pots so you can dial down their sensitivity, and by
aiming them correctly,
at the floor at 3' distance, you prevent false triggers from targets
farther away than you desire.

Many also come with interchangable lenses with differing numbers of focal
elements, giving you more
or fewer detection beams. You can mask out the beam pattern with opaque
paint to get exactly
the sensing box you desire.

Given their range, you could mount them on the ceiling in a store, to get
them out of harms way,
while giving you exactly the trigger box you desire.

They also have the advantage of KISS, where a contact closure triggers your
playback/ animation,
so no fancy controller required.

Rober

2012\02\29@063015 by David Duffy (AVD)

flavicon
face
part 1 1281 bytes content-type:text/plain; charset="gb2312" (decoded base64)

After some discussion on another list (forum), the idea of using vehicle
parking sensors came up. This seems ideal as the sensors are quite
cheap, already sealed and designed for simple through panel installation.

The basic idea seems to be to send out a 40KHz ring pulse and time it's
return. Has anyone ever interfaced these off-the-shelf sensors to a PIC?
David...

On 21/02/2012 8:42 AM, David Duffy (AVD) wrote:
> Has anyone here done much work with proximity sensors?  I am looking to
> trigger an event when someone stands in front of (or walks past) a
> specific area in a retail environment.  The sensing must be done from
> one side only (no beam break methods).
>
> The sensing range would need to be approx 200mm - 1000mm (8" - 40").  
> The horizontal detection width would need to be approx 500mm (20") at
> end of the range I guess.  There would be multiple sensors, spaced at
> approx 600mm - 900mm (24" - 36") intervals.
>

--
___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________


part 2 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
mailman.mit.edu/mailman/listinfo/piclist

2012\02\29@064538 by IVP

face picon face
part 1 156 bytes content-type:text/plain; charset="gb2312" (decoded base64)

> Has anyone ever interfaced these off-the-shelf
> sensors to a PIC?

Popular in robotics. Google ultrasonic robot

part 2 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
mailman.mit.edu/mailman/listinfo/piclist

2012\02\29@065239 by David Duffy (AVD)

flavicon
face
On 29/02/2012 9:45 PM, IVP wrote:
>> Has anyone ever interfaced these off-the-shelf
>> sensors to a PIC?
>
> Popular in robotics. Google ultrasonic robot

Yeah, already played with the robot ones.  They are open transducers.  The sealed ones need a lot more drive level it seems.

I guess my question is really two-fold;

A) Does anyone have a reasonable reference design for interfacing to the sealed parking type sensors?

B) Is there some basic code out there that shows what's required the ping and receive?

There are lots of Google hits for unsealed Tx-Rx pair system, but not much for the sealed all in one units.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\29@070315 by alan.b.pearce

face picon face
> Yeah, already played with the robot ones.  They are open transducers.
> The sealed ones need a lot more drive level it seems.
>
> I guess my question is really two-fold;
>
> A) Does anyone have a reasonable reference design for interfacing to the sealed
> parking type sensors?
>
> B) Is there some basic code out there that shows what's required the ping and
> receive?
>
> There are lots of Google hits for unsealed Tx-Rx pair system, but not much for the
> sealed all in one units.
> David...

Sounds like time to mount the 'scope in the car, and do some manoeuvring ....


-- Scanned by iCritical.

2012\02\29@071033 by Isaac Marino Bavaresco

flavicon
face
part 1 2050 bytes content-type:text/plain; charset="gb2312" (decoded base64)

I bought one China-made parking sensor with 4 transducers to reverse
engineer.
Very interesting design.

Uses a Cypress 8051-based PSOC with some programmable analog building
blocks.
I drawn parts of its schematic, I can send it if you are interested.
It uses canned trimmable transformers, similar to radio IF transformers,
but with just two two-pin windings.

The analog functions of the PSOC seems to be used for filtering.

It uses one CMOS analog multiplexer to scan the transducers. There is
just one analog front-end


What I liked most in that device is that the same transducer sends and
receives the pulses, and they are waterproof.
It cost USD25.00 and comes with four transducers. It is cheaper than
buying just the transducers from Digikey.


Best regards,

Isaac



Em 29/2/2012 08:30, David Duffy (AVD) escreveu:
> After some discussion on another list (forum), the idea of using vehicle
> parking sensors came up. This seems ideal as the sensors are quite
> cheap, already sealed and designed for simple through panel installation.
>
> The basic idea seems to be to send out a 40KHz ring pulse and time it's
> return. Has anyone ever interfaced these off-the-shelf sensors to a PIC?
> David...
>
> On 21/02/2012 8:42 AM, David Duffy (AVD) wrote:
>> Has anyone here done much work with proximity sensors?  I am looking to
>> trigger an event when someone stands in front of (or walks past) a
>> specific area in a retail environment.  The sensing must be done from
>> one side only (no beam break methods).
>>
>> The sensing range would need to be approx 200mm - 1000mm (8" - 40").  
>> The horizontal detection width would need to be approx 500mm (20") at
>> end of the range I guess.  There would be multiple sensors, spaced at
>> approx 600mm - 900mm (24" - 36") intervals.
>>
>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - http://www.avg.com
> Version: 10.0.1424 / Virus Database: 2113/4837 - Release Date: 02/28/12


part 2 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
mailman.mit.edu/mailman/listinfo/piclist

2012\02\29@071146 by David Duffy (AVD)

flavicon
face
On 29/02/2012 10:03 PM, .....alan.b.pearcespam_OUTspamstfc.ac.uk wrote:
>> Yeah, already played with the robot ones.  They are open transducers.
>> The sealed ones need a lot more drive level it seems.
>>
>> I guess my question is really two-fold;
>>
>> A) Does anyone have a reasonable reference design for interfacing to the sealed
>> parking type sensors?
>>
>> B) Is there some basic code out there that shows what's required the ping and
>> receive?
>>
>> There are lots of Google hits for unsealed Tx-Rx pair system, but not much for the
>> sealed all in one units.
>> David...
> Sounds like time to mount the 'scope in the car, and do some manoeuvring ....

I have an after market 4 sensor system on the way.  :-)

Hopefully, being cheap they don't use any esoteric parts.

The PIC code should be easy enough now that I've found a bit more info on their general operation.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\29@071309 by Isaac Marino Bavaresco

flavicon
face
Em 29/2/2012 08:52, David Duffy (AVD) escreveu:
> On 29/02/2012 9:45 PM, IVP wrote:
>>> Has anyone ever interfaced these off-the-shelf
>>> sensors to a PIC?
>> Popular in robotics. Google ultrasonic robot
> Yeah, already played with the robot ones.  They are open transducers.  
> The sealed ones need a lot more drive level it seems.
>
> I guess my question is really two-fold;
>
> A) Does anyone have a reasonable reference design for interfacing to the
> sealed parking type sensors?
>
> B) Is there some basic code out there that shows what's required the
> ping and receive?
>
> There are lots of Google hits for unsealed Tx-Rx pair system, but not
> much for the sealed all in one units.
> David...


I measured several parameters of the one I bought from China (frequency,
pulse width, number of pulses, etc.). I can send the results if I can
find them...


Isaac

2012\02\29@071531 by David Duffy (AVD)

flavicon
face
On 29/02/2012 10:10 PM, Isaac Marino Bavaresco wrote:
> I bought one China-made parking sensor with 4 transducers to reverse
> engineer.
> Very interesting design.
>
> Uses a Cypress 8051-based PSOC with some programmable analog building
> blocks.
> I drawn parts of its schematic, I can send it if you are interested.
> It uses canned trimmable transformers, similar to radio IF transformers,
> but with just two two-pin windings.

I found one "hack" article and it showed the transformers you mention.  Not sure how available (in small qty - say 100) they are.

{Quote hidden}

Crazy isn't it!
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\29@071633 by David Duffy (AVD)

flavicon
face
On 29/02/2012 10:13 PM, Isaac Marino Bavaresco wrote:
> I measured several parameters of the one I bought from China (frequency,
> pulse width, number of pulses, etc.). I can send the results if I can
> find them...

That would be great Isaac.  Only if it's no bother though.
David...

-- ___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: http://www.audiovisualdevices.com.au
___________________________________________

2012\02\29@073419 by Isaac Marino Bavaresco

flavicon
face
Em 29/2/2012 09:16, David Duffy (AVD) escreveu:
> On 29/02/2012 10:13 PM, Isaac Marino Bavaresco wrote:
>> I measured several parameters of the one I bought from China (frequency,
>> pulse width, number of pulses, etc.). I can send the results if I can
>> find them...
> That would be great Isaac.  Only if it's no bother though.
> David...


No problem, it will be a pleasure.

What I want is to design my own system for R/C use but I don't have much
time for hobby now, so the project is dormant.
Besides, as I'm mostly a digital guy, I'm struggling with the filter
part. I can calculate and design active filters, but I'm not sure what
are the necessary parameters for them, and I don't have time to do much
experimentation.

Perhaps we could cooperate in the design.


Best regards,

Isaac

2012\02\29@124807 by Steve Smith

flavicon
face
I have just done a little module for those (SRC04) modules that operates a
servo from two set points and is designed for putting wheels away on rc
aircraft. Simple to use you need to do a little averaging to be sure of the
distance but its quits simple

Steve
{Original Message removed}


'[EE] Proximity Sensors'
2012\03\01@053814 by Electron
flavicon
face
At 13.03 2012.02.29, you wrote:
>> Yeah, already played with the robot ones.  They are open transducers.
>> The sealed ones need a lot more drive level it seems.
>>
>> I guess my question is really two-fold;
>>
>> A) Does anyone have a reasonable reference design for interfacing to
>the sealed
>> parking type sensors?
>>
>> B) Is there some basic code out there that shows what's required the ping and
>> receive?
>>
>> There are lots of Google hits for unsealed Tx-Rx pair system, but
>not much for the
>> sealed all in one units.
>> David...
>
>Sounds like time to mount the 'scope in the car, and do some manoeuvring ....

Nothing specific to You:

The wife does the manoeuvring, and the husband uses the oscilloscope.

or

The husband does the manoeuvring, and the wife uses the oscilloscope.

What will work best? *g*

More... (looser matching)
- Last day of these posts
- In 2012 , 2013 only
- Today
- New search...