Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 02:16am 09 Mar 2018
Copy link to clipboard
Print this post
Following our attempted break-in a few weeks back I've been updating our security.
Have an 8 channel Security Panel with just 2 heads at present, (had it for years). Bit of a pain to partially arm all the time & outdoor sensors are still prone to false alerts, wandering cats visiting etc.
Security NVR has 12 cameras & can trip alarms on motion, intrusion & line crossing events, but pretty had to avoid false alerts.
Also added a couple of Alert PIR's out the back, Ahla driveway monitor, but animals can trigger them.
BUT, False alerts are going to drive us crazy. Already had four trips out of ben in the early hours in the past 2 weeks.
So I was thinking I should setup some sort of additional device on an MM.
Something like an old wallet easily found stuck in the side of a chair etc. Old mobile phone, not too hard to discover...
Any suggestions on what sort of devices would be best to trigger on if it's removed.
Though of an NFC tag first up, but not sure that would suit. Reed switch & magnet sound a bit hard to manage.
Doesn't matter what I need to hide in the wallet, (or handbag), as long as it's relatively discrete & gives a very positive removal indication.
Thanks
Phil.Edited by Phil23 2018-03-10
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 07:33am 09 Mar 2018
Copy link to clipboard
Print this post
HI Phil,
Just an idea - use a battery-powered 28pinner and put the MM to sleep (CPU SLEEP) to minimise current draw. House this in a small 'disguised' box. Then connect a reed-switch to the WAKEUP pin. Now whenever a magnet is moved to/from then reed-switch the MM will near instantly wake up and can do something! To keep the above circuit as battery powered circuit, put an IR Tx on it and transmit an IR 'trigger' signal to another mains powered MM. This can then fire off something more 'power-hungry' such as a siren/flood-light.
So attach a magnet to whatever 'target device' you end up using, and place it on the disguised 'self-contained' small battery-powered MM circuit .
One of BigMik's NanoMites/PicoMites could be good for this (although it is also easy to build on a small bit of Vero-board if SMDs are not you're favourite)!
WW
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 09:20am 09 Mar 2018
Copy link to clipboard
Print this post
Power is probably not an issue, more the detection means.
Thought about a reed switch, but in the case of the wallet left carelessly on the chair, a reed switch would be a bit too precise.
Copper or Al-foil in the wallet? Can I some how detect that with resonance or something. As in the thing needs to move 6 inches to a foot before it's absents is detected.
Realistically, what's on the sending side can be either hard wired, or hanging off something like a 7Ah battery for example.
Phil.
CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2171
Posted: 09:23am 09 Mar 2018
Copy link to clipboard
Print this post
Grogs might be able to cut you a deal on a load of ball bearing trembler switches
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 09:43am 09 Mar 2018
Copy link to clipboard
Print this post
Could you not use an under-carpet (or rug!) pressure mat?
Position an object (i.e. the bait) where-ever you can guarantee someone will tread - then position the pressure-mat under a rug. The rug will 'highlight' to you where not to tread.
That way, no special sensing set-up or alignment is required
Not exactly detecting 'removal', but guess this could be the kind of thing you're after? Edited by WhiteWizzard 2018-03-10
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 10:06am 09 Mar 2018
Copy link to clipboard
Print this post
Gotta be something imune to our every day life.
Pressure mat would require training a teenager not to stand on it.
Like to know more about NFC tags & how they work.
Easy enough to wave one near a sensor to open a door, but if they are in the presence of the detector all the time can you figure they have at some point gone away.
Could a reader?? poll then every few seconds for presence? If so what range?
Phil.
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 10:33am 09 Mar 2018
Copy link to clipboard
Print this post
Hi again,
Yes NFC would be fine.
I have a one-wire RFID reader here on my desk connected to a 28pin BackPackv2. This reader can work easily with the MM by using the one-wire protocol built into MMBASIC.
The detection of lack of presence is very easy to accomplish - however, note that the circuit will pull slightly more current when a tag is within range - not a problem though for you by the sound of it.
If you use a 13.56MHz version of the reader then it has an added bonus. IF you place an RF bank-card (in the 'target' wallet) then this behaves as the NFC tag!
I will post a picture of the reader in a little while!
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 10:40am 09 Mar 2018
Copy link to clipboard
Print this post
The One-Wire RFID reader as mentioned in my previous post. I have not added these to the website ye; however, I do have both 125KHz and 13.56MHz versions immediately available.
Will post a code snippet next to show ease of use
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 10:49am 09 Mar 2018
Copy link to clipboard
Print this post
One-Wire RFID Reader sample code:
DO ONEWIRE WRITE 26,1,1,&H33. 'RFID data-out pin connected to MM Pin26 IF MM.ONEWIRE THEN 'tag present ONEWIRE READ 26,0,8,a,b,c,d,e,f,g,h. 'Read 8-byte tag value (if you want to!)
ELSE 'tag removed 'error check (i.e. check 'absence' several times); then trigger alarm
ENDIF 'other stuff below - (add a small PAUSE if nothing else)
LOOP
Edited by WhiteWizzard 2018-03-10
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 08:23pm 09 Mar 2018
Copy link to clipboard
Print this post
That's looking like the sort of solution I'm after.
Had thought that either the foil or little white plastic capsules on products for security could be kept in the "bait".
Once everyone here is educated about it should be relatively fault free while bait stays in place.
Any idea of the range WW? up to two feet would be superb, next to no false triggers, but then it will only be an internal alarm to notify us anyway.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 09:37pm 09 Mar 2018
Copy link to clipboard
Print this post
A 12 Gauge!
Oh, wait, not what you meant.
Close enough though. Tie the wallet to a piece of string running round a couple of pulleys to reverse the force, tie it to the trigger and you are there. And the little parasites won't be for much longer.
You are going to need a large Diameter garden hose, broom and a shovel as well for this system. Get a couple of Drums of Chlorine as well. Destroys the DNA....errrr, removes stains off concrete.
Let me know if you have any " Leftovers" that won't fit in the bin if it's a bit full already. I have a tractor and 20 very remote acres you can use to dispose of any extra garbage. The fact it will be hundreds of KM from you will be a good thing as well. Bring a bag of lime. Dissolves the bones..... of Sundays roast leg of lamb.... and is good for the soil.
You need a road trip for a couple of days don't you?
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 10:40pm 09 Mar 2018
Copy link to clipboard
Print this post
NFC is typically just a few centimetres. This reader will read a bank-card's NFC chip at approx 2cm. So the 'bait wallet' needs to pretty much be sitting on the reader. This is just fine as the wallet won't be moving by itself so 2ft just not needed (to avoid false alarms).
Active RFID tags are needed for a 2ft range - or alternatively expensive passive technology. Is there any reason (other than false alarms) that you require a read range of 2ft?
WW
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2959
Posted: 10:51pm 09 Mar 2018
Copy link to clipboard
Print this post
Forgot to mention that the reader pictured above has a diameter of approx 35mm; and a max read range of 4cm
And low cost 13.56MHz NFC 'stickers' can be used on other 'bait' items - however, only one tag can be read at a time.
IF you were looking at 'tagging' several items and wanted to detect the removal of at least one (from an area); you will not be able to do this with just one reader like this.
Multiple 'tags', and the removal detection of any one item (from a reasonable size area) will require active technology.
Active reading at short distances is very tricky (but doable). Larger distances make it easy - I once designed an active system to show automatically what lorries were present on a 'site'; and to log date/time that they left site - a perfect scenario for the application of active RFID.
Edited by WhiteWizzard 2018-03-11
Paul_L Guru Joined: 03/03/2016 Location: United StatesPosts: 769
Posted: 10:53pm 09 Mar 2018
Copy link to clipboard
Print this post
Can't the NVR be set up to detect indoor motion or line crossing and provide an alarm?
Paul in NY
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 01:03am 10 Mar 2018
Copy link to clipboard
Print this post
No Strictly false alarms, so maybe 6" would be a good distance.
Family & visitors are likely to check it, but would be ok as long as placement is not too precise.
Multiple tags I would have expected to need multiple detectors for this purpose as you say.
Discarded mobile phone is the other probable bait.
Phil.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 04:45am 10 Mar 2018
Copy link to clipboard
Print this post
Don't be too sure!
Unless it's within the last couple of models, they probably won't look at it. If you know anyone works at a phone store, you may be able to get a current models expensive Dummy display piece they have in the stores.
Remember with the triggering, it will only happen when the system is armed which would be at night or when you were out so any movement at all with the things should be a valid not a false alarm.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 08:44pm 10 Mar 2018
Copy link to clipboard
Print this post
A bloody big dog might deter most people.Cheers, Tony.
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 09:08pm 10 Mar 2018
Copy link to clipboard
Print this post
NVR has Motion Detection, Line Crossing & Intrusion Detection.
All very hard to fine tune. Motion is the most basic, but way to prone to false alarms. Moths etc.
I am slowly fine tuning it, but it takes a fair bit.
Trying to reliably set line crossing on one entry point to do a notification by email.
I either get tonnes of false ones, or miss a few events. Not suitable for a real alarm at this stage.
Other problem with say a pet immune motion alarm is the arming & disarming regime.
After a while you get a bit complacent & it's left unarmed when needed.
A couple of "Bait" alarms would be precisely the opposite. We'd tend to ignore their presence & they'd remain in a permanently manned state.
Phil.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 09:15pm 10 Mar 2018
Copy link to clipboard
Print this post
6 Moths ago I moved from one of the worst places in Oz as far as crime rates went. Been there over 20 years and as a beautiful home in once what was a very upmarket and well regarded area, it wasn't easy to leave my wifes family home that went back to her grandparents whom had bought it over 100 years ago.
We had not locked the back door in over 15 years. We were one of the very few places around we knew had not been done over despite others with fancy locks and back to base alarms that had.
We always had great big dogs that while Vicious and intimidating looking, were daily playmates of our young children and there was NEVER a moments concern with them. As the kids grew up, there was never any worry with them going anywhere around the place like to a friends or the corner shop when they were with the pups because the local low life would see the pups and literally run.
One shop owner would give the kids free sweets if they came back with the dogs because the trouble makers that hung around left when they showed up.
We are here in relative paradise where there has been known to be the not so odd break in because the area is all luxury acreages and targeted because people do have plenty worth stealing. We still don't lock the door and there no fences or gates.
The pup now is a bit smaller being a border Collie that's the biggest sook in the world but she knows her territory and it would still be a brave scumbag that tried to get in without us here. When we are, any visitor is likely to get the ball dropped at their feet and then be expected to throw as she lives to play fetch, endlessly, but the experience of a fried who dropped around to pick something up when were weren't here was pretty opposite and quite laughable in context.
You don't even have to get the sniveling beast, The over grown Rats that make a load of noise at the sound of the house creaking are just as effective because the last things these scumbags want is anyone knowing they are there when they are.
Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667
Posted: 09:20pm 10 Mar 2018
Copy link to clipboard
Print this post
Lol, Maybe.
Amazing what the Security Cameras get.
Few months back my son was home over Christmas, his dog in toe. Some time early AM a stray cat triggered the cameras, walked past the dog sleeping on a chair, sniffed him, then sprayed on the chair before having a bit more of a snoopa about.
Dog woke up about 1/2 hour later for a good sniff about....
Page 1 of 2
Print this page
The Back Shed's forum code is written, and hosted, in Australia.
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
Print this post
