search for an inexpensive device to detect housebreaking

[jedie]

I have some ideas around detecting housebreaking.

For example, a small device with WiFi and battery, which you glue to the windowpane. It should be able to detect when the glass breakes or when someone tries to break it. So it should be able to detect vibrations.

Because there are a few window panes, the whole thing together should cost quite little, of course.

So a few requirements:

• low cost
• Useable with AAA battery pack (I'd prefer normal Rechargeable batteries instead of a Lipoly battery)
• detect vibrations - maybe: Motion sensor (LIS3DH triple-axis accelerometer with tap detection, free-fall detection)
• LED for blinking (To see that's alive
• Gladly: Sound sensor (MEMS microphone)
• Only nice to have: Temperature/Light sensor

Seems the Circuit Playground Express https://www.adafruit.com/product/3333 fulfils all wishes, except that it is not cheap: $25 / 30€

Does anyone know a device that combines everything and is cheap?

[Dustfang]

How far apart are the windows? Any chance you could set up a vibration sensor package for each and run them all back to a single processing unit? I don't see any reason one controller couldn't track several sensors and log which was tripped.

[MostlyHarmless]

When someone is breaking the glass is ... hmmm ... IMHO too late. You want motion sensors that alert you when someone is on your porch. The automation would then turn on flood lights and whatnot and hopefully scare them away.

You also want motion triggered video recording with IR all over the place, streamed to some cloud storage.


Just some random thoughts, Jan

[kevinkk525]

And if you are very paranoid, you'd want to avoid using anything relying on wireless signals as those could be jammed, making your automations not triggering, except for those that run on the same controller.

[MostlyHarmless]

And if you are very paranoid, ...

I live in Pennsylvania. We are not paranoid. We are allowed to shoot the guy coming in through the window.

Yes, I do have those horrible things in my home. Quite a few actually. Fun to play with at the range too.

[pythoncoder]

Window break detectors are great fun. A place where I worked had them. Fortunately I wasn't the alarm keyholder. My boss was regularly hauled out of bed to reset the alarm when late night revellers set them off - presumably by rapping the window not hard enough to actually break the glass.

Doubtless in Pennsylvania he'd have been free to shoot them, but by the time he arrived they were long gone.

To get back on topic I suspect that the problem might be power consumption. To run on sensibly sized batteries for months requires current consumption measured in μA.

[chrismas9]

In days of old when Wi-Fi wasn't invented and nor were PIR detectors burglar alarms had reed switches on doors and mechanical vibration switches on windows. A vibration switch could wake up a device from sleep mode.

[MostlyHarmless]

Doubtless in Pennsylvania he'd have been free to shoot them, but by the time he arrived they were long gone.

In the home, sure. But going to the warehouse or factory at night to check on an alarm ... not so much. There are limits to the castle doctrine. Even here

To get back on topic I suspect that the problem might be power consumption. To run on sensibly sized batteries for months requires current consumption measured in μA.

Right.

Many years ago I got a set of these motion detectors.

The detectors themselves work for about one year on a 9V block. The base station has a wall wart and since it is flashing LEDs, I was able to just wire up a PIC18F to it to detect an alarm. So I basically added a USB interface to the base station. I think the sensors are just passive IR. Never figured out what they do over the air. Now I wonder if an ESP32 could actually communicate with them directly. However the point is that a PIR sensor can run for a year on a 9V block and periodically communicate wireless with a base station (the thing would notify on low battery). I think a vibration sensor should not have more demand for power, so an 8266 deep sleep design should be possible.


Regards, Jan

[jedie]

The requirement is not that the battery should last for months. A week or two would be fine.
Requirement is not having to build too much by yourself.

[MostlyHarmless]

Requirement is not having to build too much by yourself.

Define hobby.



My definition: "Hobby: An activity I like to do that consumes a lot of time an/or money and is allowed to temporarily/permanently occupy space, normally designated for other purposes (e.g. having a soldering station in the kitchen)."

I actually had a soldering station in the kitchen for several months when I assembled this:

TRX2A_1.jpg (169.08 KiB) Viewed 5008 times

It is a Yuma TRX2A short wave radio. The PCBs were delivered empty and all the SMD components had to be soldered on. Even the coils had to be wound by hand. Basically a 2000 pcs puzzle you have to solder together. The thing works an I am able to make contact with Europe from across the Atlantic on 10W transmitter power (using morse code on 10 or 20m band). My antenna isn't the best (not enough ground radials), so I yet have to succeed with real QRP on 5W.

I understand that morse code isn't the most popular form of long distance communication these days. It is just an example of what I consider a hobby.