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Home security system: SMS alerts, https event log, bluetooth passcode (dis)arming

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Recently, someone broke into our house while nobody was home during the weekend - They didn't disturb or steal anything, just probably getting financial info.


I have been brainstorming, gathering ideas that have been lying dormant. Here is what I have come up with so far:


System contains 8 - 20 wireless *(1) nodes with sensors.

System has one basestation, contains registration info for all nodes, contains bluetooth module for keyless arm/disarm of zones. *(2)


Each node will poll its sensor *(3) several times a second, and check in with the base station once an hour to inform that all is well. Any false result of polling the sensor will result in immediate warning sent to base station once per second for the duration of the false result. The base station will then upload to the server in the cloud the event ID (i.e. which door/window of the house), duration, and time of event. The server will then send out a text message (at the beginning of the duration to ensure prompt alert) to the person responsible for said door/window (this is useful if there are multiple people in the same house, and each bedroom's sensors will alert the occupant).


*(1): I have purchased several wireless modules which I plan to remove the internal circuitry and replace with MSP430's, possibly keeping the radio. They also have 90db speakers installed, which could be used to transmit data ultrasonically (no pets in the building).

*(2): Bluetooth pairing beforehand, not visible to unpaired devices. Requires app on phone to log in and send code for (en/dis)able of zone. Zone may include multiple devices, i.e., the whole house excluding specific rooms.

*(3): Whether infrared or magnetic leaves, but I prefer IR.


I also want the server to be accessed externally via web interface (HTTPS - login required) so that the events can be reviewed. I currently have a Linux webserver already running one Wordpress site, so it wouldn't be a problem adding another website or sub address.


Any suggestions/additions? Are there any projects already incorporating elements described here that I can reference code?

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I actually did something similar, in a very amateurish manner, and only one simple door open/close sensor:




As you can see this thing is going to be noticed by any intruders, so the goal was to send alert out of the scene asap. Back then a full PC is needed (used Wiring program running to listen for the signal from the 2231 through COM port). Now the CC3200 series should ease things a lot. You already have a server in the Internet, but nevertheless may i recommend amazon aws which offers a free one-year free-tier, running linux or windows 24x7 for free for a year. For SMS I use Nexmo which is so far reliable on my local carrier. I'd definitely suggest video / photos triggers, as they are very useful evidence should bad things happens (again, send images out of the scene, so that intruders cannot destroy them). The base station, whatever it is, should be secure for otherwise the bad guys could take that away and figure out later the other end which is the server in the Internet.


By the way, I'd suggest you to contact the local law enforcement and also your banks if you have not yet done so. The bad guys may be planning something, or have already in possession of credit card numbers from reading bank statements. Take care.

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Would it make sense to have the base station try to detect interference/jamming attempts?

(e.g. track broadcast power in whatever RF band you are using, track partial/incomplete messages, etc.

Possibly alert on some conditions.)


If the IOT thing takes off, with more and more devices chattering all the time seems like interference may be increasing problem.

Also, for an alarm system, how do you protect against denial of service attacks.


Bluetooth - require a longish PIN (to reduce risk of pairing attacks).

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I have a project that is somewhat similar http://www.forum.43oh.com/index.php?/topic/6003-imp%2Eguru-Droplet-and-915MHz-Long-Range-Radio-to-WiFi


I use it to monitor temp but the next version will be adapted to also have a accelerometer to detect disturbances.


Electric imp is a easy way to connect these sorts of things to the cloud IMO.


Bluetooth makes it all more complicated...

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@@nuetron - sorry to hear that - hopefully they just got spooked by a neighbor or something.


I'm actually working on something myself.  I haven't worked on it lately, but I've got some wireless sensor designs that I've worked out and am in the process of programming.  I wanted a server-side system which also required a wifi gateway like the CC3200.  Haven't been able to port the NRF24L01 library to CC3200 yet so I kind of stalled.  You can take a look at some of the parts I purchased in my thread - http://forum.43oh.com/topic/5851-wireless-security-system-iot/ 

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Oh - and on the security end of things - I honestly wouldn't bother working on it too much.  If someone cares enough about breaking into your home to hack your DIY security system - they'll get in.

There is an AES encryption library for the 430 though if you're interested in security - although you'd need to consider replay issues.  

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Thanks all! I had a long response all typed out and addressed to people, but had a glitch and tapatalk lost it.


One of the things I had hinted at was using the sensor modules' built-in speakers for ultrasonic communication, instead of the typical RF communication, that would be so out of band as to be alien to the normal hacking.

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Thanks all! I had a long response all typed out and addressed to people, but had a glitch and tapatalk lost it.


One of the things I had hinted at was using the sensor modules' built-in speakers for ultrasonic communication, instead of the typical RF communication, that would be so out of band as to be alien to the normal hacking.

That has happened to me a few times with tapatalk, nothing more frustrating...


My advice on the ultrasound: is the goal of your project to create a ultra sound communication system or a home security system? Both require a lot of work, I would encourage you to use a off the shelf radio first because it is low risk, then after you have the radios working, see if you can make Ultra sound comms happen.


I've found this to be something that I was struggling with in my projects, I would brainstorm so hard to figure out ways to make them novel that I was never able to get them off the ground due to the effort and invention required. Now I try to go for something more like a Minimum Viable Project.

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I'm kinda creeped out by where I moved to as well and was going to do the same thing.

I'd use PIR modules and ultra sound modules and have a few different nodes across my house using the NRF 2.4ghz modules. Wireless receive is expensive in terms of RF & current. I'd have a powered hub thats always in receive and have sensors that transmit every 1 - 10 seconds. This method amounts to uA of current usage average for the radio. If ~2x messages are lost or a breach message is sent, have the alarm trip. Sensors would be battery powered and need a recharge every 1-2 months. Would use a lithium + usb charging system. Disarming would require a keyfob type of rfid tag that you could wear. After a trip event your sensor could listen for the fob or if your message reaches the hub, it could ignore all breach messages. Fob would likewise transmit every 1 - 10 seconds and since that doesn't have a sensor attached to it, it could last for years on a single charge.


Then perhaps the easiest way to have the web enabled would be use a ras pi or beagle bone server. On the hub you would want a full wavelength antenna such that it can pick up all the sensors in your house.

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Has anyone seen this or hacked this for home security: http://www.amazon.com/gp/product/B00DH2VOXK

At $12 (+$9 for more sensors) it is a throwaway price. Initially was priced at $200 and sold thru Radioshack.

The product build hardware quality is quite nice. The reason for low price tag seems to be that manufacturer went belly up and they are getting rid of stock.


While the hardware is good and works just like any other home security system, its configuration is done almost entirely over SMS messages - which is a pain (which may be the reason why it was a failure.)


If I had to source the components/sensors myself I bet it would cost me more than $20 shipped.


I plan to use it as a secondary or fail-over burglar alarm because I already have another system installed and I prefer to have central monitoring. This is so cheap I can have door-open sensors on every cabinet door :smile:

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Well, the sensors arrived. I haven't double-checked the online listing, but it looks like the "Wireless" aspect was only that they do not require a wired power supply.

The internal circuitry consists of a button cell battery pack, inductor, unprotected reed switch (no glass casing), Piezo, and plastic-blob-covered integrated circuit (dislike those...). The way these work is on a current status basis. The door opens, the alarm sounds, the door closes, the alarm quits.


I have purchased a set of the system that CJN mentioned above, so I will see how that goes. Until that comes in and for quite a while afterward, I will be busy with the bluetooth module that came in yesterday (HC06 type). Time to learn Bluetooth and developing android apps (I have been wanting to for some time anyway, just never had the hardware for it). Anybody ported mspgcc to android yet?

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Bet there's a serial port in it somewhere.

But it comes with a 25 dollar tmobile sim, so why bother? (aside from the because I can aspect)


There seem to be three or four leads and may be programmable in someway.


Seems like these are made by same OEM (priced at ~$200):



For 12$ a piece they are paying you back $25 in T-mobile pre-paid cash i.e they are paying you $13 to order this.  :smile:


In other research on this item, looks like it had an iPhone app, but removed from iTunes store:


Android app seems to be still available:



I am hoping is if this could be interfaced to a home server (raspberry-pi) to receive event notifications and to send control signals, it opens up to a lot of possibilities. Like SmartThings but for a fraction of the cost (and SmartThings does not have GSM or backup batteries!)


Functionality I am currently missing from my home security system (which it is capable of doing but does not do):

1. Turn on automatically when there is no motion on some PIR sensors or at certain times of the day.

2. Log every event

3. trigger to Linux "motion" security camera recording server.

4. chime when mail-box is opened by postman.

5. chime when motion is detected on front porch or near front door (so that UPS/FedEx guys don't have to ring the bell, and scare package thieves )

6. turn on some lights when motion is detected at night.

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