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Micro-controller application in domestic alarm systems

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maxster03

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Design and construction of an home alarm system. It should be a stand-alone microcontroller based. Audible or visible alarms will be used initially for indicating potential break-ins, and system should be highly "intelligent" to differentiate genuine intruders as opposed to friendly pets. Use of web camera(s) are to be investigated for remote monitoring, maybe using the mobile phone with video capture facilities. Addi tonal features such as a text message delivered to the owner of the house if someone breaks into his house and others included.

i am thinking of using two IR sensors, placed in different heights so if the PIC16F877A gets signal from the top and bottom sensors that means its an intruder and if it gets signal from only the bottom sensor it would mean its a pet animal.

if someone else have any ideas. or additional feature i can add

please let me know.


thanks for your time and help

max
 

rezer

New Member
The IR sensors will be wired to your controller with a zone monitoring input, correct? I would suggest pointing the IR detector towards the point of entry like a door or window. Another thought, instead of using your low-level PIR for pet detection, just use the high-PIR for intruder detection (Unless your concerned about low crawlers.:D). You can mask off sections of the field of view of the PIR to focus specifically on door ways or other areas of the room.

You might consider using reed switches to monitor the doors and windows. This would typically be done with a resistor in parallel with the switch at the end of the line(EOL), screwed across the switch terminals to monitor the normal condition (what ever the resistor value is). When someone breaks in the switch shorts the resistor and the controller senses the alarm condition.
This would also allow you to use your PIRs in a logic AND fashion, it that the PIR trip will be accepted only if another zone is tripped. It will also increase your coverage, since the doors and windows would be monitored, the PIR could monitor the center of the room.

Glass break detectors are another option. These can sense different types of glass breakage, such as normal pane glass or tempered glass. These should also filter out pet noise, such as a dogs chain when it scampers across the floor.

Also, you might consider using smoke detectors, either silent or with a piezo.
You can use a silent smoke if you use an alarm bell. The bell can be used for both burg and fire. If you go with a silent smoke, make sure they can be monitored by your controller (i.e. you can strap an EOL resistor across it).

Will this report to a central station or just be a local alarm? You could use networking to communicate as well. It just depends on how advanced you want to make it.

Flashing lights are a good idea. They draw attention.

You might also want to use relay/open-collector outputs to drive lighting or other things.

There are also mfg who build wireless zone monitoring equipment. This save on the install.

You will want a backup battery in case of loss of AC.
 

maxster03

New Member
well thank you so much for your reply

oh i think i forgot to mention that above project is for my final year university project so i also have to take care of the money and time issues as well

P.S: i have thought of having on sensor instead of two but i don't know, i feel i should have two. i don't know why :rolleyes:
 

rezer

New Member
well thank you so much for your reply

oh i think i forgot to mention that above project is for my final year university project so i also have to take care of the money and time issues as well

P.S: i have thought of having on sensor instead of two but i don't know, i feel i should have two. i don't know why :rolleyes:
The number of sensors you need depends on what you want to cover. If it's just for demonstation purposes, one is fine, but not practical in a real world app. Weight this in your decision.

Another idea:
What you might want to do is make an architectual drawing of a home or business with all the rooms and have different devices simulating tripped alarms. You can use LEDs as annuciators to signal an alarm state and switches to do the actual tripping. Use a buzzer for the bell. This would be fairly simple.
 

Mercur

New Member
Your two sensors one high and one low, how large is their field of veiw and say for example you had a large dog that dcided to stand on its hind legs against the door triggering the upper level IR sensor?
 

maxster03

New Member
well it would be at waist height, as it is a university level project so i think some assumptions can be made which would include big doggies :rolleyes:
 

Mercur

New Member
Just checking it is something that might easily be overlooked.
 
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