Microprocessor for alarm system
Myauk
I am going to design an alarm system including smoke, gas alarm and
buzzer.
I am asked to use the microprocessor for it.
Using a microprocessor, I think I can add more features to the alarm
system yet I do not know what are the availble features of such
systems.
Can anybody suggest the suitable microprocessor for it?I don't want to
use the old intel 8085 for it.
Regards
JeffM
>Can anybody suggest the suitable microprocessor
Myauk
> Myauk wrote:
> >Can anybody suggest the suitable microprocessor
>
I am now reading the notes from wikipedia.
But still I need some suggestion from practical people
Regards
David L. Jones
First of all, why bother?
There are plenty of fully built and fully debugged alarm systems on
the market, they can be configured to do anything you want.
The last thing you want with an alarm system is for it to be
unreliable in either hardware or software. Someone else has already
spent years debugging the hardware and firmware to make them reliable.
You'll be starting from scratch.
That might be fine for just an intruder alarm, but when you start
talking smoke and gas sensors, you are talking about people's lives
here, so don't muck around and try to do it yourself.
But if you *really* want to do it, practically any 8bit micro will do
the job, it's just I/O, nothing fancy required on the micro side. All
the input protection/windowing and output drivers are all still done
in discrete hardware.
Or is this an assignment?
Dave.
JeffM
>>http://www.google.com/search?q=cache:J4NMFTEexmkJ:en.wikipedia.org/wiki/List_of_common_microcontrollers+8051+AVR+MSP430+PIC
Myauk wrote:
>I am now reading the notes from wikipedia.
>But still I need some suggestion from practical people
Apparently you skipped the first day of class
or your instructor jumped over the first chapter:
http://groups.google.com/group/sci.electronics.design/msg/6a338940c700dad2?q=*-*-*-begin+*-*-*-*-*-specification.writing+put.numbers.on.as.many.things.as.possible+Limitations+rather.*+spells.out+get-the-spec-right+*-*-*-*-*-Hz
http://www.google.com/search?q=intitle:Specification.Writing+include+OR+includes+dimensions+tolerance+OR+tolerances+-dimension+-0471618928
Eeyore
Myauk wrote:
You need a *microcontroller*.
If you're familiar with Intel products, check out the 8051 family and its
varaints from many many vendors.
Graham
Eeyore
Myauk wrote:
How much more work do you expect to get done for free ?
You need to start by writing (or just thinking through) a system specification.
Graham
mpm
> Hello,
> I am going to design an alarm system including smoke, gas alarm and
Many residential / commercial burglar & fire alarms have the following
general characteristics:
1 - Output relays (usually several, and each is programmable by
event)
2 - A secure communications protocol to contact the authorities
(monitoring station)
3 - A secure communication bus to "talk" to user keypads
(alphanumeric, numeric-only, even key switches, etc...)
4 - Support for multi-zone operation. (Some areas can be secured,
while others remain off. etc..)
5 - Power limited circuits for fire protection devices
6 - Integrated siren driver circuits, perhaps with different sounds
for different types of alarms.
7 - Automatic low-battery cut-off circuits (to avoid damaging backup
battery during prolonged outages)
8 - Switched power supply (to reset certain commercial smoke
detectors)
9 - Wireless sensor compatability, though this is usually done as an
add-on.
10 - A "Panic" feature (duress) which makes the panel behave as if
it's been deactivated correctly, when in fact it is calling the
police.
11 - Various door access controls (using same keypad as arm/disarm),
but can be used when the alarm panel is not secured (armed). For
example, to open a gate or door.
12 - A "chime" function, to announce arrivals when the system is
disarmed.
13 - An alarm printer port (for hard copy printout)
14 - Various "zone extenders", to minimize wiring in larger
installations.
15 - Output controls to operate video recorders (during an alarm
event).
This should get you started.
Oh, I fogot an important one: Support for both slow and fast loop
response.
Some sensors work better when they are looked at slowly over time,
whereas others can be so quick (like piezoelectric), that you need to
"stretch" their pulse out to a reasonable length in order for the
panel to "see" them correctly. This stretching is often done in the
alarm panel, though it can also be accomplished with external
circuitry.
Many alarms were built around the Z-80 (8085), though you will
probably find a lot of circuits using 8051's and derivatives.
-mpm
Jan Panteltje
<aungko...@gmail.com> wrote in
<1182906141.5...@c77g2000hse.googlegroups.com>:
Use some PIC.
NO I WILL NOT WRITE EXAMPLE CDE.
LOL
delo
http://www.mediagab.it/hardware/didattica/antifurto/antifurto.html
it's in italian language...
bye
delo
"Myauk" <aungko...@gmail.com> ha scritto nel messaggio
news:1182906141.5...@c77g2000hse.googlegroups.com...
Nico Coesel
These days ARM7TDMI based microcontrollers are easy to get your hands
on. They work very fast and are quite cheap.
--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
Joe G (Home)
If this is your first project you should
"BEGIN WITH THE END GOAL IN MIND"
Define exactly what you want to do
- how many sensors,
- what type od sensors
- how are they connected
- what voltage and power is required
- how will they signal back to the main unit?
- how will you turn the alarm on / off..
Basically look at other alarm specifications to make your own.
Once you have this info.... you can start breaking down the design in to
little bits... and work on one at a time.
Joe
"Myauk" <aungko...@gmail.com> wrote in message
news:1182906141.5...@c77g2000hse.googlegroups.com...
Myauk
Regards