Siren Project

Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
There are plenty of videos on youtube if you search for police siren. I quite like the French one. UK ones sweep up and down which is a touch more complicated to program but more fun.
I could be interested in helping out. I've got plenty of time on my hands at the moment.
http://www.youtube.com/watch?v=4fuOZ4bLn2k
OK mark U got the deal.
I donno whether u will touch my money or not but do PM me ur postal address. I always show gratitude towards those who have helped me.

What can you do actually?
What I want is a siren code for a PIC, This PIC will also be used to flash the LED's which I made before, and also it will monitor the siren battery charge rate. Which is a 12V 7A SLA.
I am familiar with PIC mikro MPLAB IDE.
I can modify any code written in this language.

I would go for a surface mount device if possible to make the circuitry smaller and a big headache for any one trying to steal my idea.

With tht battery I can get around 80W for an hour or so, This place is small so, police siren won't last even 30min. I have to boost the output to drive a 100W bull horn which I have checked around.

So for now these are the things I like to clarify.

On coming Saturday I will be meeting with Police staff in charge together with the contractor. I have to explain them the limitations and options available to the Cycle they had in mind.

I will show them options on the type of tone. Only they can finalize what type of tone they want.
 

Markd77

Joined Sep 7, 2009
2,806
I think that should handle it fine. I've got some 16F819s which seem pretty similar but I'm just about to make an order so I'll get an 16F88.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
To show them a prototype soon, I got to use what I have, getting components even through fedex takes weeks. even though fedex says 24 hr service.

I just like you to make a sample code for this PIC and sent it to me.
I can test it and verify.
I have to go step by step in these kinda things.
 

Audioguru

Joined Dec 20, 2007
11,249
20 of the world leaders have a meeting in my city now. The police bought 3 portable and one truck-mounted sound cannons to knock protestors off their feet with noises and messages. The portable ones produce 135dB and the big one produces 143dB.
Health officials say that sound levels above only 85dB causes hearing damage.

OOps, wrong photo.
 

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Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
Mark.
I checked them...I will let you know if the code works.
A few q..though.

Is this just testing the DAC.
We do need a DAC to get an analogue out, right?
What was the complication u said about?
I heard just a steady tone. Is this just to see that if this works.
I hope you can write a mixed siren tone.

Oh yes..Why are VR is used.....as before, do you want me to see that if the code works same way as ur's
 
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Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
The last movie, the tone at the beginning sounds more like it.

If a DAC is not needed then would a 12F629 do?
Cause this is what the initial flasher code was made for by another member for me.
If this is possible my ckt will be even smaller than I thought
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
Hey Mark

Don't over do this.

I think U are experimenting too much, but if you like to ...then be my guest.

The thing is that, if you are not using a DAC, check my PIC options from above post and clarify.
Initially you can give me a standard UK siren code.
This is for a start.
You are there and you will know the sound better.
What do you think?
 

Markd77

Joined Sep 7, 2009
2,806
It might be squeezed onto a 12F629, depends what inputs it needs. If you wanted battery monitoring and flashing lights I think it might run out of pins. If it was just the siren, flashing lights and a couple of switches then no problem.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,750
Ya ..I thought of it too.

Here are some heads up.
I think the siren will be a separate module, as the flasher was.
This way they can make a buck or two on replacements ;)

So what I think the option is .
one 12F629 for the siren, working method is
when powered on the siren should start yelling and keeps on yelling, period.

This was the flasher method.

It is to keep connections and switch additions minimal.

So if you can change the code.
No inputs, no switches, when power is given the PIC should output
Wooooo waaaaaaaa wooooooo, woi woi woi woi :D
something like that. Till power down.

Simplify this way.. it would make things a lot easier.

Battery switching and charging opens another module...more moneeeeeeeeeeeeeey :D
 

Markd77

Joined Sep 7, 2009
2,806
It's sounding more like a siren now. The variable resistor is just for finding the settings that sound right. At the moment it is just a 2 tone siren. The DIP switch is just connected to ground and PORTB 4-7. When RB7 is connected to ground, one frequency is adjusted, RB6 adjusts the other, and RB5 controls how fast it switches between them.
Anyway, video linked to which should make it more clear.

Realplayer should be able to play this video.
http://www.marksphotos.info/siren/MOV00264.3GP



There is no DAC, I don't think it needs one unless the volume needs to be varied in software.

There is a kind of low pass filter to make it more of a sine than a square wave.

 

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Audioguru

Joined Dec 20, 2007
11,249
"Wooooo waaaaaaaa wooooooo, woi woi woi woi"
That's what I say when I see the bikini girls skiing.:D

There are many fresh water lakes with beaches around here and the bikini girls are also there.
When I see them I make the same sounds as the police boats.

Fire trucks have the usual ramping frequency siren plus an extremely loud low frequency buzzer. The buzzer sound penetrates anything and over-rides a radio playing.
 

Markd77

Joined Sep 7, 2009
2,806
Ok.
I thought I'd explain my thought process on the capacitor resistor mess on the output. The 560R and 220nF are supposed to be a low pass filter at 1.3KHz.
The 100R and 20R are a voltage divider to take the 5V peak to peak signal down to 1V for my stereo line in socket and the 100nF is to remove the DC offset.

Nothing blew up, which is good, but is my reasoning OK?
 
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