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Alarm MP3 & chips and hardware

Hi,

I'm working on a homebuilt circuit, that will provide an anti-theft alarm for a bicycle.

I've been going down the routes of looking at various 555 timer circuits, making various beep beep noises, but prefer the sounds of some of the free mp3 sound files that are out on the net.

I've downloaded some of these files, and am wondering how I could put them on a memory chip of some type, and then be able to 'output' them at appropriate times, into a loud speaker..

Clearly, I'd need a chip to interpret the files held on the ROM chip (?), before it's output to the speaker? What would that chip be? Are there any off the shelf chips to do this sort of thing?

Sorry, I can't be more specific, as I don't know too much about electronics.

Thanks Jeremy Watts

Reply to
jwatts1970
Loading thread data ...

Hi Jeremy,

There are a bunch of ways to do this, but since you say you're somewhat inexperienced in electronics I'd try one of these:

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There are special purpose ICs that they crank out by the millions for "Obama Birthday Greetings" cards, etc - that's what's under the little blob on the board. You can ditch the switches and wire up your own speaker and amp for the alarm, record in your sound, and rig up your trigger circuit to the board's terminals in lieu of the playback button.

Shipping from China might take a week or two, but for a buck you can hardly go wrong.

Reply to
bitrex

Are

Cheers

Reply to
jwatts1970

OK, you want to "build" your own device.

If you really want to do that, you need to do more homework.

As a starting point:

1) learn what an MP3 file is. 2) learn about solid state storage devices 3) learn about how to program a device that will take advantage of the devices in 1 & 2.

Let me help you out:

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with About 73,600,000 results (0.14 seconds)

you should be able to see what needs to be done.

Your Welcome

PS: Second link will tell you every thing you need to know.

Reply to
hamilton

On Saturday, October 6, 2012 3:58:58 AM UTC-7, snipped-for-privacy@googlemail.com wrot e:

mp3 decoder.

Yes.

But you need to know the trade-offs. MP3 is Discret Fourier Transform (DFT ) of time domain samplings, so you need to reverse the transform before out putting to the speaker. Storing/outputting the real time audio samples mig ht be easier, but it would take more than 10x memory storage.

Reply to
linnix

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