Good afternoon,
I'm creating a home alarm, but I'm having difficulty to create a sound of an alarm.
I have 2x NE555 only can not I create a sound way.
or create something like GE NetworX NX-4V2 Home Alarm Security System Siren Test - YouTube Testing The Alarm - YouTube
I wanted to use this siren 12v
someone can give help.
I see the picture, but I don't see any specs... Is that a speaker or a siren?
You can't drive a speaker or a siren directly from the Arduino or a 555. You need to boost the voltage/current.
If it's a siren, you don't need the 555. You hook it up to 12VDC (I assume it runs off 12V?) and it makes noise. (Do NOT connect a speaker to 12V!) In that case, you need a MOSFET or transistor (and a 12V power source) to go between the Arduino and the siren.
If it's a speaker, it typically needs a power amplifier between the 555 sound generator and the speaker. (There are lots of power amp chips available.) Or, in this application you don't really need a clean-linear, non-distorted, audio amp, and you can use a MOSFEET (or two) in non-linear "switching" mode.
P.S.
You should be able to generate siren-like sounds without the 555s by using the [u]tone()[/u] function. (Of course, you'll still need to boost the signal to drive a speaker...)