How do I make specific tones with a piezo buzzer?

Question

I am using a piezo buzzer and fiddling around with it a little bit. I currently have different tones with delays in between and I have to do a lot of trial and error for the piezo buzzer to play sounds like I want it to. Is there a better way to do this? because at this rate I will be stuck for a while.

I am trying to get the piezo buzzer to make the sound of an alarm. Any suggestion on how I can get it to sound exactly like an alarm or is trial and error the only way?

Answer 1

It's very hard to know from your question what you are having trouble with. I have a piano and I can hit the keys, but it takes me a long time to hit them in the right order and with the right timings to create a new symphony.

Anyway, if creating the sounds is the problem, have you looked at the Tone library?

Different alarms have different sounds. I once heard an alarm which sounded like the start of Fuer Elise, so probably the notes were E and D#. That would make their frequencies about 330Hz and 311Hz:

void loop()
{
    tone(pin, 330, 250);
    delay(300);
    tone(pin, 311, 250);
    delay(300);
}

The sound you linked to sounds to me like it starts on a C, and slides up gradually one octave. One octave higher is double the frequency, so this code should do that:

void loop()
{
    const int startFreq = 523;  // C5 is 523Hz

    // Start at the given freqency, and increase gradually by
    // one octave (double the frequency)
    for (int freq=startFreq ; freq<= (startFreq*2) ; ++freq)
    {
        tone(pin, freq, 10);
        delay(3);
    }
}