Alternative to Arduino tone() method

Question

Is there any easy easy way to play tones on a piezo buzzer with the Arduino other than the built in tone() method? I only need to call it a couple of times, but I notice that when I use it there is an extra 1256 bytes added to the output size! I realize that on a normal Arduino this would't be a whole lot out of the 16KB available, but I'm trying to do this on the ATTinyX5 series. I'm currently using a t45 but would like to be able to use the t25 if at all possible and that extra 1256 bytes puts me well over the 2048 byte limit.

Thoughts?

Answer 1

There's the Melody example on the Arduino site that just uses digitalWrite to quickly toggle the I/O pins:

void playTone(int tone, int duration) {
  for (long i = 0; i < duration * 1000L; i += tone * 2) {
    digitalWrite(speakerPin, HIGH);
    delayMicroseconds(tone);
    digitalWrite(speakerPin, LOW);
    delayMicroseconds(tone);
  }
}

The main disadvantage to this over other methods such as using a timer output is that your code will be stalled while the tone is being played, and if you have background interrupt activity occuring you may end up with a few anomalies in the tone.