here is the tone generation code I am using in a larger program. I clipped it out and changed it a little, and i was unable to test it in this modified form but it runs well in my program. ...
Any on can use this for fun or profit :)
cheers
ps. I will add this to github.com as soon as I figure out how to add a repository. :)
/*
*************************
* Created 9 Aug. 2010 *
* by James Wilson *
* *
*************************
_______________________________________
*/
// ************************************************************************
// Sound generator
//*******************************************************
// this will generate a square wave at a given frequency on the pin
// defined by the "SPEAKER_PIN" definition. I used Timer number 2 but
// if you need to you can change that as well.
// cheers.
// I clipped this from a working program and modified it a little so
// if you have any problems with it let me know.
// use : enter in a frequency in to playTone(int playfreq)
// and turn the tone on or off with SoundGen( {true / false} );
//
#include <stdlib.h>
void SoundGen (int soundOn);
void playTone(int playfreq);
void handler_speaker(void);
#define SPEAKER_PIN 13 // you can change this if you want this is the pin that the sound comes out.
#define SOUND_PERIOD 2000 // Start period for the sound in microseconds this is just a test frequency.
// this frequency is used if none is set in playtone()
byte toggle = 0; // the present state of the speaker pin
void setup()
{
// Set up the speaker to make a tone
pinMode(SPEAKER_PIN, OUTPUT);
// Setup Timer
Timer2.setChannel1Mode(TIMER_OUTPUTCOMPARE);
Timer2.setPeriod(SOUND_PERIOD); // in microseconds
Timer2.setCompare1(1); // overflow might be small
Timer2.attachCompare1Interrupt(handler_speaker);
Timer2.pause();
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// MAIN program
// Main program
int play=false;
void loop(){
if (play = false) { // only want to start playing the sound once
playTone(1000); //enter frequiency here
SoundGen(true); // turn it on or off here
}
play=false;
}
//************************************************************************
// Turn sound generator on or off
//************************************************************************
void SoundGen (int soundOn){
if (soundOn) // turn the sound on or off
{
Timer2.resume();
//SerialUSB.println("SoundOn");
}
else
{
Timer2.pause();
}
}
//************************************************************************
// The playTone command
// Possible change here
// incorporate a duration value
//************************************************************************
void playTone(int playfreq){
char freq[6];
playfreq = 1000000/playfreq; //change it to period
Timer2.setPeriod(playfreq);
}
//************************************************************************
// interrupt handler for speaker
//************************************************************************
void handler_speaker(void) {
toggle ^= 1;
digitalWrite(SPEAKER_PIN, toggle);
}
