PC Speaker: Difference between revisions

When the PIT interrupts you, you need to program PIT timer 2 so that it puts the PC Speaker in the "out" position for a fraction of 60 microseconds. For 8-bit audio, the number of microseconds can be calculated like this:

 

microseconds = (sample * 60) / 255;

 

== Sample Code ==

This will work on real hardware and in QEMU if it started with <code>-audiodev pa,id=speaker -machine pcspk-audiodev=speaker</code>. The code also changes the PIT timer 2 frequency, so you will have to reset that when you're done "beep"ing :)

//Play sound using built-in speaker

static void play_sound(uint32_t nFrequence) {

//set_PIT_2(old_frequency);

}

 

== See Also ==