【ufun learning】Analysis of the buzzing routine

ddllxxrr

【ufun learning】Analysis of the buzzing routine [Copy link]

Buzzer is a good device used by microcontrollers to alert people.

I am more interested in this MLT-5020 because I have studied buzzing, and the bigger the buzzer, the louder it is.

As can be seen from the table above, the operating voltage is 3V, so I thought it would not be too loud. I tried the example program and it was indeed not too loud.

After looking at the routine, I thought that the timer was used to set various frequencies, but the routine is as follows:

int scale(int i)											//ò×±oˉêy
{
	int t;
	for(t=0;t<200000/i*2;t++)
	{
		GPIO_SetBits(GPIOA, GPIO_Pin_8);
		Delay_Us(i);
		GPIO_ResetBits(GPIOA, GPIO_Pin_8);
		Delay_Us(i);
	}
}

I didn't understand the 200,000, but after checking on Du Niang, I understood.

The frequency range of music is about 20Hz---20KHz, and the frequency range of human voice is about 300Hz---3.4KHz. But the highest frequency that humans can hear is 15KHz.

The routine gives the highest frequency first, and then gives different frequencies according to different scales. The *2 at the end is a cycle.

This content is originally created by EEWORLD forum user ddllxxrr . If you want to reprint or use it for commercial purposes, you must obtain the author's consent and indicate the source