How do I get rid of piezo speaker ticklish sound?

Projects General Guidance
1

I am using a PKM34EW piezo speaker with a ToneAC library to generate a frequency between 19Khz - 22kHz.

If I were to just send a single tone, I will not hear any tickling sound. However, if I were to alternate the frequency between 19kHz - 22kHz with a '0' in between, I am gonna hear the tickling (Not quite sure what do you call that) sound.

Here is my sketch:

#include <toneAC.h>

void setup() {
}

void loop() {
   toneAC(19000);
   delay(1000);
   toneAC(0); //if I remove this, I won't hear the tickling sound. But if you put your ear very near to the speaker, you can hear it
   delay(1000);
   toneAC(20000);
   delay(1000);
}

Is there a way that I completely remove the tickling sound if I were to call toneAC(0)?

2

Did you connect the piezo between two pins ? or with only one output pin and GND ?

What happens when you use "noToneAC();" instead of "toneAC(0);" ?
What happens when you use "toneAC(100000);" for a silence ?

Are you use that you are hearing the click of "toneAC(0);" or the change from 20kHz to 19kHz. Since it runs in the loop, the 20kHz is followed by the 19kHz.

I was not able to remove the clicks completely myself. The toneAC() is a lot better than the default tone() library, but it is hard to output silence or ultrasonic without hearing something. On the other hand, I can only hear it with from a short distance.

3

Hi Peter,

Yeap. I connected the piezo to pin 10 and 9 respectively.

I did'nt know there is such thing as noToneAC(). However, the result is the same with toneAC(0).