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Topic: Using MKRZero for high frequency sounds (Read 213 times) previous topic - next topic

SakamotosLfe

Hello guys!!  :)
I'm completely new on hardware engineering and now i need to develop a project with my dad. I can't say much of the project but I need help!
The project consist in a board that will reproduce a sound, doesn't matter what sound, but this sound needs to have a freqency higher than 20Khz and lower than 50Khz. I was thinking on MKRZero, but i have three "versions". The first will need to have 1 buzzer/speaker, and the bigger one 4 buzzres/speakers. The sound need to be loud enough to be hearing at 5 meters distance.
The first version of the project, with just one speaker, need to be really small, you need to carry on your hand. The speaker can stay near the mainboard. The other two can be bigger but the speakers will be away far from the mainboard.

My question is, MKRZero is enough to this? And how to make it? I read at MKRZero forums that DOC0 will stop working if i connect directly to the speaker, is that right? I need a resistor or something?

I searched at Youtube but didn't found anything useful to this project with the MKRZero. There's other board that suits me better?

I read that i just need a amplifier, if is that right, which one it's better? I still need the MKRZero?

And sorry for the english, i'm a brazilian and my browser keeps translating everything!
If you need more information or if I broke any forum's rule, TELL ME! I just want some help!  :smiley-sweat:

Really thanks for everyone and have a nice day!  :smiley-wink:  :)

Grumpy_Mike

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My question is, MKRZero is enough to this?
It depends on what sort of sound we are talking about. Square wave, sin wave, triangle or sawtooth? Or some sort of complex waveform? Fixed frequency or frequency changing through the duration of the sound?

Quote
I read at MKRZero forums that DOC0 will stop working if i connect directly to the speaker, is that right?
Probably as the output current rating is tiny. A resistor will only cut down the sound even further. So you will need an amplifier, and as this is not a normal amplifier because of the frequency you will have to design and test it yourself.

Quote
The sound need to be loud enough to be hearing at 5 meters distance.
Heard by who or should I say what?

You will need at least an oscilloscope to test and build this system, it is not an easy project.

MarkT

The sound need to be loud enough to be hearing at 5 meters distance.
Any idea at all how many dB you want?  That description is essentially meaningless.
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pjrc

How will anyone be able to hear the sound, no matter how loud, at any distance, when the frequency is higher than humans are capable of hearing?

MarkT

#4
Mar 24, 2019, 12:16 pm Last Edit: Mar 24, 2019, 12:17 pm by MarkT
Ultrasound requires transducers capable of the high frequencies involved, and most available
transducers are single-frequency tuned transducers (which can be efficient).

Less efficient transducers are things like ribbon tweeters, some of which go upto into ultrasonic
region. 

Most compression/horn tweeters are optimized for the human ear and you'll probably have
to measure the response beyond 20kHz for yourself, its unlikely to be advertized.

Is this a means of communicating with species which can hear above 20kHz?
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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