"Ping" device - does it or does it

ALIBE

guys,

Can someone who's using tjhe ping device confirm or correct to me please.

When the Ping device is hooked up to suppose your prop, do you see it making "chirp" sounds especially, when you have a 1 sec pause btwn each method calls to ::Inches ::Millimeters ??

I was told by the Parallax tech support that one should not be able to hear anything due to the high freq nature of the sound. I however experienced otherwise from my experience w/ SRF08 and was later on told by one of my buddies who's using Ping that he does in fact hear feable chirp sound.

Have I lost my mind.

thanks, ALIBE



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ALIBE - Artificial LIfe BEing. In search of building autonoumous land robot

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Mike Green

There are some people who might have some ability to hear very high frequencies, possibly a submultiple (14 kHz). The younger you are, the more likely you are to have an audible response. When I was younger, I could hear the sound of the flyback transformer in my tv (15 kHz) faintly.

Ken Gracey

Hey Alibe,

I'm no scientist or ultrasonic expert, but I often hear a "click" from the Ping))) when I listen carefully. The clicks increase with the proximity to the object under measurement. The Ping))) firmware takes more measurements as the object nears the module. Perhaps this is the ultrasonic sound starting and stopping.

Ken Gracey
Parallax, Inc.

Ym2413a

Mike Green said...
hen I was younger, I could hear the sound of the flyback transformer in my tv (15 kHz) faintly.

I work in a television production room and I hear the 15.7Khz like clear day.
It starts to drive people here up a wall when you get 6 NTSC monitors running at once all generating that high frequancy tone.

IAI-Captain

Alibe:
·
I'm using da Ping wid da Prop, OK!
·
And To tell you the truth, I did not hear anything until reading your post in this thread.
·
what I hear is a clicking sound @ 3 to 4 clicks /sec. the sound is very faint.·to hear it·I must place my ear right up to the Ultrasonic transducers.
So, I guess that, when I do this, I am·speeding up clicks by placing my head closer to the sensor.
·
But I got to let you know that, @ no time do I hear any ultrasonic sound/s. all so it does not seem to be bothering the cat.
so it can't be to bad!
I guess, Maybe you should·get your hearing tested. Maybe an audiologist can tell you why you hear it when others don't.·
·
good luck

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IAI (Indigenous Alien Intelligence),
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parts-man73

Sometimes when our Cable box gets turned off, but the TV accidently gets left on. I can tell as soon as I walk in the room that the TV is on, even thought the screen is blank. It drives my wife nuts, I say "The TV is on" and she swears it's off. It must be the flyback transformer that I hear. It probably drives her nuts because I hear a very faint high pitched noise from the TV, but I sometimes "tune her out"

I also used to hear when I was a kid when my mother left the electric stove on. I could hear what I assume was a relay cycling the burner on and off.

Brian

Tracy Allen

I think Ken is right about the sounds starting. There is a sudden onset of a pressure wave, and I think that sudden onset has a wide frequency spectrum that can be heard as a click. I can often hear those when someone has a "pest repeller" in operation. Closer to my work, for animal behaviour researchers we have made devices that produce a soft onset ping--they were hearing audible components. The soft onset is accomplished (with an SX chip) through an envelope of increasing pulse width into an LC filter. The PING)) needs a sudden onset to make the sharpest possible echo.

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Tracy Allen
www.emesystems.com

ALIBE

thanks all for your comments and confirming the audibility of the clicks.

Ken, Tracy;
it makes sense as I read your explanation.

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ALIBE - Artificial LIfe BEing. In search of building autonoumous land robot

http://fstop.crosscity.com/
http://icar.crosscity.com/
·

Chris Savage

ALIBE said...(trimmed)
Can someone who's using tjhe ping device confirm or correct to me please.
When the Ping device is hooked up to suppose your prop, do you see it making "chirp" sounds especially, when you have a 1 sec pause btwn each method calls to ::Inches ::Millimeters ??
I was told by the Parallax tech support that one should not be able to hear anything due to the high freq nature of the sound. I however experienced otherwise from my experience w/ SRF08 and was later on told by one of my buddies who's using Ping that he does in fact hear feable chirp sound.

ALIBE,

·· I was the Tech you spoke with.· What I said was that you cannot hear the 40 KHz pulses that the transducer is sending.· You used the term, "chirp", which to me sort of implies a high frequency noise.· In fact there is a very faint click sound coming from the PING))) when it is emitting the pulses, but that click is nowhere near the 40 KHz range, which you cannot hear.· As Ken and Tracy pointed out there is noise generated during the creation of the pulse which could also be compared to distortion in audio speakers.· I had explained this to you when you mentioned the SRF module making that noise.· Again, I just wanted to be clear that the click is nothing more than noise and is not the actual 40 KHz pulse, as it is possible to hear the click regardless of the frequency being emitted.· I hope this clarifies my earlier comments.· Take care.

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Chris Savage
Parallax Tech Support