Subject:
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Re: Range of RCX sound production
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Newsgroups:
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lugnet.robotics
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Date:
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Wed, 18 Aug 2004 16:56:32 GMT
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Viewed:
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1206 times
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Hi Brian,
I examined the RCX ROM sound routine, and it provides a lower bound of
frequency 31 (matches what your ears told you), and an upper bound of 20000
(also as you noticed).
I'm not sure about the sound hardware, but you might be able higher
frequencies by writing your own H8 code. I dunno if this could damage your RCX,
Caveate Emptor!
I'm told that you can use your sound card as an oscilliscope. If you have a
microphone, a sound card, and (free) software, you can do your own sound curve
analysis. Your miileage may vary depending on the microcphone you use.
Kevin
In lugnet.robotics, Brian Davis wrote:
> In the "what other weird questions can Brian Davis come up with", here's one
> I've not been able to locate on any website (including the Mindstorms Internals
> site), and I can't test it easily with my ear:
> What's the frequency range for the RCX sound production?
> By playing a tone and then increasing it till I lost the sound. It remains
> loud & clear until about 5000 Hz (PlayTone(5000,100);), and then seems to get
> softer, but is still audible at 7.3 kHz. Beyond there there's still sound being
> produced weakly (to my ears) to 15 kHz, with a distinct "click" audible between
> tones. Between 15 kHz & 17.3 kHz there is still a trace of sound, but very very
> weak and (again, to my ears) atonal. Above 17.3 kHz, I hear only the "click"
> between tones, and above 20 kHz this ceases abruptly. Note that usually I can
> hear the tone put out by a TV without a signal going in (26 kHz? IMS, & it
> probably doesn't), but the scan tone from a TV is rather loud (I don't hear it
> that way, but measuring the audio power shows it's a "loud" source).
> So, does anybody have a audio spectrum analyser handy, and can see just what
> the RCX is putting out at these very high frequencies (it would be great to have
> something like a graph of power vs. frequency).
> The low end is easier - it seems to make sound (OK, a series of clicks) down
> to right around 32 Hz, cutting off below that.
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Message has 1 Reply:
 | | Re: Range of RCX sound production
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| but a microphone was its own frequency curve in which you need to compensate. ----- Original Message ----- From: "Kevin L. Clague" <kevin_clague@yahoo.com> To: <lego-robotics@crynwr.com> Sent: Wednesday, August 18, 2004 12:56 PM Subject: Re: Range (...) (20 years ago, 18-Aug-04, to lugnet.robotics)
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Message is in Reply To:
| | Range of RCX sound production
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| In the "what other weird questions can Brian Davis come up with", here's one I've not been able to locate on any website (including the Mindstorms Internals site), and I can't test it easily with my ear: What's the frequency range for the RCX sound (...) (20 years ago, 18-Aug-04, to lugnet.robotics)
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