xoscope_2.0.3.2 pet soundcard oscilloscope

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mister_electronico
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Hi Rodney Byne

#21 Post by mister_electronico »

Hi Rodney Byne

Maybe perhaps are not snoring are voices that want to say something ..... LOL... LOL... LOL. :lol: :lol: :lol: :lol:


I am work Spanish Broadcasting Electronic Technician I work in the maintenance and operation in A.M and FM transmitters, RF links...

The psicofonias are phenomena that have no explanation, but it is true that there are


Sorry for all this is out of the scope this forum, but good is always sympathetic to skip the rules to laugh a little.

Last summer I was in Peru and I pass through a town where people told me that there was a haunted house.

Well leave the recorder to record hours in the night and record voices of children laughing and crying too .

I have one psiconia here, in my house in the village , the village is tiny no noise , no sound, all is silent , stone house with walls the 1 meter wide.

This small psicofonia I did when I was there, the recorder stops recording all night, I and another player to questions,


In the audio I send my voice can be heard asking in Spanish ....
What is your name ? and the sudden shock and begin to hear a voice responds .


I know that I just converted to the forum buffoon . :lol: :lol:


Other voices I have recorded elsewhere, always checking that they could not come from external sources .

Good does not have any explanation , but .... this is there real.

I'll leave the full audio.

And they answered me again but this time the voice cleared by program audio with Puppy.

Anyway Puppy is even useful for all this.

Greetings and happy weekend.

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https://misterelectronicoes.wordpress.com/
Attachments
psico_1203.mp3.gz
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psico_1202.mp3.gz
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Last edited by mister_electronico on Sun 08 Feb 2015, 18:35, edited 1 time in total.

Rodney Byne
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pc soundcard input protection.

#22 Post by Rodney Byne »

Hi to All.

I will listen to the above interesting sound files and comment shortly.

First a serious tech contribution to complement the use
of xoscope, siggen and Baudline on a pc, laptop or netbook.
I have one of these always to hand on my test bench.

For those people who want a simple audio lab on their pc using
these and similar programs, I suggest including the attached mic
or line socket protection circuit to prevent accidental overload
of the sound card or motherboard sound module.

A sudden instantaneous high amplitude pulse signal will do
total expensive damage to these devices without protection,
so normal signal inputs should not exceed about 150mv RMS,
before top and bottom clipping occurs.

The Mic fader should be up about 1/3rd and Mic s/w boost must be off.

This is an easy safety project to construct on say veroboard
or tagboard, at very little component cost for big savings in
potential repair bills.

For those interested, the four diodes clamp the input
signal at top and bottom to about half a volt pk-pk.
The 470n capacitor blocks the phantom +3v dc coming OUT of the
mic socket, which would normally supply a fet microphone insert.

Believe me, inclusion of this circuit is well worth the effort.

Regards.
Attachments
pc mic protection.jpg
slide 4
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mister_electronico
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Very good observation

#23 Post by mister_electronico »

Very good observation, Only one thing to consider with the with the capacitor 470 nF.

The impedance the capacitor 470n F

Zc = 1 / (2*pi*f*C)


With 20 Hz Zc near to 17 Kohm

With 20.000 Hz Zc near to 17 ohm

Is a high pass filter.

So maybe the cheap way is for example:

http://www.allaboutcircuits.com/vol_2/chpt_8/4.html

The next scheme not tested but may be a solution.

It would be better with a band pass filter operational but this would complicate the circuit.


Image


regards

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https://misterelectronicoes.wordpress.com/
Last edited by mister_electronico on Sun 08 Feb 2015, 18:36, edited 1 time in total.

Rodney Byne
Posts: 247
Joined: Fri 31 Jan 2014, 14:12

keep it simple

#24 Post by Rodney Byne »

I listened to the sound files, if a bit short so couldn't
form an impression without being there, but a paranormal
expert might be interested.
-------------------------------------------------

Thanks for the added equalizer section but as you say,
better to keep the protection circuit simple.
The component values and configuration could
be useful though in another, different application.

Besides I want to discourage the lf response.
Lf should be rolled off downwards, don't like it.
Lf is a nuisance, having possibility of earth hum loop
disturbance and power supply breakthrough.
If anything it might be better to reduce the 470n to 100n
and also run the laptop from batteries.
Final cap value rests with the user, but 470n is a good start.

For the purpose of meaningful analyzer examination
of audio circuits, I think it better to concentrate
on frequencies above 1khz.

Cheers

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mister_electronico
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You are in true

#25 Post by mister_electronico »

Hi Rodney Byne

Psiconia:

The small audio file belongs to a recording of may be 10 hours or so.
My recorder Sony is not very expensive, I think it cost me about 70 euros, but records clean sound. The voices are low and lose quality when I raise them by mhWaveEdit volume.

During the 10 hours nothing happens except in small moments that appear voices.

I have not devoted much time to this.

Anyway as I said this topic is out of this forum and the only thing interesting is that Puppy programs can also be useful for things like this.

----------------------------------------------------

With respect to the schema you're right, it is better to focus on frequencies above 1khz.

So your scheme is perfect.

If I have time and could get with some frequency converter circuit for xoscope and multiplier for siggen.

Anyway there internet projects.

I want to retire soon, but my government is just the opposite.

This is illusions I still have much.

Right now I'm also involved with a project for Puppy.

| Microcontroller -- RS232| < == > | Program C | <==> | Gtkdialog|

For data aquisition and presentation.


Thanks Rodney Byne quite enjoy chatting with you about these issues.

See you.


______________________________________________________________________
My blog

https://misterelectronicoes.wordpress.com/
Last edited by mister_electronico on Sun 08 Feb 2015, 18:36, edited 1 time in total.

Rodney Byne
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An audio level meter

#26 Post by Rodney Byne »

Hi again mister_electronico,

Quickly going back to your previous post,
IF I wanted to lift the lf end of the audio spectrum
I would just increase the value of a coupling cap
from a smaller value to about 10microfarads
to pass 20hz.
For this simple application, I wouldn't bother with
a bandpass filter at all.

The insertion loss of any such filter into its
termination Z would be self-defeating,
unless the facility exists to compensate by
amplification.
--------------------------------------------------------

Now, my last thought to complete a self-contained pc
set of audio lab analysis programs in Puppy, is an
absolute input audio level meter in millivolts of 10 to 100,

Although there are plenty of Windows programs
for this purpose which can run in Wine, could you
write a pet having an indicator and simple front panel
gui to calibrate against an external millivoltmeter?
Sorry, I'm a practical man knowing nothing of code,
it's way over my head.

No pressure just have a think, could it be done
at all. I will leave that with you.

Cheers.

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mister_electronico
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I forgot one thing

#27 Post by mister_electronico »

I forgot one thing leave your scheme in Spanish forum for people to see, I hope you do not mind.

I hope you do not ask copyrights.

http://www.murga-linux.com/puppy/viewto ... 275#765275

Thanks .. see you.



______________________________________________________________________
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https://misterelectronicoes.wordpress.com/
Last edited by mister_electronico on Sun 08 Feb 2015, 18:37, edited 1 time in total.

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mister_electronico
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Hi Rodney Byne

#28 Post by mister_electronico »

Regarding the filters think your scheme is a good base, and then according to the needs of signal levels or frequency as may be modified according to the needs.

-----------------------------

Regarding millivoltmeter the only way that I have the do now:

| Microcontroller -- RS232| < == > | Program C | <==> | Gtkdialog|


At this time I managed to capture the data with the microcontroller and entirely by the program in C to pass gtkdialog program.

But I have problems with the C program that is not stable with the reception of data.

And this is the last thing I'm debugging.

But this way you would have to use microcontroller and maybe this will complicate your project.


Another way you could do serious thinking about it entirely by the sound card.

I have no experience in this, or how to aquire data from the sound card.


But as the sound card does not collect stable DC voltage values​​, you could mount a VCO, which CC values ​​changed frequency and using the card values ​​captured by presenting them as voltage values​​.

But as I say I have no experience in this.

Anyway when I finish my project I will put an example to capture data for microcontroller Puppy.



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See you Rodney Byne
Last edited by mister_electronico on Sun 08 Feb 2015, 18:37, edited 1 time in total.

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Moose On The Loose
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Re: Hi Rodney Byne

#29 Post by Moose On The Loose »

mister_electronico wrote:
Regarding millivoltmeter the only way that I have the do now:

| Microcontroller -- RS232| < == > | Program C | <==> | Gtkdialog|
If the microcontroller predigests the data a little, you can script in Bash.


It seems to me that external electronics could also be made to precondition the analog signals so that a sound card could be used to get calibrated results. Sound cards use a delta-mod ADC so abrupt changes in the input to the ADC will cause the output to be bogus but if we assume that the edges get smoothed off, here is my idea:

We need a few controlling signals for the circuit so I will suggest a really bad way to get them:

Use a USB <--> RS232 adapter to make it so a script can send characters to the external circuit. In the external circuit, use a transistor to make RS232 levels into logic levels.

The character 7F or FF causes short pulses out of the transistor.
The character 20 or the like causes long pulses

A simple RC low pass from the logic level signal to the D of a 74HC74
A direct wire from the logic signal to the clock of the 74HC74

You now have a way to control an analog switch like a 74HC4053 to select between the calibration tone and the live signal.

So far we have only used 1 section of the 74HC74. The other two can be made into inverters by just having them select +5V and Ground for 0 and 5V in. One of those 5V's is the output of the 74HC74 for a reason I will explain below.

These inverters can by used to make a classic logic gate oscillator. If your 5V is in fact a reference and not a regulator, you will have nearly exactly 5Vp-p from the oscillator. A simple RC circuit can round it off AC couple and attenuate it.

The reason to make one of the inverter sections abnormal is so that when you select the live signal the oscillator is disabled. It has another advantage that is less obvious. When you select the calibration signal, the AC coupling will cause the base line of the rounded squarewave to slide from zero volts down to about half the peak to peak. A little clever code can look at this as a test of the low frequency behavor of the sound card.

I hope you get my drift here. :wink:

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mister_electronico
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Hi Moose On The Loose

#30 Post by mister_electronico »

Hi Moose On The Loose .

Yesterday I found a program that I think I can do everything much easier.

this Frecuenty.py program written in python captures the signal and displays the frequency microphone.

My idea is this.

A voltage converter Frequency (Hardware) ==> PC microphone ==> Frecuenty.py + Program C ==> gtkdialog for presentation.


The voltage converter Frequency can be for example a LM131

http://www.google.es/url?sa=t&rct=j&q=& ... ms&cad=rja

Or maybe the 4046

http://www.google.es/url?sa=t&rct=j&q=& ... ms&cad=rja


Once converted to frequency the voltage gets to adapting it to microphone input, the program detects Frecuenty.py frequency, and a Program C will converting the frequency again in voltage.

Finally the program presented in a gtkdialog display the value of the voltage.

With this method will later be able to measure amps, resistance, Farad, .......

Here is the program.


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mister_electronico
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The next to do.

#31 Post by mister_electronico »

Frecuenty.py.gz download the file unzip it and then run for the terminal.

python Frecuenty.gz

You need python installed, this is a very simple program we show the frequency display is entering the microphone.

This can help a lot things that I did not have any method to get the value of the frequency.

I can read data from the serial port integers.
In windows getting read bit by bit RS232 data in Turbo C, this could implement measures of external Tension, but I have not gotten Linux.

I think with this program in a month I may have ready a Pet program.

Could end up before but I am very busy lately working.


See you.


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https://misterelectronicoes.wordpress.com/
Last edited by mister_electronico on Sun 08 Feb 2015, 18:38, edited 1 time in total.

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Moose On The Loose
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Re: Hi Moose On The Loose

#32 Post by Moose On The Loose »

mister_electronico wrote:
A voltage converter Frequency (Hardware) ==> PC microphone ==> Frecuenty.py + Program C ==> gtkdialog for presentation.
The idea is a good one for resolution but not so good for accuracy of calibration..

The good old 555 timer can be made to work as a V to F
The LT6900 or LTC6991 can be made to work as a VCO.
The voltage converter Frequency can be for example a LM131
{/quote]
I think the LM131 may be hard to get.

Or maybe the 4046
The 74HC4046 may be worth a look. You can do some clever (off data sheet) things with them. The R1 and R2 connect internally to current mirror like circuits. We may be able to make the thing calibrated with a bit of cleverness on them to make it compensated for temperature etc.


AD654 is also worth a look. IIRC a 10nF NPO ends up being what sets the accuracy in a good design. The resistors and the device its self generally are better than the best capacitor you can get.

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Hi Moose On The Loose

#33 Post by mister_electronico »

Hi Moose On The Loose
The idea is a good one for resolution but not so good for accuracy of calibration..
I'm not too worried about calibration, for this I can adjust by software.

I'll give an example

Suppose we design a circuit that has the ability to measure voltage between 0V and 10V.

And to 0V I assign a frequency of 1000 Hz for microphone input.

10 V And I assign a frequency to 2000Hz frequency input.

But due to the calibration if it is logical that a 5 V give me a frequency of 1500 Hz, but actually gives me 1600 Hz

I would not worry about that software will adjust.


I think AD654 maybe is perfect for this project .


See you.


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Last edited by mister_electronico on Sun 08 Feb 2015, 18:38, edited 1 time in total.

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Moose On The Loose
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Re: Hi Moose On The Loose

#34 Post by Moose On The Loose »

mister_electronico wrote: I think AD654 maybe is perfect for this project .
This is mostly for others who may be reading along. I figure you have already got there but someone who wishes to copy the idea may be helped by this.

The AD654 turns voltage into frequency making the span of frequencies produced perhaps from 1KHz to 2KHz.

A fairly crude digital filter after the ADC of the sound card can remove the DC AKA the average from the data. This can then be followed by a fairly crude low pass filter to clean up any high frequency noise.

At this point, you have digital values that represent a rounded off squarewave that you wish to know the frequency of. You may be temped to simply count how many times per second the numbers change from negative to positive but you can do way better.

Since simply counting gives you an answer that is give or take one, with a 1KHz signal, you only get a 3 digit number. You can do quite a bit better with this:

Look along the data for the first zero crossing where the numbers go negative to positive. Remember when that happened. Name it T0

Starting at the next crossing count from zero to the one just past one full second later. Call how many crossings N and the time T1.

Note that the time (T1-T0) is not exactly a second but that:

F= N /(T1 - T0)

is a very good measure of the frequency. You get more than 3 digits this way. If you have set the sound card to 16KHz sampling rate, you get just a little better than 4 digits from just doing it in terms of sample number.

You can do a bit better because when the numbers went something like:

-100, -25, 50, 125

You could do a straight line between sample #2 and #3 and estimate when the zero crossing happened between the two samples. This will get you about one more digit.

If this is still not good enough, you can do this:

We are only taking T0 and T1, if we remembered the time of the crossing after T0 and the next one after T1 making T0A, T0B, T1A and T1B we could do:

FA = N / (T1A - T0A)
FB = N / (T1B - T0B)


F = (FA + FB) / 2

This can be extended to average together 100 readings. Those who did a statistics class would expect the average to be sqrt(100)=10 times better. In practice, it tends to come in better than that. The reason has to do with how noise is on a sound card. Down near 1KHz, they are quite good but up near 20KHz where human hearing starts to get bad, they are not as good. Effectively averaging T1A and T1B by the average we take of FA and FB, strongly rejects the effect of the noise at higher frequencies.

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Hi Moose On The Loose

#35 Post by mister_electronico »

All this is very well but so far I have no knowledge to program sound card and capture data as you say, the only thing I have is the Frecuenty.py program.

I hope to capture the frequency Frecuenty.py program reasonably well.

And indeed as you say we will have to adapt square wave output of the AD654 to become a sine wave with a good filter.

This week I will do tests as Frecuenty.py program captures the frequencies from a frequency generator.

Like I said I do not care that is not perfect, I can fix that by sotfware.

I'll schedule it in a month I hope to have it finished.

See you.

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Last edited by mister_electronico on Sun 08 Feb 2015, 18:39, edited 1 time in total.

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#36 Post by greengeek »

Hi mister_electronico, I just used your xopet and it is working well for me using a modified Slacko5.3.3t puppy (I did need to use the extra lib you posted too). This is very interesting. Straight away I was able to display the waveform of my voice through the microphone. I am hoping to be able to use this to display the voltage waveform produced by a small stepper motor which I am using to generate electricity.

The stepper has a series of permanent magnets that rotate inside a group of coils. I guess all I need to do is make an interface to isolate the generated voltage from the audio card input and see what waveform and voltage I have. (EDIT - the waveform will not be high frequency as it is just going to be turning at around 100 - 200 rpm or something like that)

Do you know if xoscope is able to display two separate channels at once? I see it has 8 channels, but all of them seem to be displaying the same signal on my machine - yet I only have one microphone plugged in. (I will have to investigate adding a second soundcard too - probably that is how the extra channels need to operate)

EDIT :OK, now I have looked through the whole topic and got a better idea of how this works.

NOTE TO SELF - build the protection circuit posted by Rodney here

Also note possible interface circuit module described here

Homepage for xoscope here

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mister_electronico
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The reply

#37 Post by mister_electronico »

Hi greengeek is nice to see what xoscope that is useful

Please be careful with microphone inputs that are very sensitive , and if you put a high voltage will produce a breakdown in you sound card .

Follow the recommendations in the post Rodney Byne

http://www.murga-linux.com/puppy/viewto ... 114#765114

Note that the stepper motor or any engine produce large voltage transients that might break your sound card.


With what would be best to put an isolator between the engine and the sound card as an operational buffer as input separator.


Both microphone inputs are available independent you have.

Note that many of those selling microphones have a stereo plug, but the microphone is mono, so that you see the same signal at the two sites.

I think the other channels are reserved for other equipment that you can use as ProbeScope and bitscope, but do not know how these work.

You can place signs at different levels for a closer look inside the toolbar select Channel, then modify the Scale and Position of that channel.

If press the same time the keys Shif+? show you the Help in the window of xoscope.


Ok greengeek good luck with xoscope.

See you.

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https://misterelectronicoes.wordpress.com/

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