EEVblog Electronics Community Forum

Electronics => Beginners => Topic started by: jasonbrent on September 01, 2013, 12:23:10 am

Title: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 12:23:10 am
Folk,

I just received my first 'real' oscilloscope this week (after going through a couple of trial scopes)... I saw something I thought was pretty neat at http://www.johngineer.com/blog/?p=648 (http://www.johngineer.com/blog/?p=648) and decided to see if I could reproduce it.

I'm using an Arduino Mega instead of the Uno (I think it what he used...) and trying to present this on my DS2012 in XY mode.

However, what I get back out is... really far from that type of visualization... it honestly looks like a jumble of dots.

I've tried to simplify by just writing 4 points on the screen to form a square type presentation, but that doesn't really come out properly either.

If I put the scope in Y-T mode and turn ont he time delay function, it looks like the X and Y positions may be coming through properly (Sorry, I can't yet screen shot and upload from my Rigol for an example).

So I'm wondering if anyone has tried to do something similar with a digital scope like the Rigol, and if so, what modifications if any were necessary to the code and/or screen configuration on the rigol?

My level of explanation and questions here likely suggest that I'm clueless.... and when it comes to EE type stuff, I am at the moment, but attempting to learn. ;-)

Thanks for any input/advice.

EDIT: My scope has the latest firmware in place so the X/Y reversing bug should be fixed...

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: c4757p on September 01, 2013, 12:31:31 am
X-Y mode on a digital scope doing anything more than simple Lissajous figures?  Hahahahahahahahahaha

Edit: The Tek 2230 he shows is a combo analog+digital scope. That's why it worked for him.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 12:37:07 am
X-Y mode on a digital scope doing anything more than simple Lissajous figures?  Hahahahahahahahahaha

Edit: The Tek 2230 he shows is a combo analog+digital scope. That's why it worked for him.

Alright... that's what I figured... the only analog scope I have (tek 7603) doesn't have an X-y mode. oh well. :-)

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: poida_pie on September 01, 2013, 01:14:40 am
I just did it using my DS2072 and the Tek 475
No problems.
On the Rigol, you need to choose a fast update rate for the X-Y mode, this is done via the Acquire menu, sample rate.
The display changes markedly depending if you choose 7K points compared with anything else.
I suspect maybe you have it on "AUTO" memory depth which ends up being 7M points and far too slow.

Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: poida_pie on September 01, 2013, 01:16:13 am
here is what the DS2072 looks like
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: c4757p on September 01, 2013, 01:19:12 am
Well I'll be damned. That looks nice. :-+ I guess the 2072 got X-Y right. A lot of the older ones sure as hell didn't.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 01:59:14 am
here is what the DS2072 looks like

Ah, I must be doing something wrong then. I'm guessing it's my circuit... OR some timing issue with the Mega vs. the Uno. I'll keep trying. :-)

thanks!

EDIT: This is as close as I ever seem to get....

EDIT2: Fixed. The issue with the Mega is that it has a larger number of PWM output pins than the UNO. The example code sets up timer 0 (TCC0A and TCC0B). On the Mega, timer 0 controls PWM output pins 13 and 4.... by simply modifying the output pins, this now works on the mega and the DS2102.

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: casinada on September 01, 2013, 04:25:20 am
The Tektronix 7603 definitely has x-y mode. You have to have the right horizontal time base plugin such as the 7B52. I think it is also possible to use a vertical amplifier on the horizontal slot to use the x-y feature.  :)
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: M0BSW on September 01, 2013, 10:44:50 am
Folk,

I just received my first 'real' oscilloscope this week (after going through a couple of trial scopes)... I saw something I thought was pretty neat at http://www.johngineer.com/blog/?p=648 (http://www.johngineer.com/blog/?p=648) and decided to see if I could reproduce it.

I'm using an Arduino Mega instead of the Uno (I think it what he used...) and trying to present this on my DS2012 in XY mode.

However, what I get back out is... really far from that type of visualization... it honestly looks like a jumble of dots.

I've tried to simplify by just writing 4 points on the screen to form a square type presentation, but that doesn't really come out properly either.

If I put the scope in Y-T mode and turn ont he time delay function, it looks like the X and Y positions may be coming through properly (Sorry, I can't yet screen shot and upload from my Rigol for an example).

So I'm wondering if anyone has tried to do something similar with a digital scope like the Rigol, and if so, what modifications if any were necessary to the code and/or screen configuration on the rigol?

My level of explanation and questions here likely suggest that I'm clueless.... and when it comes to EE type stuff, I am at the moment, but attempting to learn. ;-)

Thanks for any input/advice.

EDIT: My scope has the latest firmware in place so the X/Y reversing bug should be fixed...

-jbl
,
You won't go to far wrong if you contact Alan W2AEW on here.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: Rigby on September 01, 2013, 12:11:48 pm
X-Y mode on a digital scope doing anything more than simple Lissajous figures?  Hahahahahahahahahaha

Edit: The Tek 2230 he shows is a combo analog+digital scope. That's why it worked for him.

Alright... that's what I figured... the only analog scope I have (tek 7603) doesn't have an X-y mode. oh well. :-)

-jbl

I have a 7633, and it has X/Y mode.  If you find the manual for the module in your horizontal slot (and that module supports X/Y mode) the instruction manual will tell you how to do it.  You wind up plugging the X signal into the "MAIN TRIG IN" BNC of the horizontal module and the Y signal into the vertical module normally.

I am glad to see that the Rigol DS2000 series displays it properly, though; this is likely to be my next scope.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: dentaku on September 01, 2013, 01:26:43 pm
I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 09:01:40 pm
I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.

Hmmm. I guess in order to try to replicate this, I'd need to to be able to play two different audio tracks at once, in sync, out two outputs, each connected to a channel on my scope. I'm not sure how to do this without some research first.... I could probably cheat and add a second audio card into my computer and I'm pretty sure I could sync play two tracks out two outputs under linux... definitely not sure how to do it under windows with the integrated audio (I have discrete outputs 1/8th" outputs, at least...).

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: Hydrawerk on September 01, 2013, 09:16:32 pm
I tried a similar thing with my DSOX2002A. https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick!/msg219011/#msg219011 (https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick!/msg219011/#msg219011)
(https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick!/?action=dlattach;attach=44569;image)
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: AndrejaKo on September 01, 2013, 09:52:35 pm
I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.

Hmmm. I guess in order to try to replicate this, I'd need to to be able to play two different audio tracks at once, in sync, out two outputs, each connected to a channel on my scope. I'm not sure how to do this without some research first.... I could probably cheat and add a second audio card into my computer and I'm pretty sure I could sync play two tracks out two outputs under linux... definitely not sure how to do it under windows with the integrated audio (I have discrete outputs 1/8th" outputs, at least...).

-jbl

Since we're talking about X-Y mode, we're implying two channels, right(I hope I read your post correctly:))? It's been quite a while since I've heard of computer sound cards which are NOT at least stereo. Stereo=two channels in a single output!

As for synchronous playback, it's extremely easy! Just fire up Audacity (free and open source software, Google knows where to download it), go to file->import, select one audio file and import it. If it's stereo, click on the track, then go to tracks->stereo to mono.
Then import another sound file and it will show up as another track. Now comes the "tricky" part. On the left side of the track, you'll see a gray square. On it, you'll see information about track, like stereo or mono, sample rate, bit depth and so on. Just above sample rate, you'll see a black triangle pointing downwards. Click on it. Then you'll be able to select on which channel you want the track to play. Set one track to left, the other to right.



After that, get an audio cable with appropriate TRS jack at one side and remove the connector on the other side. Strip the insulation and you should have two signal wires and one or two ground wires. Connect them to your scope.

Then just click play button in Audacity and you'll have two different tracks playing synchronized at the same time. Total investment: Price of one stereo audio cable plus Internet bandwidth.
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 09:56:30 pm
I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.

Hmmm. I guess in order to try to replicate this, I'd need to to be able to play two different audio tracks at once, in sync, out two outputs, each connected to a channel on my scope. I'm not sure how to do this without some research first.... I could probably cheat and add a second audio card into my computer and I'm pretty sure I could sync play two tracks out two outputs under linux... definitely not sure how to do it under windows with the integrated audio (I have discrete outputs 1/8th" outputs, at least...).

-jbl

Since we're talking about X-Y mode, we're implying two channels, right(I hope I read your post correctly:))? It's been quite a while since I've heard of computer sound cards which are NOT at least stereo. Stereo=two channels in a single output!

As for synchronous playback, it's extremely easy! Just fire up Audacity (free and open source software, Google knows where to download it), go to file->import, select one audio file and import it. If it's stereo, click on the track, then go to tracks->stereo to mono.
Then import another sound file and it will show up as another track. Now comes the "tricky" part. On the left side of the track, you'll see a gray square. On it, you'll see information about track, like stereo or mono, sample rate, bit depth and so on. Just above sample rate, you'll see a black triangle pointing downwards. Click on it. Then you'll be able to select on which channel you want the track to play. Set one track to left, the other to right.



After that, get an audio cable with appropriate TRS jack at one side and remove the connector on the other side. Strip the insulation and you should have two signal wires and one or two ground wires. Connect them to your scope.

Then just click play button in Audacity and you'll have two different tracks playing synchronized at the same time. Total investment: Price of one stereo audio cable plus Internet bandwidth.

Ah.. Audacity. Alright. I'll see if I can scrounge up a 1/8th cable somewhere....

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 01, 2013, 11:33:53 pm
I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.

I'm going to have to see if I can somehow make this work on my tek 7603... I downloaded each of the two parts (black, white), loaded each into audacity, made one left channel, one right channel and cut the speakers off of some crappy in-hear headphones the kids had.

Connected that up to the Rigol playing off of my galaxy note 2 and...... well it doesn't come out all that well. I think if one could enable persist mode in x-y mode on the Rigol it might look better.. but it's more jumble than anything, unfortunately.

EDIT:

Looks like the 7D20 digitizer module for my 7603 has an X-Y mode... the result I get on the 7603 looks very similar to that of the rigol.. so I'm assuming I futzed something up in the conversion of the audio tracks OR the cable is attenuating or something...

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: dentaku on September 02, 2013, 12:10:46 am
I'm wondering why you bothered putting it into Audacity?
Just connect the audio cable into the headphone jack of the computer and play it in any audio player.
One wire goes to channel 1 the other wire to channel 2 and the loose copper wires surrounding them to ground.

I'd be interested in knowing what Nuclear Black Noise (that's part TWO not part ONE which is just noise) looks like on a digital scope http://jerobeamfenderson.net/nuclearnoise.php (http://jerobeamfenderson.net/nuclearnoise.php)
It works quite well even on my old B&K 1472C but I'm assuming it would also help to mess with the update rate on a digital one to get something like that to work well.

I'm going to have to see if I can somehow make this work on my tek 7603... I downloaded each of the two parts (black, white), loaded each into audacity, made one left channel, one right channel and cut the speakers off of some crappy in-hear headphones the kids had.

Connected that up to the Rigol playing off of my galaxy note 2 and...... well it doesn't come out all that well. I think if one could enable persist mode in x-y mode on the Rigol it might look better.. but it's more jumble than anything, unfortunately.

EDIT:

Looks like the 7D20 digitizer module for my 7603 has an X-Y mode... the result I get on the 7603 looks very similar to that of the rigol.. so I'm assuming I futzed something up in the conversion of the audio tracks OR the cable is attenuating or something...

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 02, 2013, 12:26:38 am
I'm wondering why you bothered putting it into Audacity?
Just connect the audio cable into the headphone jack of the computer and play it in any audio player.
One wire goes to channel 1 the other wire to channel 2 and the loose copper wires surrounding them to ground.

..snip..

Perhaps I misread the author's page... but I thought that the two files, Nuclear Black Noise and Nuclear White Noise, had to each get played to a separate channel simultaneously.

which suggests two sources playing simultaneously, one bought to left and the other right, no?

-jbl
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: IanB on September 02, 2013, 12:29:00 am
I downloaded each of the two parts (black, white), loaded each into audacity, made one left channel, one right channel

Why did you do that? The two parts (white, black) are separate and independent compositions, designed to be played individually just as on the original web page. Why would you think anything good happens if you try to play them both at the same time?
Title: Re: X/Y Mode on Digital Scopes? (Rigol DS2102)
Post by: jasonbrent on September 02, 2013, 12:33:10 am
I downloaded each of the two parts (black, white), loaded each into audacity, made one left channel, one right channel

Why did you do that? The two parts (white, black) are separate and independent compositions, designed to be played individually just as on the original web page. Why would you think anything good happens if you try to play them both at the same time?

Because I clearly misunderstood! I'll just try it again. :-)

-jbl