Siglent STB3 Demo board - Noisy Sine Wave..

[simmiv]

Hi,
I'm playing with my SDS1204X HD oscilloscope using the Siglent STB3 Demo board.. 
The first waveform to look at is a 25MHz Sine Wave on pin header J18 on the right side of the board with ground reference being J34.
I've set up the scope as per the manual, which works fine.
However, I think the Sine Wave is a bit noisy and jittery.  This could be perfectly normal, but just in case I would appreciate if someone with an STB3 board has a look at theirs and can confirm my observation.
Showing photos won't show the noisy jump of the Sinewave, so I have put together a short video clilp to demonstrate what I'm seeing.

The video clip has the following:

• Picture from the STB3 Demo board manual showing the 25MHz Sine Wave. You can see what scope settings they used.
• Picture of my setup.  I'm powering the STB3 board via a USB Power adapter.   I've tried using a battery pack to power it in order to eliminate any ripple from the power adapter.  That produces the same results.
  
• A closeup of my scope and my settings for the Sine Wave..
• A short video clip of the Sine Wave with my settings.  Note the noise on the wave..
• A short video clip with a closeup of the Sine Wave..
• A short video of an FFT for the Sine Wave just for fun..  It seems to have a fair few harmonics..

Youtube clip is here: https://youtu.be/CVz_BeiQMiU

As I said, this could be perfectly normal for these boards, however if others see the same or similar thing, I'm not going to worry about it..

**************************
On a side note, I use Bitdefender Antivirus and Firewall Software like many others.  Sadly, Bitdefender disrupts the connection from browsers to the scope when trying to view the scope over the LAN.  It doesn't matter if you use the Bitdefender control panel to turn off all it's functionality.  You have to remove it from the computer and then reboot.  Then the VNC connection from the browsers works fine.  The simple workaround is to use a VNC viewer, or view the scope from a tablet or mobile phone.  That works fine.  I've downloaded a couple of VNC viewers and both work fine with Bitdefender installed and in it's normal configuration..

Rgds,
Simmi

[Martin72]

Hi,

I'm going to try this with my STB-3 and 3104X HD.

Small note:

I've tried using a battery pack to power it in order to eliminate any ripple from the power adapter.  That produces the same results.

Unless they are “pure” batteries, such a pack will also have ripple because of the step-up converter to turn e.g. 3.7V into 5V.

[Martin72]

Same here....

(Note: 30fps)

[simmiv]

Great!  I suspected as much! 
Looks like my board should be ok then.. 
Thanks for taking the time to do this!  Much appreciated..
Rgds,
Simmi

[Martin72]

Now you can do me a favour with the STB-3...
I²C Decoding...in ASCII....
Please show me the result (screenshot)...

[tautech]

Some STB-3 signals are intentionally noisy so to have the user apply the various scope features to 'clean' the signal, eg. Trigger filters, ERES etc.

If we look at Stats in the OP's video it is obvious Freq Std Dev of 31Hz is responsible for the instability.

STB-3 manual needs updated screenshots to come into line with the current display seen in the modern models.
https://int.siglent.com/u_file/document/STB3_UserManual_UM60109_E01A.pdf

[simmiv]

I did an IC2 decode off the board and thought I'd done some misstakes as I wasn't getting SIGLENTxxxx!!
I've now realized that I'm getting the same as others i.e. the first five letters are missing! 
I'm in Australia and had to wait for the board arrive into the country from Siglent.  I just got it, so it's supposed to be brand new!
My screenshot below..

[tautech]

Hmmm, the bits are there but I suggest Decode trigger settings are not right.

Try just a falling edge trigger and one packet width of Holdoff.

Edit to add screenshot

[simmiv]

Thanks,
But that looks like SPI decode..   The one I have is the I2C decode, which seems to have lost the first five characters in the STB-3 Demo board.. 
I wonder if Siglient knows about this or is this a firmware issue/error?  I'm not the only one with an STB3 board with this issue..   Some of the older boards, i.e. people who have had theirs for a long time report them being ok..  Not sure when this crept into production?
Rgds,
Simmi

[tautech]

Thanks,
But that looks like SPI decode..   The one I have is the I2C decode, which seems to have lost the first five characters in the STB-3 Demo board.. 
I wonder if Siglient knows about this or is this a firmware issue/error?  I'm not the only one with an STB3 board with this issue..   Some of the older boards, i.e. people who have had theirs for a long time report them being ok..  Not sure when this crept into production?
Rgds,
Simmi

Gimme a tick and I'll provide a I2C screenshot....

Yep, Siglent at high levels are aware some STB-3 have issues and we have asked for a firmware flash to rectify them.
Mine is a very early unit, near 10yrs old now but if necessary we'll push HQ again for some action as all we have had thus far is crickets. 

Edit to add screenshots.

[simmiv]

That is good info..
I hope they fix this, otherwise it's grounds for returning the product and get a refund..   
Don't see why they can't fix up the firmware and provide..  Unless they want to do a product recall for defects!
Rdgs,
Simmi

[KungFuJosh]

I hope they fix this, otherwise it's grounds for returning the product and get a refund..   

If you do return it, the Batronix MSO demo board is excellent.

[Martin72]

Don't see why they can't fix up the firmware and provide..

First of all, thanks for trying it out, so there are now three of us with regard to the faulty I²C signal.
But this is also the “problem” as to why no new firmware is available yet.
In terms of priority, this should be pretty much at the bottom end, for which I can even understand.
Apart from that, simply installing a new firmware will not work, it will not work via USB, but if directly, with a programmer.
The “original” file would be enough for me for the time being, it may be enough to reprogram the chip again.
Hello Rob...

[tautech]

Don't see why they can't fix up the firmware and provide..

First of all, thanks for trying it out, so there are now three of us with regard to the faulty I²C signal.
But this is also the “problem” as to why no new firmware is available yet.
In terms of priority, this should be pretty much at the bottom end, for which I can even understand.
Apart from that, simply installing a new firmware will not work, it will not work via USB, but if directly, with a programmer.
The “original” file would be enough for me for the time being, it may be enough to reprogram the chip again.
Hello Rob...

Waves.....

Actually Defpom has STB-3 and knows how to sniff stuff.......I'll see if he has time to do us a favor.....

[TheDefpom]

You give me too much credit Rob, it is an Altera MAX 10 FPGA, not something I have any knowledge about, the clock and data lines go directly to the FPGA so whatever is happening relates to that device, something I expect most of you would have already known anyway.

The FPGA used is the C8 variant, the slowest one... maybe it is too slow ? https://www.intel.com/content/www/us/en/docs/programmable/683794/current/fpga-device-datasheet.html

[tautech]

You give me too much credit Rob, it is an Altera MAX 10 FPGA, not something I have any knowledge about, the clock and data lines go directly to the FPGA so whatever is happening relates to that device, something I expect most of you would have already known anyway.

The FPGA used is the C8 variant, the slowest one... maybe it is too slow ? https://www.intel.com/content/www/us/en/docs/programmable/683794/current/fpga-device-datasheet.html

Picked up on this again with HQ and you might remember the good work you did for us a while back on this issue.
https://www.eevblog.com/forum/testgear/siglent-sds2000x-plus-coming/msg5029306/#msg5029306

Let's see what they can put together for the few that have these STB-3 I2C issues.
 

[InvisibleMan]

To add another data point re the I2C decode issues:

I have board no.38 (Serial JXX170227GAA0038RoHS) and mine is ok with I2C
Gathering data from the other STB-3 threads it looks like this I think:

Board no
10 (tautech) = ok
38 (mine) = ok
146 (Mathstudi) = problem
248 (Martin72) = problem

So it looks like something changed between boards 38 and 146?

[Kean]

I have board no.38 (Serial JXX170227GAA0038RoHS) and mine is ok with I2C

Those are likely only a sequential number in a production batch.
e.g. the serial number in Defpom's video linked above is MK160803BAA0093 - which I'd guess is an earlier batch than the ones beginning JXX170227

As these are targetted to education, I'd expect they have made many more than a few hundred units.

Edit: I see in Simmi's video his seems to start with JXX170227 - but it isn't quite clear and partly obscured by a cable.

Edit 2: OK, I see more serial data in that year old discussion and all but Defpoms seem to begin with JXX170227