Another DSO+DMM - Zeeweii DSO3D12, claimed 120MHz/250MSps (june 2023)

[dietert1]

I'd guess the trigger is derived from digitized input and for power saving (battery live) there is no full rate sampling with decimation. So trigger will depend on sampling rate. If you know your instrument, you can work around this.

Regards, Dieter

[Fungus]

If I zoom in, the signal is triggered.
Will investigate this some more.

The signal is always triggered, you just can't see the signal.

This sort of signal is why some 'scopes have a "peak detect" mode.

[RAPo]

Maybe,
I did some further research (this time with Juntek PSG9080):

DC 2.10% display is okay at 10ms.
DC 2.00% display is not stable triggered at 10ms.
DC 1.99% a slight running black peak in the screen at 10ms
DC 1.98% the flip-flopping occurs at 10ms
From 5ms and lower, no flip-flopping.
See the photo for the 1% peaks.
From 5ms and lower, you can count the peaks easily. At 10ms, it is unworkable.

Maybe that's not such a bad thing.
The Zeeweii tells you this way that the resolution is not enough to display the signal reasonably.
Whatever it shows (all yellow, all transparent, what do you expect it to show?) it's wrong anyway ;-)

Just the screen alone: How many 1% peaks can you adequately display with 360 pixels?

My 2 ¢

[Fungus]

Maybe,
I did some further research (this time with Juntek PSG9080):

DC 2.10% display is okay at 10ms.
DC 2.00% display is not stable triggered at 10ms.
DC 1.99% a slight running black peak in the screen at 10ms
DC 1.98% the flip-flopping occurs at 10ms
From 5ms and lower, no flip-flopping.
See the photo for the 1% peaks.
From 5ms and lower, you can count the peaks easily. At 10ms, it is unworkable.

Sounds about right.

[RAPo]

I meant stable triggered:
It would be great if these scopes had other trigger types than edge-trigger.

The signal is always triggered, you just can't see the signal.

This sort of signal is why some 'scopes have a "peak detect" mode.

[RAPo]

yes, but I would like to have some more control upfront.

I'd guess the trigger is derived from digitized input and for power saving (battery live) there is no full rate sampling with decimation. So trigger will depend on sampling rate. If you know your instrument, you can work around this.

Regards, Dieter

[ptluis]

Strange triggering.
I'm applying a 1kHz square wave with a 1% duty cycle (from the Fnirsi DPOX) and zooming out to 10ms.
A block of square waves randomly flops from right to left on the screen.

You try to replicate on the dso2512g and you will see something interesting  it flickers/disappear... I tried with a utg962 FG. could this be related to the low memory of the device ? low sample rate?

[Fungus]

could this be related to the low memory of the device ? low sample rate?

Just very narrow pulses on screen and no "peak detect" mode to display them.

Zoom in a bit and you'll see them just fine.

[ptluis]

could this be related to the low memory of the device ? low sample rate?

Just very narrow pulses on screen and no "peak detect" mode to display them.

Zoom in a bit and you'll see them just fine.

at 5ms and bellow work fine, 10ms and above strange things happen on display.

[ptluis]

Strange triggering.
I'm applying a 1kHz square wave with a 1% duty cycle (from the Fnirsi DPOX) and zooming out to 10ms.
A block of square waves randomly flops from right to left on the screen.

Hi RAPo, did you try doing this on dpox180h? I wonder how it behaves, just curious.

[Fungus]

Hi RAPo, did you try doing this on dpox180h? I wonder how it behaves, just curious.

ANY DSO will do this if it isn't set to peak detect mode (assuming it has one).

(...or some variant of this)

[RAPo]

Just did.

1kHz from PSG9080 on the DPOX gives:
Duty cycle 2% no flip-flopping, freq measure alternates between 44.73Hz and 45.13Hz (no kHz!)  and DC=2.66% at 10ms.
Duty cycle 1% no flip-flopping, freq measure alternates between 38.35Hz and 39.15Hz (no kHz!)  and DC=1.25% at 10ms.

You can count individual pulses from 5ms onwards.

[RAPo]

Got a message from Zeeweii:

Thanks for your suggestion, I have given feedback to the engineer.

Got a message from Zeeweii:

DSO3D12 does not support transferring images to PC.

I asked to add this in a firmware update.

[ptluis]

could this be related to the low memory of the device ? low sample rate?

Just very narrow pulses on screen and no "peak detect" mode to display them.

Zoom in a bit and you'll see them just fine.

At 5ms displays just fine. Sometimes my brain gets dump  ... How did I forgot about peak trigger  ... of course these cheap devices like dso2512g and dpox180h are very limited in trigger options, and that's one of my suggestions to zeeweii, to add more trigger options.

[ptluis]

I asked to add this in a firmware update.

The engineer will have a lot to do in the near future, 16 suggestions including bugs in dso2512g, plus those in DSO3D12... the next firmware will be released in 2024-5 or in the form of a new device 
 
These low-priced products are sold in parts. Each new product includes one or two new to the market features. After we buy it, we see that important features are missing, so we require to add and improve the device. Then they launch a new device with 1 or 2 new features + 1 or 2 of the requested ones and off we go to buy another one... This is how several versions of the device are launched. In the end we just have to put them together on the table to have a complete device, like a puzzle.

My friend we are in the same struggle 

[Fungus]

The engineer will have a lot to do in the near future, 16 suggestions including bugs in dso2512g, plus those in DSO3D12... the next firmware will be released in 2024-5 or in the form of a new device 

I think they should open-source these, that way they can concentrate on making hardware (which is probably what they enjoy most).

They sell the next generation by upgrading the bandwidth or the ADC or the FPGA or the memory...

I guess they're scared that other companies could clone the hardware and then they make nothing. I don't really see how they could undercut them though and plenty of people would want "originals" even if they cost 10 bucks more (I would...)

If they're releasing the next generation they'll always be a few months ahead of the cloners anyway. The important thing is to establish the Zeeweii brand.   

[ptluis]

The engineer will have a lot to do in the near future, 16 suggestions including bugs in dso2512g, plus those in DSO3D12... the next firmware will be released in 2024-5 or in the form of a new device 

I think they should open-source these, that way they can concentrate on making hardware (which is probably what they enjoy most).

They sell the next generation by upgrading the bandwidth or the ADC or the FPGA or the memory...

I guess they're scared that other companies could clone the hardware and then they make nothing. I don't really see how they could undercut them though and plenty of people would want "originals" even if they cost 10 bucks more (I would...)

If they're releasing the next generation they'll always be a few months ahead of the cloners anyway. The important thing is to establish the Zeeweii brand.   

the firmware update of the dso2512g is based on the dso1511g firmware,  there's references inside the file, so they keep releasing new devices with peaces of the puzzle. maybe it could be possible to reverse engineer this firmware. the problem here could be the fact that exists at least 3 base firmware versions, each for different hardware revisions, and creating a custom firmware could not be a simple task. maybe yes maybe no, I'm no expert.

[Fungus]

the firmware update of the dso2512g is based on the dso1511g firmware,  there's references inside the file

Obviously there's going to be a lot of common code.

creating a custom firmware could not be a simple task. maybe yes maybe no, I'm no expert.

It's not trivial but a lot of progress has been made on other devices:
https://www.eevblog.com/forum/projects/reverse-engineering-fnirsi-5012h/
https://www.eevblog.com/forum/testgear/fnirsi-1013d-100mhz-tablet-oscilloscope/1400/

[wasedadoc]

Some info on the DSO3D12 FFT which is not in the manual.  I have derived this by experimental observation.  Maybe also applicable to the DSO2512G?

1.  In all three modes the frequency axis (horizontal) is linear and ranges from 0 at the left to a frequency determined by the
timebase setting.  That frequency is 25 divided by the time per division and holds for all timebase settings not faster than 500ns
per division.  So the extremes are 10s per division which makes the range 0 to 2.5Hz and 500ns which makes the range 0 to 50MHz.
Selecting 1ms/div gives 0 to 25kHz which may be appropriate for audio.

2.  In the music mode, the amplitude response (Y axis) is linear.

3.  In log(arithmic) mode the vertical axis is NOT 10db/div.  Looks like each division corresponds to a factor of 8 times larger or
smaller.  (Maybe some simple mapping from the binary numbers.)  The absolute levels are related to the Volts/div setting in a simple
manner.  The penultimate line from the top is reached when the RMS value of the input sine wave component at that frequency is equal to the Volts/div setting. For example, if the input is 200mV RMS and the sensitivity is 200mV/div the spectral line will reach the
horizontal line below the top one.

[shakalnokturn]

Just sold my Hantek 2D42 pocket/toy scope, it was handy for basic field work, screen was a little small to my liking but mainly the UI for getting around the scope adjustments was so counter intuitive it drove me nuts.

Looking at the chart here:
https://www.eevblog.com/forum/testgear/portable-oscilloscopes-list/msg5194335/

It seems the Zeeweii DSO3D12 would suit me better for screen size and UI, at least they have separate Volts & time / div. keys which make more sense to me than general purpose direction keys.
I don't think much of the AWG (although I don't care for that much) or overall build quality compared to the Hantek or Owon HDS, it clearly looks more of a toy.

Could any owners out here who would willingly admit it if they consider they've wasted money give me their overall impressions.

[wasedadoc]

Just sold my Hantek 2D42 pocket/toy scope, it was handy for basic field work, screen was a little small to my liking but mainly the UI for getting around the scope adjustments was so counter intuitive it drove me nuts.

Looking at the chart here:
https://www.eevblog.com/forum/testgear/portable-oscilloscopes-list/msg5194335/

It seems the Zeeweii DSO3D12 would suit me better for screen size and UI, at least they have separate Volts & time / div. keys which make more sense to me than general purpose direction keys.
I don't think much of the AWG (although I don't care for that much) or overall build quality compared to the Hantek or Owon HDS, it clearly looks more of a toy.

Could any owners out here who would willingly admit it if they consider they've wasted money give me their overall impressions.

I bought one for the occasions when I don't need, and cannot be bothered to unbox and fire up, my Rigol DS1054Z.  I don't regret buying it and haven't come across any serious bugs.  I have no complaints about the build quality. Some slight negatives are:

1.  Although dual channel, there are no math functions, not even CH1 minus CH2.

2.  Like most of these small 'scopes the triggering options are very limited.  Basically rising or falling edge and adjustable level.

3.  Dual channel mode does not appear to compensate for the interleaved sampling.  If you put the same input into both channels the traces are separated by a few nanoseconds.  Not a big problem if you are aware of it.

4.  I have not found the voice command feature to be particularly useful.  IMHO would have been better to have spoken output of the multimeter readings.

There is quite a good review at

and a second part at

Some instructions at

[flywheelz]

shakalnokturn
have you seen Zoyi ZT703s, also 3.5" screen 2ch?

[shakalnokturn]

Thanks to wasedadoc for the review links, they were useful.
Thanks to flywheelz for pointing me to the Zoyi toy, it looks quite good unfortunately AFAICT it has the typical direction keys UI that I'd like to avoid. Flipping around menus for changing the most frequently used settings just doesn't make sense to me. If I see one going really cheap I'll give it a try though...

[jdev99]

I fitted a SMA connector to the side of the back cover, for the sig.gen output.
Works much better then the 2 prongs on the top. Also made sure it does not interfere with anything on the inside.
The SMA connector is designed for at least 12GHz and  50 Ω impedance, so should be OK for this application.
Yes, it should have been a female connector, but I only had a male around.    

[Evi]

Voice Assistant built around Unisound US665P31 processor and OPA62.
Allmost no info except a couple of words about similar system:
https://www.hackster.io/news/icstation-s-5-su-10a-packs-an-on-board-unisound-us516p6-for-offline-voice-recognition-work-680799a416e7