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

[BillyO]

If you think the added capacitance is small enough to distort the signal, repeat the test with the probe first at 1x, then at 10x.

Listen, go learn about transmission lines.  The generator WILL NOT see the scope capacitance at the other end of a properly terminated coax cable. 

My Siglent SDS2504X-P has an input capacitance of 17pF.  That's less than a cheap 100MHz probe set on 10X.  Set on 1X that would be more like 100pF.  You're talking utter nonsense.  I wouldn't be surprised if you thought the earth was flat too.

And I already told you, I'm injured.  Getting up and down the stairs is a big problem for me and I'm not going to do it right now for your sake.  I know exactly what I'll see.

[spikey1973]

In addition to trying to 'collect' functions that are not in the manual I bumped into the event counters and Freq counter under menu > disp (x1x10) > disp (x1x10).

But besides these two there is on mine also something called 20m for both Ch1 and Ch2. After activating it, it doesn't seem to do much more the showing 20m somewhere on the right side. Does anybody have any clue what this is all about?

Kind greatz

Matthieu.

[BillyO]

Does anybody have any clue what this is all about?

20MHz bandwidth limit.

[wilfred]

In addition to trying to 'collect' functions that are not in the manual I bumped into the event counters and Freq counter under menu > dev > dev.

But besides these two there is on mine also something called 20m for both Ch1 and Ch2. After activating it, it doesn't seem to do much more the showing 20m somewhere on the right side. Does anybody have any clue what this is all about?

Kind greatz

Matthieu.

I've been looking around at one of these portable type oscilloscopes lately. In one video I saw on YT it was attempted to measure 50MHz with the frequency counter added to the latest firmware (at the time the video was made) and the count was obviously wrong. It was clarified near the end of the video that the frequency counter was for 20MHz only. Although it seemed to top out on that unit in the mid 30's.

[BillyO]

No, for these two options it has to do with BW on the two channels, and nothing to do with the frequency counter.  I'm very familiar with the YT vid you mention.  However if you enable the "20m" option for either channel (or both) that channel will be limited to 20MHz BW.

[spikey1973]

@ all,

Thanks, that clarifies a bit indeed. guess the 20M is some sort of low-pass filter?
it draws out another question though, what is so specific about 20Mhz that it deserves such a settings.

Kind greatings

Matthieu

[Aldo22]

guess the 20M is some sort of low-pass filter?

Yes.

it draws out another question though, what is so specific about 20Mhz that it deserves such a settings.

Read here: https://www.eevblog.com/forum/beginners/the-popular-oscilloscope_s-20-mhz-bw-limit/

[taligentx]

Here's the FFT frequency measurement cursor added in the -III firmware:



(Edited this post as I initially thought it was a new feature in 3.0.6-III, but it's been available for -III hardware, just not called out in this thread).

[taligentx]

Current sale prices for one of the official Aliexpress storefronts (Zeeweii Factory Store):

https://www.aliexpress.com/item/3256805737614947.html

• US: $76.86 - $12 coupon = $64.86, plus local tax, free shipping (need to add some other items to reach the $89USD threshold for the coupon)
• EU: €91.99 - €12 coupon = €79.99, VAT included, free shipping

There are third-party sellers with lower prices but I figure it's more likely to get older hardware revisions that can't use the current firmware. Also, the coupon codes can go in and out of availability but the prices should be good until Dec 4.

[awakephd]

In addition to trying to 'collect' functions that are not in the manual I bumped into the event counters and Freq counter under menu > dev > dev.

How do I get to menu > dev > dev? (Not sure what key dev is, or what that means).

[BillyO]

In addition to trying to 'collect' functions that are not in the manual I bumped into the event counters and Freq counter under menu > dev > dev.

How do I get to menu > dev > dev? (Not sure what key dev is, or what that means).

It's "Menu > Disp > Disp"

The "Disp" key will be higlhighted once you hit "Menu", but its the "x1x10" key.

[awakephd]

Has anyone made a sort of reference list of the "not in manual, but still present functions for now?
seems like an interesting thing to me, so people don't figure things out by accident and then let the information evaporate into oblivion.
I am trying to make a list here for myself, but am very will to post it when done.

for now I have the following items: but please add if I missed something.
- Voice control (although this is discussable, as there is a manual with it in it)
- Shift + V/ch2 → persistend mode /phosphor emulation.
- enter FG via the "Gen" button, sine wave is limited to 5MHz, full-screen FG via the "Home" menu (short press the power button) the sine functions at 10MHz
- new frequency counter is good from 15Hz to 35MHz - well beyond specification.

I echo the desire for a comprehensive list!

[awakephd]

Got it, thanks!

[spikey1973]

It's "Menu > Disp > Disp"

The "Disp" key will be higlhighted once you hit "Menu", but its the "x1x10" key.

Indeed it is, sorry for this oepsie, I modified the post to make it clearer for future readers.

kind greats

Matthieu

[spikey1973]

I echo the desire for a comprehensive list!

Just let me know when anyone finds some new option and I will add it.

[taligentx]

Looking through @timschuerewegen's work decompiling and modifying the DSO2512G firmware, one of the improvements is the font:



Tim also provided the original and modified font data. I poked around the DSO3D12 3.0.5-III firmware and it uses identical font data, so it seems possible to mod this scope as well. The trick is that the newer Zeeweii scopes (DSO154pro, DSO3D12, DSO1C81) use an mcu with integrated flash (Winner Micro W806-C200), and I haven't found an easy way to dump the flash so currently only firmware provided by Zeeweii can be modded.

The W800 docs describe the firmware format - a .fls file with multiple images (bootloader, runtime image, etc), each with a separate header with checksums for the individual image and the header itself. It's possible to manually replace the data and calculate new checksums. Possible, but seems like a pain so...

Here's a tool to view .fls firmware header/image info, replace data with updated checksums, and extract images: https://github.com/taligentx/FLSTweak

I've added the font mod data to the examples directory, as well as a mod to fix the UI bug for the "Mea:" field label (it has an extra colon as circled in the screenshot above). The tool generates a new .fls file that can be flashed to the scope with this Windows tool or wm.py in the WM IoT SDK. Disclaimer: this is totally untested! My scope arrived with the newer 3.0.6-III firmware and I'll need to get a copy to test.

If you have a scope running 1.1.2 or 3.0.5-III and would like to try the updated UI, I can provide the steps or send a modded file. If there are any issues, it should be possible to flash the original firmware but needs testing.

I'm also interested in finding a way to dump the flash - the W80x series chips are also commonly used on smart home devices, etc. Would love to hear thoughts on ways to try this or general modding. For example, the W806 has six UARTs, it'd be interesting to see if any of them can be used to send data externally.

[taligentx]

Here's the output looking at v3.0.5:

Code: [Select]

$ ./flstweak.py dso3d12_v3.0.5_III.fls
Detected firmware type: W80x

Image 0:
  Image attributes:
    Type: Bootloader (0x0)
    Encryption: False
    Encryption private key #: 0
    Signature: False
    GZIP compression: False
    Block erase: False
    Always erase: False
    Compression type: 0
  Image address: 0x08002400
  Image size: 31580
  Header address: 0x08002000
  OTA update address: 0x08010000
  OTA update version: 0x00000000
  Version:
  Next image header address: 0x08010000
  Image checksum: 0x7C67C28A (verified)
  Header checksum: 0x2857E698 (verified)

Image 1:
  Image attributes:
    Type: User image (0x1)
    Encryption: False
    Encryption private key #: 0
    Signature: False
    GZIP compression: False
    Block erase: False
    Always erase: False
    Compression type: 0
  Image address: 0x08010400
  Image size: 417952
  Header address: 0x08010000
  OTA update address: 0x08010000
  OTA update version: 0x00000000
  Version:
  Next image header address: 0x00000000
  Image checksum: 0xD34FECFB (verified)
  Header checksum: 0x5325676A (verified)
Taking a look at image1 (the user runtime), there are also some typos for the calibration mode ("claib"):

Code: [Select]

Factory claib mode
Self-inspection
Claib: 100mV
Claib: temp
Claib: 1.0A
Claib: 100mA
Please restart!
 DCV = 5.000V
 Res = 100.0K
 DCA = 1.000A
 DCmA = 100.0mA
 Done!
Max 1000V
Max 600mV
Max 750V
Max 10A
Max 600mA
USB/DMM Conflict!
DC-1000V
DC-600mV
AC-750V
AC-600mV
DC-10A
DC-600mA
AC-10A
AC-600mA
DMM claib mode

And still present in 3.0.6:


Should be easy to fix these types of issues.

[taligentx]

Taking a closer look at the fonts - I found that ImageMagick works to convert the 1-bit font data for the small and large font:

Code: [Select]

$ magick -depth 1 -size 8x13 gray:zeeweii_font_small_ref.bin zeeweii_font_small_ref.bmp
$ magick -depth 1 -size 16x16 gray:zeeweii_font_large_ref.bin zeeweii_font_large_ref.bmpThis converts the raw font data to a series of bitmap files (should be a total of 95 files, covers ASCII characters 32-126).

Original Zeeweii (top) vs modified @timschuerewegen (bottom) - small font:


Large font:


The Zeeweii font has...issues. Even aside from the poor legibility, some characters like the curly braces {} in the large font are totally wrong.

As far as the scope itself, so far I've enjoyed using it! It came in handy to take a look at an LED strip power supply PWM and it correctly measured the duty cycle of the PWM down to the strips minimum at 10%. I have a couple of boat anchor Tek scopes but they're halfway around the world and don't have the measurements so this is a treat.

Edit: fixed the command for the large font, should be 16x16

[taligentx]

Success!



Instructions are on the repo - FLSTweak 1.0: https://github.com/taligentx/FLSTweak

[cte]

Just did the update procedure on my v3.0.5_III device and I'm now running v3.0.6_III with the better font. 

I had to run calibration after updating, but this worked without issues.

@taligentx: Thank you for the work! May I ask where you found the firmware v3.0.6_III for download? Zeeweii's website still shows v3.0.5_III.


And for the people running linux: The flash.py tool from the wm_iot_sdk needed some additional libraries. This should do the trick:

Code: [Select]

$ pip install colorama PyPrind pyserial serial xmodem
Verbose version info:

Code: [Select]

❯ python --version
Python 3.12.7
❯ pip freeze
colorama==0.4.6
future==1.0.0
iso8601==2.1.0
PyPrind==2.11.3
pyserial==3.5
PyYAML==6.0.2
serial==0.0.97
xmodem==0.4.7


[taligentx]

Great to hear! For the python dependencies, I've updated the flashing steps - the SDK actually includes requirements.txt with the necessary packages, so you can point pip to that file.

For the firmware, Zeeweii were kind enough to send via email - I have zero expectations of support for manufacturers that sell via Taobao/Aliexpress/etc so this was a pleasant surprise. That said, they may be waiting to see if there are any major bugs in the firmware before giving it a wider release on the support site. Or they just haven't bothered to update the site.

I had to run calibration after updating, but this worked without issues.

Can you elaborate on this? What was happening after the update?

I did notice that settings and saved waveforms remained even after flashing - the firmware is ~475kB out of the available 1MB so there's room for persistent storage. Also, it's clear that the saved waveforms are not screenshots/bitmaps - the scope is saving the data and re-rendering the display, because after flashing, all of the old saved waveforms were using the new fonts!

[cte]

I had to run calibration after updating, but this worked without issues.

Can you elaborate on this? What was happening after the update?

There was an significant offset. With the inputs left open, Ch1 was ~0.8 div above the GND marker.

[taligentx]

Update - FLSTweak 1.1: https://github.com/taligentx/FLSTweak

I rendered a new small font with all of the characters shifted down by 1 pixel. On the DSO3D12, the measurement labels each have a rounded background and the font from Tim was not centered. The DSO2512G doesn't have the background so the font alignment isn't as noticeable.
Before (left) vs after (right):


Working out how to render the font also means other font types can be swapped in if they look good at 8x13 and 10x16 pixels.

[motoge]

Hello everyone,
The +bandwidth setting is not displayed automatically．

Is there a different way to set it up?

[Medvidas]

@taligentx: Thank you for your modified FW. I am now on your 3.0.6-III mod and it looks much better. It should be part of the original firmware, maybee Zeeweii can be open to incorporate your mod into the master FW. I kind of dream that one day they will share the source code and let the community tweak the device in their own image. Then they could sell zillions of devices and everyone would be happy. 

You make good point with the View gallery, the images are re-rendered in new fonts. If scope really keeps the source data, then it's a pity that zooming and cursor operations are not implemented in the gallery.

And the last thing I haven't seen described anywhere and discovered while working with the gallery of saved images - pressing x1x10 works as a delete button!