New Zoyi multimeter+oscilloscopes - ZT-70xS, up to 50MHz/250MSps (nov 2022)

[Aldo22]

Edit:  From the specs it appears the Zeeweii is a better scope.  The Zoyi is the better DMM.  Again, from the specs.  I've not tested the two in practice yet...

Exactly!
In my opinion, even the cheapest Zeeweii oscilloscope is better than this Zoyi, from what I've read.
https://www.aliexpress.com/item/1005007394192248.html

But Zotek makes very good cheap DMMs. I love my ZT-225.

[IC_Toaster]

This device is made according to the ARM+ADC scheme, whereas most other manufacturers use the FPGA+ARM+ADC scheme. Therefore, this device does not work well. And the new firmware won't do anything.

Exactly.

It could be made better, but it will never be a proper oscilloscope.

The only question is, it worth the time, to make a proper firmware for this device, or just wait for a scopemeter with at least an FPGA in it 

Making a proper firmware sounds interesting, but if there are not expectations of getting a good working, it doesn't worth it. I don't have enought knowledge to help you in it.

[ajar171]

It is a real shame, how they made this scopemeter. I really like the size and the UI concept, but it is unusable for my purpose.

If they would at least made a simple analog trigger circuit, it would only have costed them a few cents and I would be happy to pay more for a functioning trigger. There is enough room left on the PCB, and the MCU also hase enough unused DACs to set the trigger level. Even with an analog trigger, this would be a usable scope with some firmware tricks, altough even that would not give us a proper single mode trigger.

I have ordered myself an Owon HDS scope, because I need a proper single mode trigger. The saying is true: buy cheap, buy twice...

Edit: found it, a real analog trigger, at least for channel 1. I think I have to reverse the analog frontend to see, what they have built.
If the TFT supports auto-refresh, then a working single mode trigger is possible (at least on channel 1)

[ajar171]

Update:

pinout of the MCU almost completely mapped (only 6 pins left)

I have to decode the communication between MCU and DMM chip.

Both channels have a basic analog trigger.

[Atlan]

Will the complete scheme with the entrance part be redrawn?

[ajar171]

It will have to be at least partly reversed. I think there is no need the redraw the DMM schematic, as it simply works and only communicates with the main MCU via UART

Maybe someone in the thread will be kind enough to reverse the analog frontend of the scope part, as I am still looking for the remaining MCU connections and decoding the communication to the DMM chip.

Also my backlight driver chip died (my mistake), so will need to look for a replacemant chip 

[ajar171]

A summary about the Zoyi ZT-703S:

- dual channel 100MSPS ADC (overclocked to 140MSPS in high speed mode), both channels sampled in parallel
- analog comparators as trigger for both channels (trigger level adjustement with DAC1_OUT1)
- external flash connected to SPI4, only used for screenshot storage
- DMM chip connected via UART5, 9600-8-N-1, 18 byte packets to the MCU
- LCD with 20MHz pixel clock, RGB565, DE mode, no HSYNC or VSYNC used. No SPI connection.
- Signal genarator uses the 1MSPS 12bit DAC, at 50kHz output only 20 DAC points/cycle

All the pins of the MCU and the HC595 found 

Goals for an open source firmware:
DMM:
- recreate original functionality <- communication decoded
- switchable analog scale
- add CSV logging
- add graph history
- add CDC to the USB mode for remote control of the DMM

Scope:
- no overclocking
- proper triggering
- user control of sampling speed, memory depth
- equivalent sampling for repeating signals
- voltage calibration

Signal generator (do we really need this...):
- user stored waveforms in addition to the standard ones

There is one big IF for a properly working firmware, that is auto-refresh of the LCD. The LCD controller uses DMA and the main RAM for framebuffer, but we need these resources while doing high speed sampling. Here is where the missing FPGA would help...

I will use this post as a main place for updates.

[indman]

Goals for an open source firmware:
DMM:
- recreate original functionality
- no analog scale

Even though the analog scale does work and is slow to update, I think it is needed and gives a vintage look to the DMM interface. The only nuance that I would change is to slightly increase the size of the numbers on the display, if of course this is possible. I bought the ZT-703 mainly because I really liked the DMM interface and how it worked.

[IC_Toaster]

A summary about the Zoyi ZT-703S:

- dual channel 100MSPS ADC (overclocked to 140MSPS in high speed mode), both channels sampled in parallel
- analog comparators as trigger for both channels (trigger level adjustement with DAC1_OUT1)
- external flash connected to SPI4, only used for screenshot storage
- DMM chip connected via UART5, 9600-8-N-1, 18 byte packets to the MCU
- LCD with 20MHz pixel clock, RGB565, DE mode, no HSYNC or VSYNC used. No SPI connection.
- Signal genarator uses the 1MSPS 12bit DAC, at 50kHz output only 20 DAC points/cycle

Goals for an open source firmware:
DMM:
- recreate original functionality
- no analog scale
- add CSV logging
- add graph history

Scope:
- no overclocking
- proper triggering
- user control of sampling speed, memory depth
- equivalent sampling for repeating signals

Signal generator (do we really need this...):
- user stored waveforms in addition to the standard ones

There is one big IF for a properly working firmware, that is auto-refresh of the LCD. The LCD controller uses DMA and the main RAM for framebuffer, but we need these resources while doing high speed sampling. Here is where the missing FPGA would help...

I would add, for the scope part, a right voltage measurement. I think my device measures around 0,2 V less than the real value.

[ajar171]

Even though the analog scale does work and is slow to update, I think it is needed and gives a vintage look to the DMM interface. The only nuance that I would change is to slightly increase the size of the numbers on the display, if of course this is possible. I bought the ZT-703 mainly because I really liked the DMM interface and how it worked.

I would add, for the scope part, a right voltage measurement. I think my device measures around 0,2 V less than the real value.

Added to the list

[spikey1973]

You were looking poorly or in the wrong place. Here is the link on page 20 of this topic
https://www.eevblog.com/forum/testgear/new-zoyi-multimeteroscilloscopes-zt-70xs-up-to-50mhz250msps-(nov-2022)/msg5585305/#msg5585305

guess I was looking poorly then, I searched for the specific FW numbers like 1.32 and 1.3.2 and firmware and FW but this was not in the post itsef so I looked over it.
but thank you for pointing me to it and @kamil004 thank you for putting that here !

@ajar171
thank you for all the effort you are putting in

[spikey1973]

I found this, it seems a firmware bug. Press “Default" and confirm, it will close the signal-generator output.

@ Suntide, i am ot sure what you mean with the "default", and in which menu? F1 or F4 (I didn't find them in both and basically triedd out all the buttons.

ps: I am on FW 1.3.2 now.

kind greats

Matthieu

[Astur_TorQue]

A summary about the Zoyi ZT-703S:

- dual channel 100MSPS ADC (overclocked to 140MSPS in high speed mode), both channels sampled in parallel
- analog comparators as trigger for both channels (trigger level adjustement with DAC1_OUT1)
- external flash connected to SPI4, only used for screenshot storage
- DMM chip connected via UART5, 9600-8-N-1, 18 byte packets to the MCU
- LCD with 20MHz pixel clock, RGB565, DE mode, no HSYNC or VSYNC used. No SPI connection.
- Signal genarator uses the 1MSPS 12bit DAC, at 50kHz output only 20 DAC points/cycle

All the pins of the MCU and the HC595 found 

Goals for an open source firmware:
DMM:
- recreate original functionality <- communication decoded
- switchable analog scale
- add CSV logging
- add graph history

Scope:
- no overclocking
- proper triggering
- user control of sampling speed, memory depth
- equivalent sampling for repeating signals
- voltage calibration

Signal generator (do we really need this...):
- user stored waveforms in addition to the standard ones

There is one big IF for a properly working firmware, that is auto-refresh of the LCD. The LCD controller uses DMA and the main RAM for framebuffer, but we need these resources while doing high speed sampling. Here is where the missing FPGA would help...

I will use this post as a main place for updates.

It will be extremely great if you  manage to create an open source firmware! You are cracks!

Also:

Multimeter mode:
-Remove that fucking needle XD

[ajar171]

It would really help a lot, if someone would reverse the analog frontend of the scope part!
Only the part below the shielding cans up to the inputs of the ADC have to be redrawn, I have already found everything connected to the two HC595s, and the digital signals of the ADC are also done.

 

[lchao]

Latest FW is 1.42

I have installed the latest version of the software.
(Attachment Link)
But I wouldn't say that anything has changed much.
(Attachment Link) (Attachment Link)

It seems on the attached picture that the graph is showing the correct value: 2 divisons and 1 point on a 5V division setting is roughly 12V. So "only" the indicated min and max value seems to be wrong.
As far as I remember similar curve vs. displayed value issue was already mentioned earlier in this forum.

[chebo]

Latest FW is 1.42

I have installed the latest version of the software.
(Attachment Link)
But I wouldn't say that anything has changed much.
(Attachment Link) (Attachment Link)

It seems on the attached picture that the graph is showing the correct value: 2 divisons and 1 point on a 5V division setting is roughly 12V. So "only" the indicated min and max value seems to be wrong.
As far as I remember similar curve vs. displayed value issue was already mentioned earlier in this forum.

Yes, that's exactly what I was paying attention to - the discrepancy between the values ​​of the displayed curve. And they still haven't fixed it.

[LucSVK]

Hello Guys, sorry to disrupt your thread.
Would you recommend this one ( Zoyi ZT 703S ) or similarly priced FNIRSI 2C53T - 50Mhz, FPGA ? As a beginner I am currently in a process of buying my first  multimeter with oscilloscope capability/oscilloscope with DMM capability. I have just ordered Zoyi, but when it arrives I have 15 days to return it.

Please, does Zoyi have a big disadvantage because of the FPGA absence?
In datasheet I can see that FNIRSI has less accurate DMM.  But otherwise, I am not so experienced so I have difficulty to decide which one to buy.

Btw your effort to create OSS FW for Zoyi is great! If I had more experiences, I would definitely participate and help you with this.

Thanks a lot for your help!

[ajar171]

The chinese low budget test equipment manufacturers are quick to abandod their products, but Fnirsi is extremely fast in that regard. Zoyi already released at least 7 updates (what I know of), which can not be told about the Fnirsi products I own...

The 2C35T has the same oscilloscope (and signal generator) specs as the 703, so probably the same hardware, I can not imagine, that there is an FPGA in that meter. The UI is different, so you have to choose, what you like more, there are enough videos on youtube about both meters. IMO they are the same apart from the DMM and UI part.

I will for sure make the OSS UI similar to the Zoyi one, since I like it

[spikey1973]

@LucSVK

Hello Guys, sorry to disrupt your thread.
Would you recommend this one ( Zoyi ZT 703S ) or similarly priced FNIRSI 2C53T - 50Mhz, FPGA ? As a beginner I am currently in a process of buying my first  multimeter with oscilloscope capability/oscilloscope with DMM capability. I have just ordered Zoyi, but when it arrives I have 15 days to return it.

Please, does Zoyi have a big disadvantage because of the FPGA absence?
In datasheet I can see that FNIRSI has less accurate DMM.  But otherwise, I am not so experienced so I have difficulty to decide which one to buy.

Btw your effort to create OSS FW for Zoyi is great! If I had more experiences, I would definitely participate and help you with this.

Thanks a lot for your help!

Hey, I Have (very) recently been in your shoes!
Although I myself really dislike it when someone goes outside the offered choise option I would really suggest an
third option. the Zeeweeii DSO3D12.

I have bought the Zoyt/Aneng 703 but was very disappointed in the machine as most of the people here.
I am a beginner, just like you and found it is, besides the known bugs, really not inuitive.
Most of the issues are software based, hence the attempts to make an new FW version, which I personally are really looking forward too,

Anyway, untill this project is an reality, I personally prefer the zeeweeii.
have a look at this thread:
https://www.eevblog.com/forum/testgear/another-dsodmm-zeeweii-dso3d12-claimed-120mhz250msps/

additionally, the 15 days return option, sounds very familiar, adn let me warn you. I tried to make use of this option and the seller did not accept..
I only got a partial refund, but didn't need to ship the 703 back. And I assume this is an common issue with the seller.
Most likely as they know a lot of people are dissatisfied and want to return it, so they stopped accepting.

So if they haven't shipped out yet, cancel the order now, and take your time to re-consider. between the 3 models.
ps: i know the zeeweeii doesn't look very nice compared the other two, but it works quite well.
I am not knowledged about the FNIRSI, but it never really drew my attention, but never really heard good reviews on it. did see that people are also working on a new FW for it predecessor so, to me that doesn't sound well.

Anyway, good luck with you choice.

Matthieu



 

[ajar171]

Exactly.

The Zoyi and the Fnirsi are IMO the same hardware. They are both software only oscilloscopes, and the lack of a proper hardware can not be compensated in software.

The OSS FW idea for the Zoyi is a just fun project for me, hopefully there will be some collaboration too, but don't expect functionality (and speed) like in scope with proper hardware.  I just want to get the most from the hardware I bought and have some fun

There are affordable scopes from Siglent or Rigol or a used scope from a more prestigous brand, that are not riddled with bugs in basic stuff like triggering. If you are a beginner, do yourself a favor, and buy a proper (even used) scope from a know good brand, so you will not be confused with buggy firmware.

Edit: Just checked, the 1054Z (hackabale to 100MHz) costs 343€ with 3 years of warranty, and free delivery in the EU. 4 channels, 1Gsps. 

[Astur_TorQue]

It would really help a lot, if someone would reverse the analog frontend of the scope part!
Only the part below the shielding cans up to the inputs of the ADC have to be redrawn, I have already found everything connected to the two HC595s, and the digital signals of the ADC are also done.

 

I wish I had the knoledge to help in something

[LucSVK]

Hi Ajar171, no the FNIRSI really has the FPGA.
Vendor promotes this on their website.

https://www.fnirsi.com/products/2c53t

✦ Excellent Design: The Oscilloscope adopts FPGA + MCU + ADC hardware architecture, built-in high-voltage protection module, adopts 2.8 inch LCD display, built-in 3000mAh Li-ion battery, standby time up to 6H, Type-C interface supports 5V/1A charging.

AFAIK it has the same HW inside as Fnirsi 2C53P in the package of the old 2c23T
For example FPGA should be GOWIN Semiconductor GW1N-UV2

It has nothing in common with Zoyi. It should be able to do 50Mhz on both channels simultaneously.

Thanks

---

Hey spikey1973

I will have a look at Zeeweeii DSO3D12. I briefly checked information on their site and it's 120Mhz 1CH, 60Mhz 2CH. So is it similar architecture like Zoyi?  ( SW based?)

About the free return. Unfortunately it's on the way already. I bought it 2 -3 days ago from the Official Zoyi store on Aliexpress.

Aliexpress says:

You have 15 days from receiving the item(s) to return your order without explanation as long as:
- All items are in perfect condition and in the original packaging.
- Any safety seals are not damaged and all labels are retained.

Open a dispute within 15 days of receiving the order
Print a Free Return label
Go to the designated return point
Wait for your refund

https://sale.aliexpress.com/__pc/1BB5HiMxKx.htm

Did you open the dispute when you tried to return yours?
How much they refunded you?

So we will see.
FNIRSI 2C53T was released quite recently, maybe hasn't spred between people yet. But maybe it just isn't a good device
 so people don't want it. Who knows.

Thanks

[IC_Toaster]

Hi Ajar171, no the FNIRSI really has the FPGA.
Vendor promotes this on their website.

https://www.fnirsi.com/products/2c53t

✦ Excellent Design: The Oscilloscope adopts FPGA + MCU + ADC hardware architecture, built-in high-voltage protection module, adopts 2.8 inch LCD display, built-in 3000mAh Li-ion battery, standby time up to 6H, Type-C interface supports 5V/1A charging.

AFAIK it has the same HW inside as Fnirsi 2C53P in the package of the old 2c23T
For example FPGA should be GOWIN Semiconductor GW1N-UV2

It has nothing in common with Zoyi. It should be able to do 50Mhz on both channels simultaneously.

Thanks

Storage Depth  1Kpts

I think this in too few memory.

About the Zeeweii:
http://www.zeeweii.com/productinfo/dso3d12.html

It has bigger screen and more storage memory.

[chebo]

Zeeweii looks like some kind of homemade product..

[indman]

Zeeweii looks like some kind of homemade product..

Yes, I agree with you, especially the very jagged font, as if it was made by a not quite sober artist. It certainly discourages the user.
But as an oscilloscope it is much more convenient to use despite its somewhat toy-like appearance. I like that the measurement results are at the bottom of the screen and do not overlap the main waveform. It is a big plus that there is an additional buttons for convenient control of operating modes.