New handheld scope+DMM, Fnirsi 2C23T, 2ch, 10MHz/50MSps (Nov 2023)

[tunk]

- claimed 10MHz bandwidth, 50MSps
- 2 channels
- 20mV/div - 10V/div
- 50ns - 10s
- 2.8" screen, 320x240
- size 167x89x35mm
- function generator, 1Hz-2MHz, 0.1-3.3V
- 10000 count multimeter
- around $75 on Aliexpress: https://www.aliexpress.com/item/1005006144235719.html

[tunk]

The manual is now out (English on page 28):
https://img.wqdres.com/res/0/20231109/6d4d7a710da1422bacd13524ecc6bc81.pdf

[axantas]

Just out of curiosity I ordered one. Looking at the specs, it does not try to sell something, it cannot be. Particularly the oscilloscope: It is 10 MHz, not a high value, it can not do properly. Not that I would need another one, but you know, like to have a deeper look at it. Sounds interesting.

[Marc_NL]

I have ordered one today.
Noticed that there is already a new firmware for it (V2.0.1), dunno with what it will be shipped, but here it is anyway -- it's from November 7th, so it's still hot!

https://img.wqdres.com/res/0/20231110/e2c24bc0cb7b4cdeb5333fb8c15eabf1.rar

According to Google Translate, this is the change log:

1. Fix the problem of incorrect calculation of high duty cycle frequency of square wave on oscilloscope
2. Fix the abnormal problem of multimeter range bar
3. Fix some translation display abnormalities

I could not find any reviews of it on AliExpress or the other Chinese webshops, we are the guinea pigs!

[Biosfix666]

Hello from a newbie 

Yesterday i ordered two of them.
As i can see i can do temperature measurement with it.
But, where is the probe to do the mesurement?

Do i need such a probe as it´s in the Zotek Zoyi ZT-702S set?
https://www.amazon.de/XEAST-Oszilloskop-Multimeter-Professional-Auto-Kalibrierungsfunktion/dp/B0C1SLST75/ref=sr_1_1?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1OTKNS26FN6BA&keywords=zoyi%2Bzt702s&qid=1700211269&s=diy&sprefix=zoyi%2Bzt702s%2Cdiy%2C374&sr=1-1&th=1

greets from Germany

[axantas]

It just arrived today. First impression - see photos. I expected the usual brick, but got a compact thing, that fits in my pocket...

First impression, as I do not like RTFM: Astonishing logical menues, guiding you chosing the correct function. Do not read the manual, just use it. I like that.
I am doing a lot of "old tech" projects, usually using tools that exceed my needs a lot. No, not the brick on the right side, this is just used as a size comparsion... Siglent usually does the job.

It just fits the old tech needs. I am just somewhat impressed. It does not claim to do 100MHz - it does 10 - almost, but it can do it.

@Biosfix666: Just tested one of the usual temperature probes - they do their job. You might have to exchange the plugs of the probe to connect it to com and "red"

In my case it was shipped with V2.0 - just upgraded it to 2.01 - dankjewel Marc_NL.

BTW: It comes with a nice P6100 probe - or two - depending on the package.

[Biosfix666]

@axantas

Thank you for testing and the information

greets

[dibu]

does anyone know what the small 1837 marked fpga might be? I'm expecting some chinese one, gowin or the like
also anyone interested in reversing this, making an open source sw for it

I have this on order, i already like it as it is, but having an open source sw for it, it would greatly increase its value.

I don't get it why they bother to laser off chips, it is not like it contains leading edge tech, it has off the shelf parts, and the specs are just ok, nothing impressive.

[dougie]

Got mine few days ago and noticed:

Firmware 2.0.2 is already available on FNIRSI Server.  https://img.wqdres.com/res/0/20231130/27604f59f32c4e22801b61c528475962.rar

Change Log:
1. Boot LOGO analysis is missing
2. LIVE FireWire gear picture position offset
3. The buzzer sound in the on-off position is set to the maximum and is not affected by the system volume adjustment.

However: single trigger event does not work for me.

Especially at low speeds (eg. 50ms/div) it seems when drawing a new line, measurment starts at zero and then jumps to the measured value (5V in my case and trigger set to 4V).
By this a trigger event ALWAYS occurs each time a new line is drawn. Someone able to confirm my experience?

Also my device seems quite inaccurate. Measured a signal in Scope Mode at 4,6V while the same Probe connected to my Tek shows 5,2V 
Thats an Error of 13%

[ph_66]

... Measured a signal in Scope Mode at 4,6V while the same Probe connected to my Tek shows 5,2V 
Thats an Error of 13%

Just my 2 cents: you properly compensated the probe each time you changed, ideally with the same square wave (probably that of the Tek)? I'm asking because I stumbled over this once, too.

Cheers, Peter

[dougie]

... yes I did ... however I don't think compensation will have an influence when measuring DC 

[lizard]

Got mine, echo most of the comments here re. accuracy etc.  Unfortunately I decided to upgrade the firmware to 2.0.2.  Bad move!  Bootloader made it to 99% and screen went blank.  I can get back in to the bootloader (reset pin, then hold menu while powering on), but not much else.  I downloaded the firmware from the FNIRSI site so I presume it's OK.  Contacted FNIRSI support who sent me a direct link, but no joy.  Waiting for a refund from Banggood.  Since I got to keep the non-functioning brick, I'll try diddling with the flash ROM when I get some free time.  Sigh.  At least it was cheap

[dibu]

you could try flash the firmware directly via jtag/swd

the swd pins are routed to a unpopulated header near the reset button, the interface is not locked (at least not on my device), only flash is protected, so you will loose the original firmware together with the loader if you unlock it.
i also tried diddling with the firmware file, it looks like it is complete firmware (without the loader part?) contains also the unknown fpga bitstream.
Maybe you could loose something critical i'm not sure.

you will need to make a minimalist dummy loader to jump to the application reset and adjust the vtor

the main chip is at32 something i can look up the exact part number i don't remember exactly basically a stm32 clone (cortex m4)
i could look up more details if you want to try this, i'm not sure it will work, i haven't tried it, but if it is bricked anyway, what do you have to loose.

i'm still trying to figure out what the fpga and the multimeter chip is.
Also looking for others interested in reversing this.

[lizard]

Thanks.  Was able to pull the documentation for the MCU.  There's also a serial flash (25Q64) adjacent to the MCU - bootloader maybe?  Should be easy to remove and take a look at the contents.

[dibu]

the serial flash is just used to realize the filesystem used to store screen captures, also this is what you see when you connect via usb as usb mass storage. it uses elmchan fatfs. there is nothing interesting/hidden there

[fecus]

I bought this equipment too. I tried upgrade too. It is bricked. Where is the reset pin? Thanks.

[latcakir]

not have xy mode

[KHROMV]

to restore the device to revision 0.4, the firmware version is used  https://drive.google.com/file/d/12FHIXT3cF5Pw5OSnOaCDYWjMch264Il5/view?usp=sharing

[ivgu]

Got mine few days ago and noticed:

Firmware 2.0.2 is already available on FNIRSI Server.  https://img.wqdres.com/res/0/20231130/27604f59f32c4e22801b61c528475962.rar

Change Log:
1. Boot LOGO analysis is missing
2. LIVE FireWire gear picture position offset
3. The buzzer sound in the on-off position is set to the maximum and is not affected by the system volume adjustment.

However: single trigger event does not work for me.

Especially at low speeds (eg. 50ms/div) it seems when drawing a new line, measurment starts at zero and then jumps to the measured value (5V in my case and trigger set to 4V).
By this a trigger event ALWAYS occurs each time a new line is drawn. Someone able to confirm my experience?

Also my device seems quite inaccurate. Measured a signal in Scope Mode at 4,6V while the same Probe connected to my Tek shows 5,2V 
Thats an Error of 13%

Hi,
I am experiencing the same problem with single trigger on the falling edge. It triggers immediately after arming, and starts from 2 squares (4V on 2V per square). I am still at 2.0.1. Did you manage to identify and solve the problem? Thanks a lot!

[dibu]

the fpga is AG1KLPQ48 apparently this is commonly used in similar products, also was mentioned here in other threads

[Kaluluka]

Hi!
I just got one and it has HW:04 but Firmware shows 2.1.0, not 2.0.1....

[pilatomic]

Hello,

So I've been playing around with this device for a few days, and even if it certainly has its flaws, I quite like it as a cheap device I can move around.
The single shot bug was a deal-breaker for me, so I took a look at the firmware in Ghidra in an attempt to fix it.

First, I found a few features that missing from the manual  :
- There is a scope calibration function (DC offset nulling ?) engaged by long pressing "AUTO" in scope mode.
- Long pressing the center button in scope mode moves the traces to their default position.
- Long pressing CH1 and CH2 in multimeter modes enter some calibration mode (didnt try it, I dont want to mess the calibration on mine)

Then I was able to locate the issue with the single mode trigger :
Where I was expecting some sort of indexing issue, I found out they actively zero the sampling buffer before the trigger point !! (see attached picture)
Not sure what they had in mind when they wrote that, but I was able to make the code jump over that "feature" with a single byte change in the firmware.
I also changed the version string from 2.0.2 to P2.0.3 to make it clear what firmware the device is running

You'll find the patched firmware attached to this message, along with 2 screenshots showing the change of behavior from Fnirsi original firmware (2.0.2) to my patched version (P2.0.3)
TRY IT AT YOUR OWN RISK. I am not responsible for any bricked device.
It still doesnt make the single trigger mode perfect, as it samples a relatively low percentage of the time, so it easily misses the trigger point.
I might be able to prevent it to trigger entirely if the trigger point is not in the sampling buffer, but I feel it might look misleading.

To install the new firmware, hold the MENU button before pressing the POWER button (bootloader mode), then plug the device to a PC, and drop the firmware in the newly found USB disk.
If anything goes wrong, you can insert a pin in the hole on the side to reset it, re-enter the bootloader mode, and flash the original firmware back.

Feel free to leave any feedback !

[dibu]

Nice found, i'm interested in making a completely open source firmware for it, it looks like you have more of the SW decoded, more functions, variables, i still have many functions like osci_channel_something, and only very few variables decoded. I would be very interested in your ghidra project if you want to share it.

[tunk]

Nice found, i'm interested in making a completely open source firmware for it, it looks like you have more of the SW decoded, more functions, variables, i still have many functions like osci_channel_something, and only very few variables decoded. I would be very interested in your ghidra project if you want to share it.

EEVblog user pcprogrammer has created alternative firmware for the 1013d and
1014d. If the hardware is similar, then you might use his firmware as a starting point:
https://www.eevblog.com/forum/projects/reverse-engineering-the-fnirsi-1014d/
https://github.com/pecostm32/FNIRSI_1013D_Firmware

[dibu]

i know about this project, and plan to buy the 1013d also at some point, just for the open sw, however i think these are very different from from a hw point of view, this scope-mm is much more limited, tiny cortex-m4 mcu and tiny fpga. But some SW components could be similar, both use ChaN FatFs, graphic lib is somewhat similar, font handling maybe, low level stuff here is from the AT32 HAL, it would be a good starting point overall.

[pilatomic]

Hi Dibu,

Sorry I did not answer sooner, I had a business trip this week, only got back a few hours ago.

Simply fixing and compiling the C code obtained from Ghidra does not make it an open source firmware (as it's still Fnirsi's code, hence subject to their licencing)
Depending on your country, doing so might be illegal, as your firmware would surely reuse some of Fnirsi's code.

What is usually done in that case is a clean room design, where one guy writes the documentation about the existing firmware, and another guy writes a new firmware from that documentation.
That avoid any risk of finding code too similar between the 2 firmwares.

[dibu]

The multimeter IC is SDIC SD7502, the ADCs are 3PEAK 3PA1030

[dibu]

Simply fixing and compiling the C code obtained from Ghidra does not make it an open source firmware (as it's still Fnirsi's code, hence subject to their licencing)
Depending on your country, doing so might be illegal, as your firmware would surely reuse some of Fnirsi's code.

Your post gave me a new boost, i have nearly everything decoded now, apart from some floating point stuff for the siggen and font details, but that is not that important anyways. I newer planned to just re-compile the ghidra output and be done with it, ghidra output is not perfect, even less so the original code, I want nothing to do with the original code, i just need it to understand how the hw works.

Now even the lasered chips are identified, maybe the fpga will be a bit tricky with its weird tooling.

There is nothing special about the firmware, there is no secret sauce, no magic, no nothing, pretty basic stuff, i doubt anyone would complain if i reuse "their" put_pixel func. 

[pilatomic]

I am interested to collaborate with you on writing a new firmware.

The hardware isnt perfect but it has potential, at an incredible price and perfect form factor IMHO.

The FPGA bytestream can be used as is, although the device would benefit from having the triggering in the FPGA rather than done in software in the MCU.
(It is pushed at startup by the MCU to the FPGA).

The DMM IC seems to have its own firmware in another EEPROM. There is a "REL" indicator, but it never lights up, and I don't know if the feature is only missing from the MCU, or also not implemented in the DMM IC FW.

Overall, I agree with you, nothing special in that firmware, except for the unusually high amount of bugs !

[dibu]

Nice 

At first fpga could be threated as fixed function hw.
The DMM definitely has its own firmware, ROM might be OTP, I could not find much info on it, this can be used as is, it seems to be good enough.

It seems that the mcu has the lit rel indicator also the code to show it (@0800f83c), i did not check how one is supposed to activate this feature

[dibu]

user manual says rel works only for capacitance, activated with 'save'

When you first check the firmware, before reading the manual  go straight to the source

[pilatomic]

Damn, must have missed that part in the manual.

Anyway, in the idea of laying the groundwork for a custom firmware, I tried to map all the basic HW info to get started.
Here are my notes :

MCU: AT32F403AVGT7
FPGA: AG1KLPQ48
ADCs: 3PEAK 3PA1030
LCD: 320x240, 16bpp, probably ILI9341 based

MCU pinout :
TMR5:
PA0: (TMR5_CH1) LCD Backlight PWM
PA1: (TMR5_CH2) Buzzer

GPIO_config:
PB2: HIGH to keep device on, LOW to turn off
PC11: Unused ?
PA10: CH1 coupling selection (HIGH for DC)
PE0: CH2 coupling selection (HIGH for DC)
PA4: (DAC1_OUT) CH1_Offset
PA4: (DAC2_OUT) CH2_Offset
PC6: Enable DMM IC when HIGH ?
PD3: Key Power
PB9: Key Auto
PB8: Key CH1
PB6: Key F1 (Move)
PB7: Key F2 (Cursor)
PC15: Key Left
PC13 : Key Ok
PE2: Key CH2
PE3: Key Save
PE1: Key F4 (Prm)
PC14: Key F3 (Trigger)
PA3: Key Down
PE6: Key Up
PE5: Key Right
PE4: Key Menu
PC7: Beep from DMM IC when LOW
PB0: Battery charging when LOW

USART3:
PB10: USART3_TX (DMM)
PB1: USART3_RX (DMM)

USART1:
PA9: USART1_TX debug uart

Attenuators:
PA6: CH1 Attenuator
PD2: CH1 Attenuator
PC12: CH1 Attenuator
PA11: CH1 Attenuator
PA7: CH2 Attenuator
PD12: CH2 Attenuator
PD13: CH2 Attenuator
PB1: CH2 Attenuator

FPGA:
PC10:
PC0: FPGA SPI func select 0
PC1: FPGA SPI func select 1
PC2: Some kind of reset / sync ?
PC9: FPGA CRESET_B
PA15: FPGA SPI_SS
PB3: (SPI3) FPGA SPI_SCK
PB4: (SPI3) FPGA SPI_MISO
PB5: (SPI3) FPGA SPI_MOSI
PA8: CLKOUT
PC3:
PC8: FPGA CDONE

SPI2:
PB12: EEPROM_SS
PB13: EEPROM_SCK
PB14: EEPROM_MISO
PB15: EEPROM_MOSI

LCD:
PD6: LCD_RESET ?
PD4: LCD_NOE
PD5: LCD_NWE
PD7: LCD_NE1
PD0: LCD_D2
PD1: LCD_D3
PE7: LCD_D4
PE8: LCD_D5
PE9: LCD_D6
PE10: LCD_D7
PE11: LCD_D8
PE12: LCD_D9
PE13: LCD_D10
PE14: LCD_D11
PE15: LCD_D12
PD8: LCD_D13
PD9: LCD_D14
PD10: LCD_D15
PD12: (A17) : LCD_C/S

ADC:
PA2: ADC for battery voltage

FPGA SPI FUNC SELECTION :
PC0, PC1
0,0 : Unused
0,1 : Scope buffer
1,0 : Timing config
1,1 : Siggen buffer

PC2 set to "1" before sending FPGA a single 0x00 byte, before any other transfer, then set back to 0
also this on timer event after downloading sampling buffer
  GPIO_write_pin(PTR_GPIOC_0800a3bc,GPIO_PIN_0,1);
  GPIO_write_pin(GPIOC,GPIO_PIN_2,1);
  delay_ms(1);
  GPIO_write_pin(GPIOC,GPIO_PIN_2,0);
  GPIO_write_pin(GPIOC,GPIO_PIN_0,0);

[dibu]

based on the init code, i would say that the display controller is ST7789
spi serial flash is 64Mb in my case, but code supports various sizes, only used for screenshots and startup screen

[dibu]

i think making a dumper, that dumps the complete flash (including loader) over uart/vcp would be useful, so jtag could be unlocked and debug capability restored. So a complete flash backup would be available, the firmware file doesn't contain the loader part.

[goldfoxigor7]

Good afternoon, everyone! does Vrms display incorrectly on firmaware 2.0.3 in oscilloscope mode? the mains voltage is actually 230 volts.

[pilatomic]

Your reply made me curious about how the measurements would be so wrong.
I thought I had seen the worst of the code... and boys was I wrong !
Ready for the laugh ?
Here are parts of FNIRSI's code :

Code: [Select]

vavg = (vmax + vmin) * 0.5;
vrms = vpp * 0.354 // in AC mode
vrms = vavg // in DC mode
This explains your issue ...


 

[Panter72]

Hello guys, greetings to everyone!

I`ve bought this little marvel, and I must say, I LOVE IT!
I use it almost every day now. It is as useful as a camera on mobile phone. You have one with you all the time now. When was the last time you`ve grabbed your camera?
And I am not new in electronics (close to 30 yrs in laboratory chemical / biochemical /environment analysis).

Here is the question: Is there a way for this thing to do DMM data logging, since it can be connected to a PC and also has some internal memory? That would really be useful for me. I know I`m coming as ungrateful now, but having a trend-plot option would do a world for me.

Anyone?

P.S.
For now, I`ve only used the option of screen save as .bmp.

[slavoy]

Your reply made me curious about how the measurements would be so wrong.
I thought I had seen the worst of the code... and boys was I wrong !
Ready for the laugh ?
Here are parts of FNIRSI's code :

Code: [Select]

vavg = (vmax + vmin) * 0.5;
vrms = vpp * 0.354 // in AC mode
vrms = vavg // in DC mode
This explains your issue ...


 

[dibu]

Here is the question: Is there a way for this thing to do DMM data logging, since it can be connected to a PC and also has some internal memory? That would really be useful for me. I know I`m coming as ungrateful now, but having a trend-plot option would do a world for me.

Anyone?

I'm working on making an open firmware for this gadget, this and similar features can be added, I also think this is quite an useful little gadget, not very powerful but good enough, great value for the money. Unfortunately the firmware is sh!t, full of bugs, and not even the most basic optimization is done,compiled with O0.

I made some progress however this is now kind of on hold being summer and holiday season.

[Tunas1337]

Hi dibu, thanks for taking the time to work on that stuff! I am, much like you, interested in reversing the firmware and either making mods, or rewriting it from scratch.

Would you mind sharing your Ghidra file (.gzf format) with me? I'd like to save time and avoid extra work if you've already figured out all the functions.

Thanks in advance!

[StalineShadow]

Hi everyone,

I recently tried to update the firmware on my FNIRSI 2C23T 3-in-1 device. Unfortunately, after completing the update, the device powered off and now won’t turn back on. My PC does not detect the device anymore.

Here’s what I’ve observed:

When I disconnect the battery and plug the device into the PC, a green LED lights up.
When I reconnect the battery and then plug the device into the PC, the LED stays red.
Has anyone experienced a similar issue or have any suggestions on how to resolve it? Any help would be greatly appreciated!

Thanks in advance.

[pilatomic]

Hi dibu, thanks for taking the time to work on that stuff! I am, much like you, interested in reversing the firmware and either making mods, or rewriting it from scratch.

Would you mind sharing your Ghidra file (.gzf format) with me? I'd like to save time and avoid extra work if you've already figured out all the functions.

Thanks in advance!

Hey,

Here you'll find my own Ghidra project and notes :
https://gitlab.com/Pilatomic/fnirsi_2c23t_fw

Hi everyone,

I recently tried to update the firmware on my FNIRSI 2C23T 3-in-1 device. Unfortunately, after completing the update, the device powered off and now won’t turn back on. My PC does not detect the device anymore.

Here’s what I’ve observed:

When I disconnect the battery and plug the device into the PC, a green LED lights up.
When I reconnect the battery and then plug the device into the PC, the LED stays red.
Has anyone experienced a similar issue or have any suggestions on how to resolve it? Any help would be greatly appreciated!

Thanks in advance.

Can you still enter the bootloader mode ?

[StalineShadow]

Hi,
Yes, I have access to the bootloader, but I need the firmware and I cannot find it on the manufacturer's website.

[axantas]

Fnirsi does have an open WhatsApp chat. They are quite helpful there in case of problems. Sometimes, they even provide firmware-files there.

https://www.eevblog.com/forum/testgear/fnirsi-tc3/msg5459951/#msg5459951

[kodlw]

During the upgrade, the new FW was loaded at 99% and the device stopped working. He couldn't even turn or connect to the computer.
Here's how to revive Fnirsi again:
- Connect to your computer
- Press the side button and hold the needle and hold (it is on the right side), pressing the menu and holding, pressing the power and hold. Then let go of the side button.
- Boot loader will show up on the display again
-upload firmware F2C23T-GW-en_v2.0.1.bin (462kb)
And it works again ... ♥ 

New Software 2.1.0 (8/2024) Hw V0.4 is on the page-  https://datoid.cz/MnKD71/f2c23t-gw-en-v2-1-0-bin

[StalineShadow]

Hi, I finally received firmware v2.0.1 from the Fnirsi technical support, and I uploaded it, but unfortunately, there’s still nothing—after the upload, the device remains turned off. I'll wait until tomorrow to receive firmware 2.0.2, hoping that it will work again.

[Tunas1337]

Thank you, pilatomic.

Also, reconstructing the firmware starting from Ghidra/IDA decompilations, and releasing that, doesn't break any laws in most jurisdictions, and certainly not China - it has been done for the Quansheng UV-K5 radio under the Apache license, and no one has knocked on anyone's door or threatened legal action. The entire Chinese electronics industry is based on IP sharing -- there was an article about it that I unfortunately can't find. Having a basis upon which modifications can be made would certainly be extremely useful.

[dibu]

when you have a look a the firmware, you will realize just how bad it is, it doesn't make sense to reuse any part of it, it is good to identify ports, setting and protocols everything else can be built from the ground up, for now we just need the fpga bit-stream (part of the firmware) everything else can be scrapped.

[dibu]

Here you'll find my own Ghidra project and notes :
https://gitlab.com/Pilatomic/fnirsi_2c23t_fw

I checked your project, looks good and in a very large percent correct, it was very interesting comparing it to mine, in many cases we have the exact same function and variable names, to the point that i was wondering if you got hold of my project  , i guess things are just obvious sometimes, from what i can tell you were more focused on things that actually matter, i got more distracted by various not very relevant things like bitmaps/fonts and so on.

[Vad-B]

Guys, I just found that FNIRSI has released a new model, the 2C53T!
Atm no info on their official website, but it's available for order on Ali and the price is around €15 more compared to the 2C23T.
https://aliexpress.com/item/1005007580212627.html

In my opinion, it looks pretty good, just placed an order for it.
I hope the basic device architecture is similar enough to the 2C23T so that dibu and pilatomic might leverage their knowledge to fix the buggy original firmware or create a custom one.

Here’s the comparison table for the things that are different (by me + ChatGPT):

Feature	FNIRSI-2C23T	FNIRSI-2C53T
Sample Rate (Oscilloscope)	50MS/s	250MS/s
Analog Bandwidth	10MHz	50MHz
Storage Depth	32kb	1k points
Vertical Sensitivity	20mV/div-10V/div (X1)	10mV/div-10V/div (X1)
Time Base Range	50ns-10s	10ns-20s
Display Mode	YT/Scroll	YT/Scroll/XY
Waveform Analysis	None	8 basic operations + FFT
Cursor Measurement	None	Available
Multimeter Digits	4 digits (10,000 points)	4.5 digits (20,000 points)
DC Voltage Measurement	9.999V~999.9V	1.9999V~1000V
AC Voltage Measurement	9.999V~750.0V	1.9999V~750.0V
DC Current Measurement	9999uA~9.999A	19.999mA~9.999A
AC Current Measurement	9999uA~9.999A	19.999mA~9.999A
Resistance Measurement	999.9Ω~99.99MΩ	199.99Ω~19.999MΩ
Signal Generator Frequency	1Hz-2MHz	0-50kHz
Signal Types (Generator)	7	13

[tunk]

Guys, I just found that FNIRSI has released a new model, the 2C53T!

Maybe you could start a new thread?

[LVU]

Hi! I've got this device too, and I also get bugged by the single trigger mode issue. I've tried updating the firmware with @pilatomic's fix, but got the same issue as others - update stops at 99%, and then the device doesn't turn on. Updated back to 2.1.0 successfully. Also noticed their sizes differ, so I guess you can't update between different minor FW versions. @pilatomic, would you be able by any chance to release a fix for version 2.1.0 too?

[svolto]

!!! IF YOU BRICKED YOUR 2C32T, READ THIS !!!

I received mine in Chinese with no language options in the firmware and I bricked it while uploading the English firmware.

To unbrick it, just remove the 6 screws on the back, unplug the battery and re-plug it while holding the power button and the Menu button.

This will put you back in the firmware upgrade mode.

I hope it helps.

[goldfoxigor7]

good day! what's new in firmware 2.1.0? can someone share firmware 2.1.0?

[topolarity]

Has anyone else noticed that the signal generator shows bad glitches at its base frequency?

Even the DC output shows glitches to 0 at whatever frequency was configured for the DDS.

[Atlan]

Does anyone have a schematic of the input section? Thank you.

[bffargo]

I picked up the 2C53T and a ZT-703s. From usability, the Zoyi is much better interface, screen quality and readable. Haven't put it through deep tests, just usability.