Author Topic: New bench scope - Fnirsi 1014D, 7", 1GSa/s  (Read 79843 times)

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Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #175 on: November 22, 2022, 03:48:05 pm »
Hello there,

Someone i know just bought one of these Fnirsi 1014S scopes and the specs for the sale were quoted as 100MHz and 1GS/s.
From this thread and the tests shown here, it is only around 30MHz and 200MS/s.

Is there any chance that it was updated to get a higher bandwidth?

He is thinking of asking for a discount from the original price tag but we dont have any way of testing it without buying a new function generator the only one we have right now only goes up to 20MHz so we cant use that.  We also dont really know what the rise time of that generator is so it may do no good to try to test via the rise time of the scope.
If it is as low as tested here, he should be able to get a discount, but if they updated it then he can not get a discount, but we can not test it without buying more test equipment.

Any information on this would be appreciated. Thanks.
 

Online Fungus

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #176 on: November 22, 2022, 03:52:48 pm »
Is there any chance that it was updated to get a higher bandwidth?

No.
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #177 on: November 22, 2022, 04:41:01 pm »
To see if it might be a new version open it up and take a picture of the PCB. Then post that picture here so we can check it for differences. Or search for pictures of the PCB in this thread.

But it is most likely like what Fungus answered, a big fat NO.

Online Fungus

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #178 on: November 22, 2022, 04:43:12 pm »
But it is most likely like what Fungus answered, a big fat NO.

They've ALWAYS been sold as 100MHz and 1GS/s - see the very first post in this tread.
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #179 on: November 22, 2022, 07:00:55 pm »
Yep, just like the 1013D from FNIRSI and the other brands it has been sold under.

It is all a big fat LIE

As with a lot of these cheap scopes that can be found on Aliexpres, Banggood and evilbay :-DD

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #180 on: November 23, 2022, 04:24:42 am »
Yep, just like the 1013D from FNIRSI and the other brands it has been sold under.

It is all a big fat LIE

As with a lot of these cheap scopes that can be found on Aliexpres, Banggood and evilbay :-DD

That's what i thought.  How can they be so deceptive i mean 100MHz vs 30MHz that's a huge difference not even close.
They try to catch people off guard thinking it is a much cheaper scope than the other 100Mhz units, what balls they have.  Maybe they should be reported.
The function generator is strange too, it 'loads' very easy its internal impedance must be high.
Some controls are easy to use but some other controls are hard to use.
He paid $140 USD for it, maybe it is worth that much but it would have been better not to lie about it.

I like that "evilbay" and "Bang-u-good" ha ha.

 

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #181 on: November 23, 2022, 04:26:42 am »
Is there any chance that it was updated to get a higher bandwidth?

No.

I thought so was just hoping for the best.  We tested it the best we could with the equipment we had on hand and it does look like the bandwidth really is 30MHz nowhere near 100MHz.  That's very ballsy of them i think.
I am wondering if he could get a discount now.  They didnt even send a stupid 5v wall wart with it.
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #182 on: November 23, 2022, 06:16:54 am »
They try to catch people off guard thinking it is a much cheaper scope than the other 100Mhz units, what balls they have.  Maybe they should be reported.

Yeah that is what they do and they don't give a crap if it is reported.

The function generator is strange too, it 'loads' very easy its internal impedance must be high.

The schematics can be found here: https://github.com/pecostm32/FNIRSI-1013D-1014D-Hack/tree/main/Schematics/1014D

Some controls are easy to use but some other controls are hard to use.

It starts up relatively quick and responds rather well. Better then the Hantek DSO2D10 I also have. The latter actually has a better front end and can do 1 channel at 1GSa/s.

He paid $140 USD for it, maybe it is worth that much but it would have been better not to lie about it.

Not a bad price. Mine was ~170 euro.

Online Fungus

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #183 on: November 23, 2022, 06:42:24 am »
They try to catch people off guard thinking it is a much cheaper scope than the other 100Mhz units, what balls they have.  Maybe they should be reported.

Yeah that is what they do and they don't give a crap if it is reported.

Who you gonna "report" it to?
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #184 on: November 23, 2022, 06:52:54 am »
Who you gonna "report" it to?

There is such a thing as false advertising. Not sure if you will win when you start a dispute on Aliexpress over this, when bought there of course, and hiring a lawyer to sue might bankrupt you :-DD

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #185 on: November 23, 2022, 11:52:36 am »
They try to catch people off guard thinking it is a much cheaper scope than the other 100Mhz units, what balls they have.  Maybe they should be reported.

Yeah that is what they do and they don't give a crap if it is reported.

The function generator is strange too, it 'loads' very easy its internal impedance must be high.

The schematics can be found here: https://github.com/pecostm32/FNIRSI-1013D-1014D-Hack/tree/main/Schematics/1014D

Some controls are easy to use but some other controls are hard to use.

It starts up relatively quick and responds rather well. Better then the Hantek DSO2D10 I also have. The latter actually has a better front end and can do 1 channel at 1GSa/s.

He paid $140 USD for it, maybe it is worth that much but it would have been better not to lie about it.

Not a bad price. Mine was ~170 euro.

Thanks for the link to the schematic i didnt know they published that.
I'll have to take a look and see what is up with this thing.
 

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #186 on: November 23, 2022, 11:54:00 am »
They try to catch people off guard thinking it is a much cheaper scope than the other 100Mhz units, what balls they have.  Maybe they should be reported.

Yeah that is what they do and they don't give a crap if it is reported.

Who you gonna "report" it to?

I will surely tell their parents on them (ha ha).

I was thinking maybe the sites that they sell them on.  Not sure if the BBB would help or not.
I would not want to see them stop selling though, just being more honest about the specs.
 

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #187 on: November 23, 2022, 11:55:02 am »
Who you gonna "report" it to?

There is such a thing as false advertising. Not sure if you will win when you start a dispute on Aliexpress over this, when bought there of course, and hiring a lawyer to sue might bankrupt you :-DD

He bought his on evilbay.  Not sure if he can get a discount yet or not i think he will try though.

It amazes me how much scopes have come down though in the past 20 years.  Back then a 20MHz would cost about $400 USD and that was for a bottom line cheapie CRT beast.

I once used a 50MHz true phosphor type CRT storage scope way back in the 1970's.  It was a huge thing the size of a small refrigerator.  It was around $3000 USD i think back then.  Almost bought one at Princeton too back in the 1980's but it was so big i didnt want to have that laying around.
« Last Edit: November 23, 2022, 11:59:00 am by MrAl »
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #188 on: November 23, 2022, 12:03:22 pm »
Thanks for the link to the schematic i didnt know they published that.

They didn't. I reversed engineered it. Only thing I did not do is measure the capacitors.

A lot of the software in this thing is also the same as in the 1013D, which I reverse engineered and wrote new firmware for.

The root of the repository the schematics are in, holds a lot of information about both the scopes.

Offline MrAl

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #189 on: November 24, 2022, 06:37:00 am »
Thanks for the link to the schematic i didnt know they published that.

They didn't. I reversed engineered it. Only thing I did not do is measure the capacitors.

A lot of the software in this thing is also the same as in the 1013D, which I reverse engineered and wrote new firmware for.

The root of the repository the schematics are in, holds a lot of information about both the scopes.

Hi,

Oh geeze, that must have been one hell of an undertaking, how did you do that?  Did you have to follow all the traces around the boards?

I just did one for a special kind of relay that had an internal circuit and even that was a pain with one IC chip one transistor and a bunch of resistors, diodes, and caps.  Didnt like doing it either but wanted to know for sure how that thing worked.
Yes i found the small caps unmarked too and probably have to unsolder them to check the values.

I'll check out the other stuff too on that site thanks a bunch for all the work you did.
« Last Edit: November 24, 2022, 06:40:05 am by MrAl »
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #190 on: November 24, 2022, 06:58:17 am »
Oh geeze, that must have been one hell of an undertaking, how did you do that?  Did you have to follow all the traces around the boards?

With the use of a digital multi meter and pictures it is not that big an undertaking. Reverse engineering the software and the FPGA, those are the real undertakings. The software for the 1013D took about a year (not full time of course) to get from the first disassembly / de-compile to newly written functioning firmware. The FPGA took at least 6 months to get from almost zero to a full understanding on what it is made up with.

Wrote about it here: https://www.eevblog.com/forum/fpga/reverse-engineering-anlogic-al3_10-fpga/

Offline chupocro

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #191 on: November 30, 2022, 11:18:26 pm »
I wonder if anyone designed a convenient circuit that could be connected to 1014D's function generator and would be used for adjusting the amplitude.

Maybe an emitter follower not to overload the output followed by non-inverting adjustable amplifier using op-amp(s). Gain should be adjustable from less than 1.0 to some max value (e.g. 12 V).
« Last Edit: November 30, 2022, 11:24:21 pm by chupocro »
chupo_cro
 

Offline chupocro

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #192 on: December 11, 2022, 04:08:38 am »
I tested it with an old circuit I made a few years ago for experimenting with DDS sound synthesis.

ATmega8 @ 8 MHz internal oscillator is generating 15686.27 Hz PWM signal while interrupt routine running at the same frequency is used to adjust duty cycle.

https://youtu.be/n-j5uSacw70
chupo_cro
 

Offline donwulff

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #193 on: December 27, 2022, 07:31:45 am »
Spectacular work with the reverse-engineered firmware! I've been wondering though, given this is the FNIRSI 1014D thread, what are the chances of building open-source firmware for the 1014D as well? it sounds like their hardware is very similar, save for the signal generator? For the price it might be a nice platform to perhaps try some simple signal processing/UI improvements. Maybe I should start with some of the tear-down comparisons of the two models people were referring to?

Also about the true performance. If I understand right both probes have two-channel 100 megasample 8 bit ADC:s? So if the FPGA is indeed driving this at 100 megasamples (And I see the datasheet might have little leeway to increase that higher, maybe?) that would be 2x200 megasamples at 7.5bit?  3nS rise-time spec would mean 6 times oversampling, but I guess the real rise-time is more like 10nS? The 1 Gs/s, while made up, is close to the combined analog bandwidth, so I guess if you knew the waveform and/or it was repeating, you could interpolate up to that? ~200Mhz sine-wave? Then again I suppose they're already using a lot of those tricks.

Basically wondering what the actual specs & capabilities are, derived from the firmware, and if the stock firmware is already using those to the max. Still could benefit from things like stacked & fading traces, trace differences etc.
 

Offline py-bb

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #194 on: December 27, 2022, 07:57:19 am »
What's the 100mhz @ 1Gsample/sec mean? Surely that'd be 500mhz(ish) scope? Or is it combining 5 samples into 1 to use a shitty DAC for better dynamic range?
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #195 on: December 27, 2022, 12:45:49 pm »
Spectacular work with the reverse-engineered firmware! I've been wondering though, given this is the FNIRSI 1014D thread, what are the chances of building open-source firmware for the 1014D as well? it sounds like their hardware is very similar, save for the signal generator? For the price it might be a nice platform to perhaps try some simple signal processing/UI improvements. Maybe I should start with some of the tear-down comparisons of the two models people were referring to?

Yes the hardware is very similar to the 1013D. Only differences are the function generator and the user interface.

The function generator is based on an eight bit R-2R network connected to FPGA output pins. In the FPGA it uses a block of memory to create the signal. Partially looked into the FPGA design while reverse engineering the 1013D FPGA. The sampling system is most likely the same.

The user interface is handled by an ARM MCU which scans the buttons and rotaries and sends the needed information to the F1C100s processor.

The firmware is also very similar, but instead of being controlled with a touch screen it processes the serial data from the secondary ARM MCU. Another difference is the function generator. A lot of the investigation has already been done. There is a Ghidra project with already a lot of the functions identified.

It should not be to big of a deal to make new firmware for it based on what I wrote for the 1013D, but I'm not going to do it  >:D

Also about the true performance. If I understand right both probes have two-channel 100 megasample 8 bit ADC:s? So if the FPGA is indeed driving this at 100 megasamples (And I see the datasheet might have little leeway to increase that higher, maybe?) that would be 2x200 megasamples at 7.5bit?  3nS rise-time spec would mean 6 times oversampling, but I guess the real rise-time is more like 10nS? The 1 Gs/s, while made up, is close to the combined analog bandwidth, so I guess if you knew the waveform and/or it was repeating, you could interpolate up to that? ~200Mhz sine-wave? Then again I suppose they're already using a lot of those tricks.

The performance of the system is based on 200MSa/s for the fastest time per division settings. It then has 3000 samples available of which only ~2500 are used on the display. There is a lot of filtering to make it look smooth. (I removed all of that) For the other time per division settings it only uses one ADC and 1500 samples at max. The sample rate is controlled with the time per division setting. (Which I changed in the new 1013D firmware)

Above ~44MHz the software just calculates a sine wave based on the measured zero crossings and the measured max amplitude. (This has also been stripped)

It might look very nice on the screen, but for realistic measurements it is crap.

Another drawback is the vertical sensitivity, which with only 100mV per division true range with a 1x probe setting it is not very good. The advertised 50mV per division is based on software zoom.

Basically wondering what the actual specs & capabilities are, derived from the firmware, and if the stock firmware is already using those to the max. Still could benefit from things like stacked & fading traces, trace differences etc.

The new firmware could do with improvements and there is also some room in the number of available samples. Now using 3000 samples, but in the FPGA it has room for 4096. But as I wrote above, I'm not going to do any work on it in the foreseeable future.

Take a look at the reverse engineering repository, if not already done so. https://github.com/pecostm32/FNIRSI-1013D-1014D-Hack

Offline donwulff

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #196 on: December 27, 2022, 04:48:47 pm »
Just for the record, I'm aware of the sampling theorem, ie. "a signal has to be sampled at least with twice the frequency of the original signal". "at least" is doing a lot of work there. With 100MHz signal you'd like to have at least 5 samples per cycle to recover any of the waveform. Of course, if you already know the signal is around 200MHz, it would be possible to fit a sine (or square) wave to even fewer measurements. According to the ADC datasheet, it could possibly handle up to 475Mhz (the analog paths likely can't) if you know the waveform you're looking for.

Practical example: Matching signal edges on a bus/to a clock, where you know the signal frequency and are only interested in determining the phase.
 

Offline pcprogrammer

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #197 on: December 27, 2022, 05:33:46 pm »
Even if the used ADC's are genuine it does not matter because the front end is bandwidth limited to ~30MHz. Did not check the order of the filter, but at 200MHz on the input I don't think there will be much signal left to sample. Can't test it because my signal generator only goes up to 100MHz.

There are plenty threads on this forum about sampling and the theory behind it, so not going to fill this one with it.

To do more interesting things with these scope(s) one should write up a better FPGA implementation to at least make use of the available memory in it, to quadruple the memory to 24KB per channel. Still not much compared to for instance the Hantek DSO2D15.

It is a nice platform to play on and develop skills in developing scopes, but that is it, at least for me.

Online Fungus

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #198 on: December 27, 2022, 08:55:51 pm »
Just for the record, I'm aware of the sampling theorem, ie. "a signal has to be sampled at least with twice the frequency of the original signal".

Not quite.

It should be: "a signal has to be sampled at least with twice the bandwidth of the original signal".

Bandwidth != frequency.
 

Offline donwulff

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Re: New bench scope - Fnirsi 1014D, 7", 1GSa/s
« Reply #199 on: December 29, 2022, 08:13:05 am »
Not me derailing the thread to sampling theory, ahem...  :-// Anyway, bandwidth is an important concept for any kind of high-frequency instruments. The sampling theorem was mostly for the benefit of @py-bb asking if 1Gs/s 2 channel scope shouldn't be 500MHz, as well as to pre-empt anyone needing to point out to me that you can't turn 200Ms/s per channel into a full-fledged 200MHz scope, nor should anyone expect that sort of performance. (The sampling theorem doesn't fully hold, however, if the signal isn't fully unknown, which is why I've successfully used true 100MHz scope to align 200MHz bus signals, for example).

But the Nyquist-Shannon sampling theorem is a purely mathematical construct, and as such it assumes a perfectly spherical cow. In other words, the Shannon theorem paraphrased above actually goes "If a function x(t) contains no frequencies higher than B hertz, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart." Of course, the interesting signals in real world aren't pure sine waves (In fact, a perfect square wave is an infinite series of harmonics, to well, infinite frequency. Luckily you don't get a perfect square wave in practice, either) and hence 5 samples per frequency cycle is good minimum to interpolate min, max and zero crossings. And you need to also be able to get your 2 or 5 samples, where every component along the way has a bandwidth limit/attenuation.

I actually acknowledged that with "the analog paths likely can't". In retrospect, it makes sense that there would be an intentional filter around the actual capability of the scope's ADC's, so you don't get aliasing and other unwanted effects from higher frequencies. As a counterpoint though you could alter that filter, and for the signal-aligning use-cases I mentioned, you don't even care about significant attenuation as long as the peaks are discernible. But in the end, I don't expect the hardware can be pushed much further that way. It's just a thought because there ARE use-cases where you don't care about the exact waveform, or where the signal is repetitive so you could fold over the measurements (Unless the sampling rate is a perfect multiple of the signal, you don't even need to shift the sampling points, just align them in software).

Regarding modifying the FPGA, that's a thought, but reviewing some of the earlier thread it seems there's no way to re-program the FPGA via USB or SD-card for example (Could there be a hidden command for it though?) so while exciting, the actual number of people who would be doing that is probably fairly low... At least here in Europe the FNIRSI 1014D is less than half of the Hantek DSO2D15 for example, which places it a price category where you can buy one to toss around, experiment & possibly break, OR use if for hobbyist projects in the 20-30MHz range. But it's certainly cheaper to buy DSO2D15 or even 1013D than trying to replace the existing firmware for personal use. It does look like there's already something bootable for 1014D in the repo though, so who knows.
 


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