Why the lack of open source scopes? - Page 1
Forum section: electronics / projects

author: openSourceScope
author_rank: Newbie
timestamp: October 02, 2013, 05:31:26 pm
content: Hi All,Recently I've been looking around the web at open source oscilloscopes, and to be honest, I was a little disappointed in what I saw. I had thought that there would be more oscilloscope projects given the importance of an oscilloscope is to anyone working with electronics. The projects that I looked at were quite low end in terms of their specifications such as channel count, bandwidth and sample rate etc. Often the projects appear to be the work of a single person, or perhaps a handful of people. I didn't see any projects where an critical mass had been reached so an active community could come together to really bring a project to fruition.Now, at this point I should probably come clean and confess that I am a professional electronics engineer and that I have been well and truly spoilt by my employers, having access to scopes that cost more than my house. Be that as it may, I still play with electronics as a hobby outside of work and my budgets are clearly several orders of magnitudes lower.... so I am considering making my own oscilloscope, and doing it as an open source project. This would be for my own interest and fun, not to save money. I hope that this wouldn't be just another lone engineer scope project, but rather something bigger. I am wondering why previous projects have not reached critical mass and have come up with a list of ideas. I'm interested to see what you think - do any of these ideas ring true with you, or do you have other suggestions?1. Oscilloscopes aren't sexy enough.Perhaps there just simply aren't enough people in the world interested in making test equipment, and people are far more interested [Raspberry Pi / Beaglebone Black / insert favourite platform here]?2. Current oscilloscope project specifications are too low.Personally the current crop of open source oscilloscopes are just too low end for me to consider them as a useful tool. Osciprime appears to be one of the more mature projects, but with 6MHz sampling rate, and single digit analogue bandwidth, its use is limited to the likes audio or low speed serial work. I wonder whether others feel the same, and are longing for an open source project with specs closer to commercial scopes?3. Components required for higher end scopes are not hobby friendly.Let's face it, most of the cool stuff is BGA packaged, and requires professional assembly, along with high costs. Massive barrier to entry, and the only way to get around it is to make sufficient volume to amortise costs across. That needs a group of people.4. Cost is too high.Perhaps the current scope projects are limited by budget, and those with a little more to spend purchase them selves a commercial unit such as new Rigol, or a second hand Tek? Perhaps Rigol provides everything people want? Perhaps not...... so this makes me wonder whether there is any appetite for open source hardware with specifications exceeding the likes of the Rigol DS1204B or comparable to the Picotech 3506A scopes, but at a price comparable to, or (perferably well) below the DS1074B?Here's the level at which I am aiming the project:* 4 Channels with +/- 15v input range (+/-150v for 10x probe).* 200MHz Analogue Bandwidth* 1GSPS aggregate sampling rate (1ch: 1GSPS / 2ch: 500MSPS / 4ch: 250MSPS)* 512 Megasample Memory (Aggregate across all enabled channels, any combination)* 8 bit vertical resolution.* Network Enabled (1000BASE-T)* Distributed Data Acuqistion Ready* Asymmetrical multi-core processor running Linux + RTOS / Bare Metal code.* No LCD or Buttons (controlled from host PC).Not having an LCD, nor buttons considerably eases the mechanical design and reduces cost, but it certainly won't satisfy many people, so provisions for attaching control buttons shall be made. Similarly some people would not consider a scope that shared their PC, so I am considering adding HDMI monitor output to the scope, which would allow the software to run either on the scope itself as a self contained piece of equipment utilising a standard PC monitor, or as a network enabled device slaved to something else.So that's my idea in a nutshell. Not a cheap project - there are plenty of cheap scope projects already - this is something a little higher end.What do you think?Thanks-Tim

author: Bored@Work
author_rank: Super Contributor
timestamp: October 02, 2013, 05:39:59 pm
content: One of the many decisions one has to make in life is to(a) spend all of your scarce time on developing a non-nonsense, no-toy oscilloscope, or(b) spend your scare time on building something else and using an off-the-shelf oscilloscope for measurement.Apparently, the majority votes for (b).

author: nctnico
author_rank: Super Contributor
timestamp: October 02, 2013, 05:57:52 pm
content: The hardware of a scope is peanuts yet you'd need to sell a lot to make the price attractive to people. I think you end up spending more money on the hardware than buying a readily made oscilloscope. Then again, the largest amount of work is the software. I have an old USB scope project on the shelve; I cancelled it because Rigol and other Chinese manufacturer started to sell cheap scopes.Another well known project is based on the German scopes made by Welec. It might be interesting to reverse engineer an existing scope and write your own firmware with improved features. If the software has a good seperation between the hardware and the user interface you might be able to run the same software on different oscilloscopes in the end.

author: dannyf
author_rank: Super Contributor
timestamp: October 02, 2013, 05:59:24 pm
content: QuoteI don't think sufficient number of people cares about if a scope is open source or not, as long as it does the job.So if you are to go out to build a scope, build a good one that offers decent value.

author: Zbig
author_rank: Frequent Contributor
timestamp: October 02, 2013, 06:02:28 pm
content: I couldn't care less for an open source oscilloscope. This "open source everything" hype just doesn't resonate with me that much. Oscilloscope is a tool and I need it to be solid enough, predictable and finalized (as in "stable", not "perfect") product. The last thing I want from my scope is to have to wonder which nightly build of which of the 18 firmware flavors should I flash into after having to read through 84 pages of forums with some guys arguing with each other over which exact implementation of FFT is the only right one, before being able to probe my goddamn LED blinker.

author: free_electron
author_rank: Super Contributor
timestamp: October 02, 2013, 06:09:44 pm
content: Here's the roadblocks:you'll need fast ADC , multilayer boards if you want any kind of performance, fast memories, know how to make a good PCB. Slap an FPGA in there , have a processor for number crunching , be able to write firmware that can drive a display fast.this is not a 'let's take a raspberry pie and breadboard and a/d up kind of project.You ar elooking at expensive parte requiring know ho how to deal with them from hardware and software perspective.Making a data grabber is easy. making a usefull datagrabber with zero blind time and fast display refresh that can do what a digital scope can do ? that is a huge project ...i'm not trying to come off as negative here but 99.99% of the 'makers' out there are arduino and PI users that can at most drive a motor or blink an led... and it ain't getting better....

author: Marco
author_rank: Super Contributor
timestamp: October 02, 2013, 06:46:11 pm
content: Quote from: openSourceScope on October 02, 2013, 05:31:26 pmEhh, not really ... HMCAD1511 is not BGA, LMH6518 is not BGA, etc etc ... the only thing which is unavoidably BGA is DDR2.PS. a tablet makes more sense as an interface IMO.

author: Neilm
author_rank: Super Contributor
timestamp: October 02, 2013, 07:08:54 pm
content: Quote from: free_electron on October 02, 2013, 06:09:44 pmThere are ways around that.Just take your old monitor to bits and make some circuit to drive the CRT directly

author: senso
author_rank: Frequent Contributor
timestamp: October 02, 2013, 07:09:10 pm
content: A scope with no knobs or buttons, I would avoid that like the plague..You can't really open source the thing, when you start using BlackFins/TI DSP's you need comercial compilers, the IDE's for the big FPGA's used in scopes are not free, at most you can make the boards in Kicad.

author: c4757p
author_rank: Super Contributor
timestamp: October 02, 2013, 07:48:54 pm
content: The software tools don't need to be open. I can write open source programs in Visual Basic all damn day.It might piss a few people off, but so what? It's still open if you can access and use the source.The idea of using KiCad to do PCBs for an oscilloscope is kinda hilarious.

author: senso
author_rank: Frequent Contributor
timestamp: October 02, 2013, 08:04:24 pm
content: I don't mind that someone uses expensive tools to make some open source thingy, but if others want to contribute, they will be stranded, they either buy the tools(or hope that there are "educational" versions to be downloaded).

author: c4757p
author_rank: Super Contributor
timestamp: October 02, 2013, 08:07:54 pm
content: Yeah, but an open source oscilloscope would pretty muchhaveto be made using expensive, proprietary tools.Also, the people with the expertise to actually contribute meaningfully are likely to have access to such tools.

author: free_electron
author_rank: Super Contributor
timestamp: October 02, 2013, 08:13:17 pm
content: Quote from: Neilm on October 02, 2013, 07:08:54 pmDude. we're talking a digital scope here.... not some crap analog shit. besides if you want any kind of speed you need electrostatic deflection so your old tv tube wont work.

author: Marco
author_rank: Super Contributor
timestamp: October 02, 2013, 09:02:20 pm
content: Quote from: c4757p on October 02, 2013, 08:07:54 pmWhy? I think some of the low cost FPGAs can handle the 1 Gb/s rate HMCAD1511 uses, so that can be handled with the free tool chains. Plenty of processors can be programmed with free tools (DSPs are unnecessary). Doing the board with KiCad might be a pain but it's certainly doable. What expensive tools are necessary?

author: c4757p
author_rank: Super Contributor
timestamp: October 02, 2013, 09:03:54 pm
content: If you want to pull off 1 Gsa/s I'd highly recommend, at very least, something which can length-match traces.KiCad has the beginnings of a microwave toolkit which I suspect was a slightly over-ambitious April Fools joke. I think it can do specified-length traces. Good luck doing multiple matched ones.

author: echen1024
author_rank: Super Contributor
timestamp: October 02, 2013, 09:06:40 pm
content: A standalone scope might actually be better...

author: nctnico
author_rank: Super Contributor
timestamp: October 02, 2013, 09:09:56 pm
content: Quote from: c4757p on October 02, 2013, 08:07:54 pmNot at all. I've seen high speed PCB designs made with Geda (scheda + PCB) which is completely open source. Same goes for software: all you need is GCC. Come to think of it. A couple of years ago I worked on a project which included designing a 1GHz ARM based tablet from scratch. The entire project was made using free open source tools.An FPGA design for a scope can be made using the free software provided by the FPGA vendors. Matched impedance / matched length traces are doable in any PCB package. There are plenty of online calculator for the width and distance. Most PCB packages can show you the length of a trace so thats a no brainer as well.

author: c4757p
author_rank: Super Contributor
timestamp: October 02, 2013, 09:13:33 pm
content: Sure, if you can find a team of masochists to do it. Of course, itcanbe done. But I doubt you'll find people who know enough to do a whole oscilloscope who are willing to subject themselves to that...

author: ddavidebor
author_rank: Super Contributor
timestamp: October 02, 2013, 09:18:41 pm
content: Wow that's a boring topic!

author: Marco
author_rank: Super Contributor
timestamp: October 02, 2013, 09:30:19 pm
content: Quote from: c4757p on October 02, 2013, 09:03:54 pmWell it has been done, as I said ... it will be a bit of a pain.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 02, 2013, 10:00:50 pm
content: Ask yourself what you could add to what's already out there at reasonable prices. Maybe a couple of years ago it could have been intensity-graded display, but Rigol have that now...and if you're looking at making it PC based you immediately lose a lot of potential users.If you want to do something novel, maybe a low-cost scope that can stream at USB3 rates might be worth looking at, but other than thgat you are wasting your time - you won't be able to compete with Rigol and/or older used kit.

author: IntegratedValve
author_rank: Regular Contributor
timestamp: October 02, 2013, 10:07:19 pm
content: Excellent idea. Have you checked some of the new TI ADC's? Freescale fast microprocessors? You can do it and you will iff you can:1) Create an embedded computer using a uP and memory from scratch.2) Use ADC/DACs and know how to interface them to the outside world and to the digital world with least possible noise and distortion.3) Take some fresh FPGAs, solder them to a PCB of your own, and program them to do some nasty evil DSP.4) Interface to some high-end LCD display and drive it with your own graphics processing unit made hand made chip? Probably need to implement some graphics API driver to make your life easier.5) Interface to a LCD TFT Color touch screen and create"I would not worry to much about which software to use for PCB traces and such relatively trivial things compared to the above.

author: c4757p
author_rank: Super Contributor
timestamp: October 02, 2013, 10:11:59 pm
content: It's not like there's nobody capable of these things. They happen quite often. If you haven't noticed, China shits them out pretty regularly. Surely there are people in the OSH community who could handle it as well.

author: IntegratedValve
author_rank: Regular Contributor
timestamp: October 02, 2013, 10:18:57 pm
content: Quote from: c4757p on October 02, 2013, 10:11:59 pmThe important is that the OP is capable of these things.

author: marshallh
author_rank: Unknown
timestamp: October 02, 2013, 11:23:57 pm
content: I don't give a **** about it being open source or not. In fact I would actively AVOID something that sold itself that way. It is a tool, not something to be played around with and tinkered on endlessly.I have a feeling OP doesn't know what he doesn't know.

author: nctnico
author_rank: Super Contributor
timestamp: October 02, 2013, 11:44:52 pm
content: Well it would be nice to be able to add extra features in the form of plugins. For example my own USB scope design could show the same signal simultaneously with several different timebase settings. Another feature was a configurable input filter. Sometimes I'm only interested in signals in a certain frequency spectrum. And you could add special measurements (power, crest factor, integration, etc), decoding protocols, do complicated pass/fail on a data transmission, writing data to a file. IOW an oscilloscope could be so much more if you had the ability to write a plugin for pre- or post processing. Ofcourse you could load the data into a PC and process it later but that is just too tedious. My Tektronix logic analyser allows to write plugins and show the results in a protocol decoder window. That opens up a lot of possibilities.

author: free_electron
author_rank: Super Contributor
timestamp: October 03, 2013, 12:36:55 am
content: Quote from: IntegratedValve on October 02, 2013, 10:07:19 pmNo6 : Know how to make an analog front end for the ADC that can accurately handle signals from the millivolt domain to the 100 volt domain with a low noise floor , proper attenuation / amplification and enough safety that it doesn't blow up the first time you put 20 volt or more into the bnc...Making a front end that has substantial bandwidth is not easy ..no7 : know how to do the PCB design and layout for the front end and all the high speed traces and use an appropriate tool that actually can help you getting it right. The digital stuff is just ones and zeros and code. you can design the fpga and cpu code by trial and error. The analog part is the tricky bit to get right. Any mistake in the board design and layout and you can kiss the signal you are trying to capture goodbye. Trial and error in the design of the board will become VERY expensive very quickly if you have no clue what you are doing.I read somewhere on the forum there is a guy that has a team and is thinking about designing a new really hi-end PCB tool ... but i wouldn't wait for that one... it may take a while , they are still trying to figure out the minimum required and it'll probably only run on workstation . I think it'll be a glorified version of 'paint'.But don't let that stop you.

author: IntegratedValve
author_rank: Regular Contributor
timestamp: October 03, 2013, 03:40:36 am
content: QuoteFirst, don't take my comment about your programming experience hard. You may be an analog guru, but "programming" is another realm of mysteries. We still need to differentiate between "programming" and "coding" which many cannot see the difference between the two.Second, and for all, no need to scare someone based on our failures and bad experiences with something. People's abilities are not the same.IMHO, a scope with 1 GHz bandwidth and 5 GSa/s should be pretty doable using available components without resorting to any "proprietary custom chips" which are mainly used to protect from reverse engineering.Just do it. All you need is a soldering iron, solder, a decent multimeter, and a lot of wires. Don't breadboard or PCB it until it's working.Best of luck!

author: krenzo
author_rank: Regular Contributor
timestamp: October 03, 2013, 04:20:54 am
content: Quote from: IntegratedValve on October 03, 2013, 03:40:36 am5 GSa/s?! Really?! Please tell me where I can order this amazing chip at a decent price.

author: casinada
author_rank: Frequent Contributor
timestamp: October 03, 2013, 05:33:08 am
content: 5gs/sec $250 in 1K quantitieshttp://www.ti.com/product/lm97600You can buy the reference board for $5000http://www.ti.com/tool/lm97600rb

author: poorchava
author_rank: Super Contributor
timestamp: October 03, 2013, 07:03:17 am
content: Because this is not something you can slap together out of arduino and some shields. No Teletubbies-level electronics here.1) Components are expensive in low volume. You cannot make a scope with the same BOM as Rigol at the same BOM price. Period.2) Development and experimentation is expensive and there will be A LOT of it. Every spin of 8 layer PCB with controlled impedance + components can easily be $2k-$3k / pcb depending on components. Hand assembly is a big "no-no". BGA/QFN and the life are unavoidable at such speeds. And you obviously don't want to overheat a $100 chip in a toaster oven, do you?3) Know how. You need people with solid industry experience in RF, high speed digital, and precision analog fields. Probably the easiest thing to meet, although such people usually have better things to doThis is basically why scopes are an expensive piece of equipment. They are sold in modest quantities, need lots of money time and knowledge (and the latter two actually also equal 'money')

author: BravoV
author_rank: Super Contributor
timestamp: October 03, 2013, 07:11:01 am
content: Quote from: poorchava on October 03, 2013, 07:03:17 am"Teletubbies-level electronics" ...A sig worthy phrase identified here, applying now.poorchava, you're famous now.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 03, 2013, 07:13:11 am
content: Life was fun as a Tellytubby. Someone must have fed me after midnight...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 03, 2013, 08:12:53 am
content: Quote from: poorchava on October 03, 2013, 07:03:17 amHand placement is entirely feasible, given sufficient skill, a good stencil and a reasonable oven.A while ago I visited a medium-sized assembly house and saw a girl hand-placing big BGAs on a run of 50 boards without even using a magnifier

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 03, 2013, 08:20:28 am
content: Quote from: marshallh on October 02, 2013, 11:23:57 pmAbsolutely - something new/cheaper/better, and by the way it's OS - great.Anything with OS high on the list of features - meh. Just the equivalent of marketing BS.If you want to do something more useful, how about this - reverse engineer and write OS replacement firmware for existing low-cost hardware that is limited by poor firmware and/or expensive option upgrades.Scopes like the newer rigols have no custom parts, so once you spend 5 mins IDing anything with the numbers scraped off, it should be possible to completely discover all the hardware, and write new firmware form scratch to make it work better.

author: mamalala
author_rank: Unknown
timestamp: October 03, 2013, 10:59:39 am
content: Quote from: mikeselectricstuff on October 03, 2013, 08:20:28 amFully agree. There are lots of low- to medium-cost scopes out there which already have a decent quality as far as the hardware is concerned. Rewriting the firmware and FPGA code for such a scope should be doable. Assuming the JTAG for them is accessible, it should be rather easy to figure out how they are interconnected. And in the worst case, just get one and desolder the CPU, FPGA, RAM's etc, and figure it out by probing it.Greetings,Chris

author: GK
author_rank: Super Contributor
timestamp: October 03, 2013, 11:09:32 am
content: Beware the purple teletubbie:"http://news.bbc.co.uk/2/hi/276677.stm

author: Marco
author_rank: Super Contributor
timestamp: October 03, 2013, 01:48:40 pm
content: Quote from: mamalala on October 03, 2013, 10:59:39 amThe way they cripple memory for the lower end scopes would make this very unsatisfying to work on IMO.

author: krenzo
author_rank: Regular Contributor
timestamp: October 03, 2013, 03:37:06 pm
content: Quote from: casinada on October 03, 2013, 05:33:08 amNot bad

author: Unknown
author_rank: Unknown
timestamp: October 03, 2013, 03:58:56 pm
content: Quote from: mikeselectricstuff on October 03, 2013, 08:20:28 amThey kind of did this with the GermanWelec/Wittig W2000A. The company went bankrupt before releasing a usable firmware. There was a project for an open-source bitstream/firmware, but I don't think it ever made it beyond an alpha/development version.

author: Marco
author_rank: Super Contributor
timestamp: October 04, 2013, 08:29:40 pm
content: The Parallela would be an interesting board for an open source scope ... it has everything digital needed, FPGA with fast LVDS (on an external connector), fast memory, fast processor.This eliminates the need for BGA entirely.

author: Whuffo
author_rank: Regular Contributor
timestamp: October 05, 2013, 08:14:03 am
content: The basic problem with this idea is that a scope is a piece of test equipment; you use it to test and verify other electronic circuits. A hand built scope out of threads and zatches would - at best. be of questionable accuracy and reliability. How would you calibrate it?And ultimately, the time you spend building a scope from scratch would be much more profitably spent emptying trash bins at your local McDonalds. Good scopes can be purchased for about a week's worth of McD pay. You won't get a homemade scope up and working in a week.Use the real engineer method: if it's too expensive or unavailable, build your own. Otherwise, buy the manufactured item.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 05, 2013, 08:32:14 am
content: Agreed. If it weren't for the fact that the Chinese have started making usable, cheap scopes in the last few years, maybe there would be more work going on in this area. I even started looking into the possibility of doing a compact 2ch unit myself, in a novel form factor which would make it highly portable and easy to fit onto even the most cluttered bench (as most are when debugging something in my experience!).I soon abandoned the idea, though. It's a huge amount of work, definitely a full time job and with considerable hardware development and tooling costs to recoup. That would have meant selling the hardware commercially even if the firmware were completely open, which in turn would open up a whole can of worms about who was making what from whose efforts - and I can do without the grief.Want a cheap scope? Buy a Rigol, or a second hand Agilent or Tek, and use it to help you design something more interesting.

author: G7PSK
author_rank: Super Contributor
timestamp: October 05, 2013, 09:42:12 am
content: Surely the real answer is you can now buy a reasonable DSO for the same price as a TV.ww.digikey.co.uk/product-detail/en/2530B/BK2530B-ND/2424974?WT.mc_id=PLA_UK_2424974http://www.hughesdirect.co.uk/vision/televisions/pan-txl32xm6b/productWhen the price falls to that level there is no incentive to build it yourself so you are just as likely to find an open source TV as a DSO. they both make the same sort of commercial sense.

author: Marco
author_rank: Super Contributor
timestamp: October 05, 2013, 11:53:17 am
content: Scopes like multimeters are all crippled on the low end ... eventually competition will grind it all down, but that time is not now.PS. of course by the time you make something like this you could have afforded a high end scope as well ... I do think there is a commercial niche for tablet scopes at the moment though, just like there was a niche for USB scopes before.

author: madshaman
author_rank: Frequent Contributor
timestamp: October 05, 2013, 12:48:22 pm
content: Wavelength of 1Ghz is about a foot iirc, seems very doable by hand as trace-length differences won't be large compared to this.

author: openSourceScope
author_rank: Newbie
timestamp: October 09, 2013, 08:32:33 pm
content: Hi Everyone,Thanks for all the replies. Very interesting read. I deliberately didn't reply sooner in the thread as I didn't want to distract, or alter the discussion.Let me clarify some points.Whilst the project would be fully open sourced, it is not something that you would be knocking up on your bench with your trusty soldering iron. The components required for this build will require professional assembly. Most of those people interested in developing an open source scope would be expected to purchase their hardware - the community driven aspect would mainly be an FPGA Firmware and Software project, with the hardware development done by a few people with the correct skills, taking their input from the community ideas & suggestions.The tools used for the schematic and PCB layout will be high end tools rather than open source tools. I don't see much of a problem with this as few people could manufacture their own boards, or stomach the costs of a single board quantity production run. Even if you could; unless your proposed PCB changes are very minor, the work in redesigning the PCB is often not far off that when starting from fresh.Purists may take offence with this, but plenty of very popular hardware is not user manufacturable, and PCB either not released or done in high end tools - Raspberry Pi for example.Calibration, and the suitability of the project as a tool has been questioned. Well, initial calibration would be done in the factory at assembly time, and subsequent calibrations would be done in the same manner as any other piece of equipment. You send it off to a calibration house and they follow the calibration guide. The project is intended as just that... A PROJECT! It isn't intended to replace a trusted commercial scope, but to provide an insight in to the inner workings of such. Perhaps eventually when / if the project matures it could...Some question my ability to produce such hardware. As I said in the OP, I am a professional engineer. I design PCBs and program FPGAs (big ones) as my day job using cutting edge technology including USB 3.0 / DDR3 / DDR4 / Ethernet / HDMI / FPGAs (Multiple Xilinx Virtex 7 2000Ts). The hardest part of the project for me will be the analogue performance of the front end to achieve 200MHz. Where I lack in skill is PC side software design, but there are a lot of people in the world who are very adept it PC software. My shortcoming in that area is one of the reasons I want to do it.My reason for the OP was to gauge whether this is something that I open source and try to build in to something bigger, or whether I simply build two of three for myself. In order to get the cost down to something reasonable such as sub $500USD; it would need to be made in volume batches. In order to do that a Kickstarter project would need to be done so that one hundred+ boards (I just plucked that figure - not done the BOM yet) could be built at the same time. Setting up a Kickstarter project would be a lot of extra work, and it would alter the design significantly compared to keeping it to myself. Hence my OP.The output of a Kickstarter project would be a complete, cased, tested and calibrated, network data acquisition device as per specs in OP (supply your own probes though most likely). The software and FPGA code would come as part of the community project development.At the moment I don't think that there is enough enthusiasm to warrant a Kickstarter project.Thanks-Tim

author: madshaman
author_rank: Frequent Contributor
timestamp: October 09, 2013, 11:40:04 pm
content: Quote from: krenzo on October 03, 2013, 03:37:06 pm+1$250 for 5gs ? Prices going down.

author: fanta
author_rank: Newbie
timestamp: October 10, 2013, 03:12:36 am
content: Perhaps I'm being naive, but I don't think building a reasonable scope frontend is that difficult. Take the low-end of the Tek 7000 series for example, they had bandwidths of around 100-200MHz and were entirely built from through-hole components and double-sided/4-layer boards. Designing one, however, is probably going to be a bit more difficult, especially if OP hasn't done it before. A good start might be to get a vertical amplifier from an old mainframe-type scope (the 7000 series again comes to mind, although I'm sure there are cheaper alternatives) and get your digital back-end working well with that before trying to design your own frontend.You won't get the ultra-low noise floor you'd expect from a modern commercial scope without serious black magic, but you should be able to get something that's Good Enough™.As for why there are no open-source scopes, there are plenty. They're just extremely limited in sample rate and storage capacity (for digital), or require parts that aren't easy to get anymore (for analog). My guess as to the reason why there aren't many good open-source scopes is simple: For a very long time, high-speed ADCs and micros/FPGAs were expensive, hard to get, hard to use, and often covered by NDAs. It's changing now, but unlike, say, software defined radio, most of the people who want one either have one or can easily get one, so there's less desire to build one from scratch.

author: SArepairman
author_rank: Frequent Contributor
timestamp: October 10, 2013, 09:42:45 am
content: Can the code be stolen?

author: GeoffS
author_rank: Unknown
timestamp: October 10, 2013, 09:47:43 am
content: Quote from: SArepairman on October 10, 2013, 09:42:45 amIt's intended to be open source.

author: Seg
author_rank: Regular Contributor
timestamp: October 10, 2013, 09:57:43 am
content: Hardware guys don't understand Open Source. But then again, most programmers don't either.

author: SArepairman
author_rank: Frequent Contributor
timestamp: October 10, 2013, 10:45:25 am
content: i mean why cant we steal the code from rigol or agilenttools for the people!oscilloscopes for everyone!

author: dannyf
author_rank: Super Contributor
timestamp: October 10, 2013, 11:09:35 am
content: QuoteWhy stop there? Why cannot we steal money from you? Why cannot we steal car from you? Why cannot we steal house from you? ...Really, people? Is there really no hope for humanity?

author: poorchava
author_rank: Super Contributor
timestamp: October 10, 2013, 11:40:56 am
content: Quote from: fanta on October 10, 2013, 03:12:36 amThat's another major issue you are touching there: patent issues. The scope would have to be designed in such a way, as to not infringe on any patents held by Agilent, Tek, Hameg, Toshiba, Philips, Hitachi, Rigol, Atten, Siglent, LeCrap, Rhode&Schwarz etc.I think that actually the analog part is the hardest. Digital hardware is pretty simple. Stuff like FPGA/DDR3/ADC schematic and layout can be copied from reference designs and application notes almost 1:1. The most critical part is the code inside FPGA or processor, which doesn't cost anything if you do something wrong - you just upload new version and test.With analog design things are much harder, you can easily expect to have at least 3-4 revisions of the analog frontend before it works even remotely ok, and every revision costs a lot of money.As for stealing code... First you have to get to that code and then defend yourself from omnidirectional legal attack. And that's assuming you live in a place with even half-sane patent law (in other words: not USA).

author: Marco
author_rank: Super Contributor
timestamp: October 10, 2013, 12:10:24 pm
content: Quote from: mojo-chan on October 10, 2013, 09:28:10 amIt's open source ... in the beginning it's good enough if it can do all the straightforward trigger modes at 100 Hz update rate. If it takes off someone will come along to improve it eventually (assuming the hardware picked has sufficient headroom).I actually think you could do the front end with double sided PCBs and hot plate soldering ... as was said by Fanta Tek and others were doing 200 Hz scopes on double sided PCBs decades ago and a lot of their design effort went into what we would now use an integrated PGA for. Running through design iterations with double sided PCBs and hotplate soldering isn't going to drive cost to high heaven.The FPGA/CPU need to be on a 4+ layered PCB, but as I said before you can simply buy the Parallela which is ridiculously good value. A huge advantage of the Parallela which I don't see any way to replicate with a processor of similar cost is that it can take the full 1 GB/s data stream. Normally this would require a processor with something like a multilane PCIE interface (or maybe you could hack something with a large number of GPIO and DMA but it would be quite a feat). So you could even just not do any processing inside the FPGA at all for the initial prototype just decode the LVDS and pass the data on to the CPU.Maybe the ADC needs 4 layers too, but in the short run you could just use an ADC evaluation board with 50 Ohm inputs ... and then just copy paste that reference design later, that's what it's for.

author: SArepairman
author_rank: Frequent Contributor
timestamp: October 10, 2013, 03:44:44 pm
content: Quote from: dannyf on October 10, 2013, 11:09:35 ami would not keep tools out of the hands of the peopleWhat the hell will agilent or rigol care if a few hundred people (maybe) decide to build some time consuming oscilloscope.in the end having the technology in the open will probably bring a net benefit to society at the cost of rigol/agilent anyway.

author: LoyalServant
author_rank: Regular Contributor
timestamp: October 10, 2013, 04:07:52 pm
content: Quote from: SArepairman on October 10, 2013, 03:44:44 pmSpeaking as a software developer that has intimate knowledge of open source vs. closed source.I have worked in both.The obvious benefits to open source is that the end users can alter it in a way that suits their needs or to fix bugs.Close source... well we all know that means we are at the mercy of the manufacturer and quite often that meansyou get one release, possibly two then the hardware is EOL and as a result whatever you got... your stuck with.Since Rigol is being used as an example let's go with that....Rigol is software disabling features on their kit that that means open source is right out.This is the way things are heading so obviously for them it will not bring a benefit.If a few hundred people took their software to put on their cloned hardware you can bet their lawyers will be after someone.So no, you can't steal their software and get away with it.. they will not allow that.

author: Marco
author_rank: Super Contributor
timestamp: October 10, 2013, 06:21:54 pm
content: Quote from: mojo-chan on October 10, 2013, 03:29:30 pmOkay maybe I was a bit optimistic, there is a bit of luck involved fining those few talented individuals with more time than money or sense (or too much money and boredom).QuoteBetween Logic Sniffer and Sigrok it seems to be doing alright.QuoteActually I'm relatively sure a lot of people bother, it's just that most people don't want the headache which comes with sharing code so they just use it privately ... the subset of people using explicitly open source tools obviously will have more people among them willing to share.Any way, improving the oscilloscope's FPGA programming wouldn't require expensive hardware ... a signal generator would be enough.

author: homebrew
author_rank: Frequent Contributor
timestamp: October 10, 2013, 07:11:30 pm
content: Hey guys,where is your open source spirit? Those projects are not about developing competitive products. They can't be!Software is another story. Open source software communities can (and did) develop competitive alternatives (like the linux kernel for example) for existing products in the market (Unix-derivates of that time). Why? (1) Because those projects just relay on brain-power. (2) Because it is very cheap to alter the existing product for an individual contributor.Hardware on the other hand, might be very expensive to alter (think of throwing away a 6-layer board of the oscilloscope example), smd parts can't be reused easily etc...To my opinion, OS hardware projects exist for two reasons: (1) Entering the market with a new and innovative product where the business-case relies on the openness (like Raspberry-PI at the time). (2) Because we can! Because we want to learn and understand! OS hardware artifacts are a perfect way of sharing design knowledge when documented properly. Others thereby can understand why certain design decisions are made etc.Many hardware projects are like that. Take for example all the hobbyists CNC-machines. If those projects are of real value, they tend to be expensive. In fact so expensive that it really makes no sense from an economical perspective. Those hobbyists could send of their milling parts to fabs till the end of their lives for the price of their machines ... And there is generally no argument made that they can not reach professional CNC standards by any means... it's simply not about that.So in my opinion there will never be competitive OS scopes (neither in price nor in performance). Get realistic, let's build a well engineered 100MS/s 20MHz bandwidth scope, 32M samples memory with a standalone display. That would be useful, affordable and most important understandable. And a lot of fun of course!The people participating could practice all flavours of designing electronic products:Digital design, analog design, embedded programming, fpga-design, power supply design, user interface design, case design, etc, etc … lots of opportunities!Take 10-20 interested people, one year of their spare time and a budget of 300$ per prototype …Would be a great endeavour. Wanna pull that off anyone? I'd definitely be interested …Cheers,Peter

author: openSourceScope
author_rank: Newbie
timestamp: October 10, 2013, 08:10:09 pm
content: Thanks for the positivity Peter! :-)

author: madshaman
author_rank: Frequent Contributor
timestamp: October 10, 2013, 08:17:19 pm
content: I'd also be interested in such a project, even of only to verify others' designs, testing etc. but could only dedicate so much time.

author: branadic
author_rank: Super Contributor
timestamp: October 10, 2013, 09:05:31 pm
content: Good luck to find enough active fellowers. I've tried to assure people for a similar project multiple times, but without success. But instead of an 8bit design I was more interested in a 10bit design (something between Rigol and LeCroy) with up to GSps sampling rate and analog bandwidth of up to 500MHz. There are several adcs available for such a task.For to analog input stage you can find an open source solution here, the pickaback board we designed for the Welec scope to replace the original one:http://sourceforge.net/apps/trac/welecw2000a/wiki/HardwareImprovementFurthermore you find an open souce FPGA design inkl. a NIOSII softcore here:http://sourceforge.net/apps/trac/welecw2000a/wiki/niosII

author: Marco
author_rank: Super Contributor
timestamp: October 10, 2013, 09:22:17 pm
content: Quote from: homebrew on October 10, 2013, 07:11:30 pm100 MS/s is the wrong point for a lowball design, 80 MS/s is a sweetspot ...QuoteThat's not really how amateur open source projects tend to work, it's usually one person creating a usable product before a community adds value.BTW, one guy alreadyhalf-madethe hardware for something with these specs ... although he seems to have given up after getting a PCB made.

author: homebrew
author_rank: Frequent Contributor
timestamp: October 11, 2013, 05:27:42 am
content: Quote from: Marco on October 10, 2013, 09:22:17 pmCould you give a pointer of why that is? Definitely no availability issue of the ADCs... Just curiosity!Quote from: Marco on October 10, 2013, 09:22:17 pmExactly! And in my opinion that's why most of the scope projects are half done, or half of the quality reachable. Doing all the design flavours is just to much for one person ...

author: hlavac
author_rank: Frequent Contributor
timestamp: October 11, 2013, 05:41:58 am
content: Real, Open source scope would be a great thing. As we can see from the ridiculous software crippling escapades some scope vendors are pulling, scope hardware is really quite cheap.It would make great sense to have the open source firmware you can duplicate freely, this is where open source helps mankind as a whole!You would need a worthy hardware platform, but thats something a Kickstarter would solve...As for the PC scope concept, yes it makes perfect sense, dont be put off by the knob loving ludite crowdAll we need is enough processing power on the hardware to do the actual processing of the samples, leave the display and controls to the PC...

author: Marco
author_rank: Super Contributor
timestamp: October 11, 2013, 06:43:00 am
content: Quote from: homebrew on October 11, 2013, 05:27:42 amSimply price/performance, sure it's only a 3$ drop in price (which is 33% drop in price for 20% drop in performance) ... but if you are going to lowball any way do it proper.Though I still think the HMCAD1511 is the better IC to do a project around ... slightly higher end (1 GS/s single channel, 250 MS/s quad channel) but still affordable at 64$.

author: Rasz
author_rank: Super Contributor
timestamp: October 11, 2013, 06:52:01 am
content: Chris Gammell our saviour and prophet spoke >year ago on TheAmpHour about a need for a standardized protocol that would let all lab equipment speak/display/use Tablet as a standard UI.Tablets horsepower quadrupled since then. Today it is possible to do all of oscilloscope computing inside a tablet. 4x Arm A9 = >20Gflops, new tablets with OpenCL will hit 60Gflops soon (Mali-T604) or even >250Gflops (top tier mali).Randomly googled Lecroy paper shows some old 18GHz acquisition system doing DSP on Intel P4 (10Gflops) and reaching 2 Mpoint/s.When you get right down to business Digital oscilloscope is just a software defined radio. All you need is an analog part (attenuators/filters/amps), digitizer, and finally some computing bloc + display. Currently computing is done in FPGAs and is secret sauce. If we decouple computing away from the magic closed box on the desk and move it upstream we would for example end stupid licenses for SPI/can/lvds/whatever decoding scam.

author: Marco
author_rank: Super Contributor
timestamp: October 11, 2013, 07:13:26 am
content: FLOPs don't help if you don't have the bandwidth ... for something like variable intensity displays with very high update rates (Digital phosphor as Tek calls it) you need to be able to process at wire speed.

author: Unknown
author_rank: Unknown
timestamp: October 11, 2013, 07:16:11 am
content: Quote from: hlavac on October 11, 2013, 05:41:58 amTo the likes of Rigol and Atten. Not to the hobbyist in one-offs (or hundred-offs). Why not just write an open-source bitstream and firmware for the Rigol DS2000, or the Hantek scope that already runs Linux? Forum user tinhead may have already done some of the reverse engineering for the latter.Quote from: hlavac on October 11, 2013, 05:41:58 amThe usability of a PC-based GUI just sucks compared to a scope with dedicated buttons and knobs. Ask anyone who's used both. I think I've met one person who after using both a stand-alone scope and PC-based scope preferred a PC-based scope. And that was mostly because bench space was at a premium and he found the worse UI and analog performance to be acceptable for his purpose. PC-based is easier for a DIY design if you're building a scope from scratch. But it will again make the product less competitive with the 'real' commercial scopes.Quote from: hlavac on October 11, 2013, 05:41:58 amI would be more worried about how to get the data in the PC at a decent rate, if you don't want to be one of those PC-based scopes with way too slow update rates. USB 2.0 is ubiquitous, but slow. PCIe is fast enough, ubiquitous in desktop PCs, but not that simple to interface. USB 3.0 might be fast enough, but is not that ubiquitous and most USB 3.0 interface ICs are not available in small quantities.Quote from: Rasz on October 11, 2013, 06:52:01 amExcept that the fastest interface available on many tablets is USB 2.0 high speed, which might be able to transfer 24 MS/s or so on a good day.Quote from: Rasz on October 11, 2013, 06:52:01 amJust like a software defined radio, which only has maybe 20 MHz bandwidth at best. And is not DC coupled. Or has to receive signals from millivolts to tens of volts. Or needs a flat response across its frequency range. And a well defined 1 Mohm input impedance.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 11, 2013, 07:28:46 am
content: Any time I'm using my scope, my PC is usually running a compiler, or serial terminal, or viewing a PDF data sheet.It's simply not available for use as a scope UI.

author: Marco
author_rank: Super Contributor
timestamp: October 11, 2013, 07:39:56 am
content: Quote from: alm on October 11, 2013, 07:16:11 am1 MOhm input scopes are just a nasty bit of history which should have been ditched long ago, the front end belongs on the probe IMO. It's only kept around at this point so they can upsell the sane way to do it.

author: Unknown
author_rank: Unknown
timestamp: October 11, 2013, 08:04:18 am
content: From a practical point of view: probes designed for a 1 Mohm input impedance are available cheaply with a bandwidth of about 100 MHz and suitable for voltages from a few mV to a few hundred volts. The cheapest commercial active probe designed for 50 ohm input impedance will probably cost a few hundred bucks. And it will probably only have a fixed range of about +/- 10 V. Useless for low level audio signals or higher level power supply rails.Putting the full attenuation, controls and compensation network in the probe head, which has to be small by necessity, will be tricky. I'm not aware of any commercial product doing this. Designing custom probes, in addition to a scope, does not help in making the project feasible. And what's the advantage? It allows for a lower input capacitance, but that's not exactly your biggest issue when designing a < 100 MHz scope.I guess you could design an external attenuator / amplifier that connects to the 50 ohm scope input, but why? The less boxes on my bench, the better. The only commercial equivalents that come to mind are the buffer amplifiers that allow high-end scopes that are 50 ohm only to interface with high-impedance probes like the Tek TCA-1MEG, but these are not exactly cheap (read: cost in excess of $1k).

author: Rasz
author_rank: Super Contributor
timestamp: October 11, 2013, 10:41:14 am
content: Quote from: alm on October 11, 2013, 07:16:11 amUSB 3.0 is available in small quantities, FX3 does 250MB/sQuote from: alm on October 11, 2013, 07:16:11 amEvery tablet soc these days has extremely fast camera interface. For example i.MX6 has csi-2 at ~3Gbps and cpi 20bit at 180MHz. That would be enough for 2 channel 20MHz, good start I think.Quote from: alm on October 11, 2013, 07:16:11 amAll of that is front end. Community build a family of frontends, starting with cheap ass 2x20MHz and see what software people can do with it.Quote from: AndyC_772 on October 11, 2013, 07:28:46 amSo you are limited to only 1 computer per household?You would swap magic black box Oscilloscope for a PC dedicated to being Oscilloscope. Its not about being cheaper, its about opening up that black box and letting you do whatever YOU want with data. No more stupid UIs, no more $1000 licenses to decode serial protocols, no more being stuck with one color palette, limited to shallow sample memory, or shitty slow math functions. Did I mention no more 3 frames per second Owon GUI?Every time Chinese come up with new scope (or ham radio or whatever doohickie) its ALWAYS the same story - decent hardware (for the price) married with total shit for software. Even western companies can frack up the simplest things, like FLIR E4 Mike tested recently (4 buttons that do NOTHING and 3 levels deep lagging UI to change one of the most often changed parameters). All of it can go away if we decouple presentation and computation layer from the frontend.

author: Unknown
author_rank: Unknown
timestamp: October 11, 2013, 11:25:52 am
content: Quote from: Rasz on October 11, 2013, 10:41:14 amSure, the SoC has fast interfaces. How do you access this without hacking the tablet? Hacking the tablet is going to be particular to one type of tablets, and cheap tablets tend to come and go, so it's hard to standardize on one type unless you pick an expensive type like a Samsung/Apple product. Are you also proposing to build your own tablet?Quote from: Rasz on October 11, 2013, 10:41:14 amMany SDRs don't even have 20 MHz bandwidth, let alone dual channels. Most SDRs use USB 2.0, which can't sustain 2x20 MHz on a single port. So what components would scopes and SDRs have in common?Quote from: Rasz on October 11, 2013, 10:41:14 amYou already can. Any DSO sold today can interface with a computer over USB and/or LAN. Often with a well-documented SCPI protocol if you buy a decent brand. Few people use this for general purpose use (as opposed to logging or automated setups) because it's a pain compared to the stand-alone scope and software availability is poor. Is either of that going to change when an open-source scope comes along? Look at the Sigrok project: none of their GUI's offer a decent interface for a logic analyzer yet. None of the GUI's for the open-source SUMP/OLS logic analyzer is that great either. And the GUI for a LA is much simpler than for a scope.Quote from: Rasz on October 11, 2013, 10:41:14 amSo how about taking that decent hardware that you're not going to exceed in either performance or price in an open-source design and replace that shitty software?In general it seems that you guys are looking to increase the number of challenges, as if reaching your core target is not hard enough. Summarizing your and Marco's post together it seems that you guys want to build an analog front-end, an active probe, the ADC + digital hardware, build/hack a tablet and write software better than that by Owon/Hantek/Atten/Rigol. Each of which alone could easily take an experienced engineer a few months of work, depending on how high you're aiming. If you want to accomplish something, then you should identify the core problem you're trying to solve and focus on that.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 11, 2013, 12:26:56 pm
content: Quote from: Rasz on October 11, 2013, 10:41:14 amNot progress...!My scope has a LAN port and is on my network. It contains a web server which incorporates a very nicely done, fully graphical representation of the front panel that I can view in a web browser, and use to control the scope as well as viewing waveforms.It's about as nice an implementation of a 'PC scope' as I've seen anywhere - and I NEVER use it, because it's a much worse way to operate the instrument than the conventional front panel controls. In terms of usability, ergonomics, the speed at which I can work and the rate at which the display is updated, the conventional front panel is so much better it's not even funny.I use the network interface to capture and save screens so I can include them in reports or email them to customers, and that's it.I think you've got your market and price points a bit confused. $1000 is what you'd have to pay for serial decoding on the better quality bench scopes, not the Owons of this world. You're getting a very polished, fast, responsive and reliable UI on that level of scope, which you'll struggle to match on a PC. The limitations you describe really only apply to the very bottom tier.

author: dannyf
author_rank: Super Contributor
timestamp: October 11, 2013, 12:29:03 pm
content: QuoteTotally agree.The whole thread sounds like a child's dream to me, rather than a well-thought out engineering endeavor: define your problems, define your target niche, define roles / responsibilities and plan out the general framework of how things / modules will eventually work. and then figure out their feasibility - why do you think you can make those individual things happen and why do you think you can make them work together.Otherwise, it is just a bunch of guys drinking their beers while talking about things they have no clue about.

author: Rasz
author_rank: Super Contributor
timestamp: October 11, 2013, 03:16:30 pm
content: Quote from: alm on October 11, 2013, 11:25:52 amhacking = opening the case, unplugging the camera, plugging own cable.Quote from: alm on October 11, 2013, 11:25:52 amIt needs to be done once per device, not the biggest hurdle. USB 3.0 enabled tablets will be here in a year.Quote from: alm on October 11, 2013, 11:25:52 amdsp, software components are already build and tested in open source SDR applications (some even GPU accelerated).Its pretty obvious I wasnt talking about reusing SDR hardware.Quote from: alm on October 11, 2013, 11:25:52 amYes, they let you download small sample window, or preprocessed data, or like AndyC_772 says crappy web interface with laggy javascript net 2.0 joke of a UI.Quote from: alm on October 11, 2013, 11:25:52 amscope has broader usage scenario than logic analyzer so there is a chance more people would work on it. Look at gnuradio or Gqrx for example, difference between fixed function hi-end ham radio and even cheap SDR + open source software is like night and day. It doesnt have to be like sigrok or GimpQuote from: alm on October 11, 2013, 11:25:52 amYou would still have to pay for 2/3 of the box (fpga/soc/lcd) that you never use in case of using frontend/adc and connecting to a tablet/pc. Reusing whole thing is too difficult (as mentioned before in the thread), reverse engineering custom design would limit brain power to few determined hackers versus people who know dsp and can program pc.Quote from: alm on October 11, 2013, 11:25:52 amBest case scenario would be reusing/copying whole frontend up to ADC, and building only PC interface.Lets face it, writing better software than Owon/Hantek is a given, you cant go worse than thatQuote from: AndyC_772 on October 11, 2013, 12:26:56 pmYes, owons of this world usually dont even offer most of the interesting decoders, or responsive UI for that matterQuote from: AndyC_772 on October 11, 2013, 12:26:56 pmHighend scoper _are_ x86 PCs.

author: senso
author_rank: Frequent Contributor
timestamp: October 11, 2013, 03:44:33 pm
content: Not all cameras are the same, I dont believe that every manufacturer and camera uses the exact same pin-out in the connector..Some tablets might be risky to open(example: iPads, need to lift the glued screen)..Yeah, your scope "app" will be run in a sandbox inside a virtual machine, running interpreted code in the host that then makes the calls to the hardware, it might be a bit laggy..

author: AndyC_772
author_rank: Super Contributor
timestamp: October 11, 2013, 03:51:37 pm
content: Quote from: Rasz on October 11, 2013, 03:16:30 pmI said my scope has "about as nice an implementation of a 'PC scope' as I've seen anywhere"The problem isn't the implementation, it's the use of a PC screen and mouseat all. Putting a lot of work into making it faster and more responsive won't change the fundamental fact that clicking buttons on a screen is nothing like as intuitive, easy or comfortable to use as a real front panel.QuoteThat's theworstthing about them. Whilst I don't doubt that having the resources of a PC available makes good sense for post-capture analysis, compliance testing and the like, that's a completely different type of usage model compared to how most - or at least, many - general purpose bench scopes are used.If that's the market you're aiming at then fair enough, a PC plus an acquisition 'engine' probably isn't a bad fit at all. Something that can set up a well-defined test case, capture data in a controlled and predictable way and then analyse the results is certainly a useful tool and well worth investigating.It's not a replacement for a general purpose scope, though.

author: Marco
author_rank: Super Contributor
timestamp: October 11, 2013, 04:06:30 pm
content: Quote from: alm on October 11, 2013, 11:25:52 amSome do though and it canmake good sense.

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2013, 04:50:04 pm
content: If the GUI is portable you could use a small Linux box (many available) to run the user interface. If the FPGA in the scope does all the heavy lifting the user interface only has to draw the dots. In that case you can do a lot with USB2.0 even at 12Mbit.

author: Rasz
author_rank: Super Contributor
timestamp: October 11, 2013, 05:44:10 pm
content: Quote from: AndyC_772 on October 11, 2013, 03:51:37 pmyes, but it is still crap, right?All it does is remote desktop into scope, with noticeable delay.Quote from: AndyC_772 on October 11, 2013, 03:51:37 pmThats the beauty of open design - its trivial to add stuff. USB optical encoded knobs are not rocket science. How many knobs do you have on a scope now? Dave always complains about them not being clicky, or many functions piled on one knob. With open design you could add as many knobs as you like, and dedicated custom buttons. Just think how many times you wished something had dedicated button/slider/knob, but instead was hidden under 3 layer menu.Quote from: AndyC_772 on October 11, 2013, 03:51:37 pmPC based scope doesnt have to equal touch screen.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 11, 2013, 06:14:58 pm
content: Can I offer a suggestion? See if you can borrow a high quality, general purpose bench oscilloscope from somewhere, and spend a while learning your way around it. It'll take time to get really familiar, but it's well worthwhile doing because only then do the strengths and weaknesses become apparent.Around the beginning of this year, I was fortunate enough to acquire two new scopes: one Agilent 3000X, and one Rigol DS4000 series. Both were unfamiliar to me at first, but since then I've spent enough time with them to get to know them both reasonably well.They have similar capabilities, and both UIs are similar enough to the Tektronix scopes I've grown up with that neither has ever felt oddly unfamiliar or off-putting for that reason.Given the choice, though, unless I strictly needed the Rigol's deep memory, I'd pick the Agilent for a given job every single time. The reason is simple - the controls are beautifully judged in terms of weight, responsiveness and precision, which makes it a pleasure to use. There are precious few things it can do that the Rigol actually can't, but I can set it up and make a measurement in half the time. It's all down to the quality and refinement of the UI, and by that I specifically mean the real, physical knobs and buttons on the unit and the way they interact with the display.If you made me drive the Agilent via its remote UI, it would easily be the other way round.

author: hlavac
author_rank: Frequent Contributor
timestamp: October 11, 2013, 10:37:57 pm
content: Quote from: alm on October 11, 2013, 07:16:11 amYou don't need to transfer all the samples to the PC in real time. Process the samples locally. You can then transfer essentially a processed frame buffer to the PC. Easy enough, every webcam does it!

author: Unknown
author_rank: Unknown
timestamp: October 11, 2013, 10:55:27 pm
content: But then you can't do the DSP in a PC. Which was the premise of this thread. You'd need an FPGA, DSP hardware or a really beefy micro to do that at decent speeds.

author: dannyf
author_rank: Super Contributor
timestamp: October 11, 2013, 11:52:48 pm
content: QuoteWhy?

author: Unknown
author_rank: Unknown
timestamp: October 12, 2013, 12:08:51 am
content: Quote from: hlavac on October 11, 2013, 10:37:57 pm

author: Alphatronique
author_rank: Regular Contributor
timestamp: October 12, 2013, 12:10:42 am
content: if someone was willing to design analog front-end / attenuator and softwarei may handle all the digital and pcb whit assembyi just spend my last 5 year working on kind of high speed scope design for my workthat quite easy whit some trick to avoid controlled impedance and similar stuff for keep cost down , but honestly i sure it not possible to make lower cost that rigol or elsep.s.just think a bit more about that and this was my suggestionuse sparten6 for glue ADC to DDR (1 DDR Chip / Chanel) and handel other small thinglike touch screen interface and Front panel ,etc etcthen route a bus from fpga to raspberry pi CSI/DSI connectorso use raspberry for GUI / LAN / USB (HDMI permit to use nice display and start firmware development right now ..so need some one for analog front end / attenuator and trigger circuitand bunch of software developper