Digilent Analog Discovery or budget oscilloscope.  - Page 1
Forum section: electronics / testgear

author: wonna
author_rank: Contributor
timestamp: April 18, 2015, 08:19:12 pm
content: Hi,Would the Digilent Analog Discovery or a budget oscilloscope be better for a beginner. I know I will probably have to upgrade sooner or later to a better scope but money is an issue at present. I'm thinking the extra functions that the Analog Discovery offers would give it the edge but any opinion would be deeply appreciated.Thank you,Martin.

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 18, 2015, 08:39:33 pm
content: What type of work do you plan on using the scope for? It is likely that the Analog Discovery will handle everything you need as a beginner. If you plan to get into higher frequency stuff, then you may need a nice scope - but I dont expect that to be necessary if you are a beginner. The Analog Discovery has the advantages of being portable, small, and easy to use. It also has some useful features for beginners (VCC out, signal generator, etc).

author: drakke
author_rank: Regular Contributor
timestamp: April 18, 2015, 08:43:42 pm
content: I have heard good things about it but how much value it provides depends on where you are located and if you are a student at a recognized institution - prices are radically different. But the Discovery is a very popular item and I don't think you would have trouble selling yours if you are a US student.Dave has talked about this in one of the videos but I don't remember which one.

author: Noise Floor
author_rank: Regular Contributor
timestamp: April 18, 2015, 09:11:08 pm
content: As usual, it comes down to application. I would suggest that if you are more concerned with developing your electronic theory understanding then get the Discovery. If you have a firm grasp of the basics and are looking to build "real things" and plan to build out a bench, get a scope.

author: miguelvp
author_rank: Super Contributor
timestamp: April 18, 2015, 11:33:27 pm
content: I have one with the bnc adapter, and off the bat you can't calibrate the probes. At full turn it undershoots.It's a nice signal gen and haven't tried the logic analyzer etc, but as a scope it will get you by if you don't mind the limitations.Programming is not too bad but you are stuck to use intel cpus, so it's a good device but it does have its limitations.But just for the function gen part of it, I think it's worth it.

author: Muxr
author_rank: Super Contributor
timestamp: April 18, 2015, 11:44:12 pm
content: For an oscilloscope, it has pretty poor specs especially when you consider $279 price point: 100Msample/sec, 5MHz bandwidth.You can get a real Oscilloscope for the same price, the Siglent SDS1052DL for instance: 500Msample/sec and 50Mhz. I mean it's an order of magnitude more capable scope.The only way I could see Digilent being at all worth it is if you can get the US academy discount for $99.

author: miguelvp
author_rank: Super Contributor
timestamp: April 18, 2015, 11:50:10 pm
content: Btw I got mine to run with a Dell Venue 8 Pro tablet by using a powered USB hub (but know that it won't charge the tablet while powered)Also unless you have skinny fingers I would get a touch pen (or whatever they are called) or a wireless mouse/keyboard.But maybe you can do your own HID and make an enclosure for all of it. Still don't know how I can power the tablet while powering the device and keeping the USB data flowing.Function Gen at 1MHz 1Vpp with 90 degree phase on the second channel and I get a nice circle in X-Y modeSo it's worth it but depends on your needs, as for the BNC adaptor, well it's worth it but as I mentioned I can't get any probe to compensate.I'll update with a picture at both x1 and x10

author: miguelvp
author_rank: Super Contributor
timestamp: April 19, 2015, 12:04:58 am
content: Well, not sure why I couldn't before but with the cheap probes I bought from Digilent I can get them compensated just fine.This is the 1KHz test signal from my Rigol DS2072.So if 5 MHz is good enough for your needs and you are willing to depend on a PC and other limitations then I'll say get it, but the real thing is way better.

author: rdl
author_rank: Super Contributor
timestamp: April 19, 2015, 02:01:18 am
content: Quote from: wonna on April 18, 2015, 08:19:12 pmIt all depends on how much you actually have to pay for the Analog Discovery. It is much more than a basic USB oscilloscope, the software is excellent, and I think if you will use all its capability then it's a good deal even at full price. If you can qualify for the US $99 price, then do not hesitate.Definitely watch Dave's review video before deciding, and don't forget it must be connected to a Windows PC (though I understand a cross-platform version is in the works).

author: mtdoc
author_rank: Super Contributor
timestamp: April 19, 2015, 05:39:18 am
content: FWIW the -3dB bandwidth of the scope is actually more like 20 MHz. You can read about their rational for marketing it as a 5 MHz scope on page 16 of thetechnical reference manualPersonally, I think it is a good value even at the full price (and a steal at the $99 student price). It's not just the scope and AWG but the network analyzer and logic analyzer as well ( plus low amp power supply and volt/ampmeter) None of the instruments by themselves are outstanding but the combination of instuments in a small package is very useable and makes a make a great learning tool.

author: Howardlong
author_rank: Super Contributor
timestamp: April 19, 2015, 06:21:48 am
content: Agreed, the analogue bandwidth is way more than 5MHz in practice, it's well into the tens of MHz especially with the BNC adapter and proper probes. The logic analyser is 100MSPS too so good enough for many MCU applications particularly at the low to mid range. It frequently travels with me, the form factor combined with all of the functionality often make it a reasonable choice when on the road.I've been known to have it out on the tray table on planes hooked up to a dev board, but I generally have it surreptitiously located with the wiring hidden away in a box to avoid suspicion of nefarious activities. Even with a portable scope you'd be hard pressed to explain that away to the flight attendant.

author: mtdoc
author_rank: Super Contributor
timestamp: April 19, 2015, 06:29:42 am
content: Quote from: Howardlong on April 19, 2015, 06:21:48 amHa! I seriously considered bringing it, along with my small MSP 430 dev board robot project along on a recent trip to Hawaii. It's a long flight. I thought about the issue of what the flight attendent would say but the real worry was what my wife would have said!

author: Mark
author_rank: Frequent Contributor
timestamp: April 19, 2015, 06:59:20 am
content: To add to what everyone else has said, don't forget that most scopes are 8 bit while the Analog Discovery is 14 bit, which will make a difference if you use it for making amplitude measurements from the scope function, or as a voltmeter. I will be using mine later to compare two high voltage probes.If you can get it for the student price with the bnc adapter then it is a no brainer, it is a very good learning tool for anyone.I also like Howards idea of using it while traveling, it is such a small device that you can carry it in your bag and use it anywhere with a mini dev board.

author: tggzzz
author_rank: Super Contributor
timestamp: April 19, 2015, 07:48:07 am
content: Quote from: miguelvp on April 19, 2015, 12:04:58 amWhat is the compensation range for each probe?IIRC the AD has a 25pF input capacitance, whereas many scope are <=20pF

author: miguelvp
author_rank: Super Contributor
timestamp: April 19, 2015, 08:01:16 am
content: The AD ones are 10-35pF and I thought that's what I was using, also I have other 100MHz ones that have the same compensation range, but maybe I was using a 300MHz one that go from 6-24pF.That would explain it.

author: wonna
author_rank: Contributor
timestamp: April 19, 2015, 09:57:42 am
content: Thank you all for some excellent opinions ~ it has helped a great deal!I'm in the UK, so the student price is out but I can get it for £140 for academic use. The main use would be as a learning tool for Uni and small audio projects at home. I'm interested in all aspects of audio electronics and digital control of those systems. Audio mixing, effects, midi, sound synthesis, so I imagine the Digilent would be a good starting point for those applications when on a tight budget.

author: Keylectric
author_rank: Contributor
timestamp: April 19, 2015, 12:08:03 pm
content: I was not aware of this device but it looks like a seriously nice device for a low cost.Some stuff written in this thread does not make sense.A low bandwith scope is not a lesser scope than a higher bandwith scope and a USB scope is a scope as much as a "bench scope".This device is not a "beginners device", it has spec's you could only dream about 10-20 years ago unless you were willing to sell both your car and your house and the size would probably be like an old 32" TV-set.I'm not even aware of a dual channel bench scope (or other USB scope) with 14 bit dual differential inputs and a two channel gen.In fact, this device seems just about perfect for the work wonna is intending to use it for.

author: Howardlong
author_rank: Super Contributor
timestamp: April 19, 2015, 12:36:01 pm
content: Keep in mind that although it's a 14 bit ADC, it only has two attenuator settings, so as you adjust the vertical part of it is due to the attenuator and part is due to the resolution of the ADC, so you won't achieve 14 bit resolution across the range.The key to why this has a generally good reception is the software. It is well thought out, responsive and well featured.The logic analyser is a bit meh in that it has a somewhat limited buffer, making anything more than short serial decodes difficult.For audio, absolutely, this would be pretty useful, especially as it has an AWG/function generator. Again this is where the software excels, it is easier to use than most bench instruments for setting up the AWG.

author: tggzzz
author_rank: Super Contributor
timestamp: April 19, 2015, 12:43:48 pm
content: Quote from: Howardlong on April 19, 2015, 12:36:01 pmAnd getting better. The beta versions are available on Linux/Wintel/Apple, and allow the user to control the device through scripts.One thing I don't like, however, is the USB connector. It is small and I'm only getting intermittent contact. My ugly workaround is to tape the USB lead to the device.

author: miguelvp
author_rank: Super Contributor
timestamp: April 19, 2015, 05:35:12 pm
content: Quote from: tggzzz on April 19, 2015, 12:43:48 pmI never unplugged it and use a USB extender to connect it to my PC. I do the same thing for all dev kits that have micro USB.So far no problems at all on the connector.Also sigrok.org has it listed under development.http://sigrok.org/wiki/Digilent_Analog_Discovery

author: Smokey
author_rank: Super Contributor
timestamp: April 20, 2015, 04:47:44 am
content: Budget scope. 100%. And by that I mean a Rigol DS1054Z, not an Owon thing or DSO Nano or things like that. At 400USD for the Rigol, it will last you a really long time if you are just starting. If you HAVE to have a logic analyzer (with more than 4 channels since you can use the scope) then just about any cheap LA is as good as the Analog Discovery.Analog Discovery is a fun little toy but it will drive you nuts as a general purpose tool. If nothing else, the jumper header interface sucks.

author: wonna
author_rank: Contributor
timestamp: April 20, 2015, 08:58:03 am
content: Quote from: Smokey on April 20, 2015, 04:47:44 amMy original thoughts were to get the Rigol DS1054Z but the supply time is at least July in the UK, maybe longer and I dislike buying 'old model' kit, Rigol DS1052E etc. I saw Dave's review of the Digilent and thought it may be an option to get off the mark having a few tools in one package.

author: Keylectric
author_rank: Contributor
timestamp: April 20, 2015, 08:59:54 am
content: Quote from: Howardlong on April 19, 2015, 12:36:01 pmHi!Can you point us to where you found that info or explain how you came to that conclusion?Spec says 500uV to 5V per div.

author: Keylectric
author_rank: Contributor
timestamp: April 20, 2015, 09:09:34 am
content: Quote from: Smokey on April 20, 2015, 04:47:44 amWorking with with audio, 48dB extra dynamic range (theoretical difference between 8 and 14 bit), differential inputs and proper sweeps with bode plots and dual channel gen is very good to have. None of this you get with a bench scope below 20000usd AFAIK.These functions is usually much more important than an increased bandwith from 5MHz to 100MHz or whatever.

author: Howardlong
author_rank: Super Contributor
timestamp: April 20, 2015, 10:10:41 am
content: Quote from: Keylectric on April 20, 2015, 08:59:54 amThat's right, but you won't achieve 14 bits across the entire range. Take a look at page 5 of this documenthttp://www.digilentinc.com/Data/Products/ANALOG-DISCOVERY/Discovery_TRM_RevC_1.pdfwhich shows the input attenuator switch, where there are two settings for each channel achieved with a Set of analogue switches connected to a potential divider chain. So there are only two attenuation levels applied to the ADC input.At high sensitivities, the software/firmware is multiplying the ADC's input to show greater gain, it is not happening in the analogue chain. So the ADC resolution/div at 500uV/div is less than the ADC resolution/div at, say, 50mV/div assuming the same hardware attenuator setting is used. The software will saturate the voltages beyond the visible vertical range.

author: Howardlong
author_rank: Super Contributor
timestamp: April 20, 2015, 12:00:04 pm
content: To add: I just measured the ADC quantization with the high gain switched in, it is 400uV irrespective of V/div setting. (The analogue noise floor however is about 5mV p-p with both differential inputs grounded, and about the same with the BNC adapter and a terminator).It looks like the low gain switches in at 1V/div by viewing the noise floor and adjusting the vertical range. This would make sense, the documentation refers to the high gain being in use up to Vdiff<7V, at 1V/div the maximum viewable on screen is 10V.So at 500mV/div (5V total vertical resolution), with an ADC resolution of 400uV, there are 12,500 possible ADC values (5/400e-6). This is satisfyingly close to and within 14 bit resolution.Here are the screen vertical resolutions I calculated for each V/div setting in the software:Code:ADC QuantizationV/lsbHigh res400.00E-6Low res4.24E-3V/divV/maxStepsHigh/Low5E+050E+011792Low2E+020E+04717Low1E+010E+02358Low500E-35E+012500High200E-32E+05000High100E-31E+02500High50E-3500E-31250High20E-3200E-3500High10E-3100E-3250High5E-350E-3125High2E-320E-350High1E-310E-325High500E-65E-312.5High200E-62E-35High100E-61E-32.5HighNote that this is raw ADC resolution. Where there is oversampling at lower timebase settings, these resolutions will increase accordingly.

author: Smokey
author_rank: Super Contributor
timestamp: April 20, 2015, 06:35:09 pm
content: Quote from: Keylectric on April 20, 2015, 09:09:34 amYou can suck a deep memory data capture from the bench scope and perform all the same functionality with a little bit of hoop jumping at better resolution probably.The "Bode plot" functionality of the Analog discovery is just:1) Apply fixed amplitude sine wave at frequency X, measure amplitude of output voltage.2) Increase input frequency.3) If less than max frequency goto 1, else stop.You can recreate that with a scope and function gen you can script pretty easily with higher resolution and take less time. Dave did a whole video on how to cheat and use a frequency sweep with a single shot scope capture to make a bode plot.

author: Howardlong
author_rank: Super Contributor
timestamp: April 20, 2015, 07:02:35 pm
content: Quote from: Smokey on April 20, 2015, 06:35:09 pmWas that for magnitude and phase or just magnitude?

author: Smokey
author_rank: Super Contributor
timestamp: April 20, 2015, 09:56:20 pm
content: True on the phase. I forgot that part of the procedure.The AD also checks the phase offset from input to output when it measures the amplitude. You can do this on the bench scope by having the input waveform on channel 1 and the output on channel 2 and sucking both traces out of the scope for analysis (or use the built in phase and amplitude measurements) on both phases.

author: nctnico
author_rank: Super Contributor
timestamp: April 20, 2015, 10:02:26 pm
content: Ofcourse there are other ways of getting somewhere using different gear. IMHO the DAD is a very nifty tool judging from Dave's extensive video. If you can buy it for the student discount price then I'd go for it and postpone getting a 'real' oscilloscope. But even after getting a 'real' oscilloscope I'm pretty sure the DAD won't be forgotten. It has a nifty bag of tricks which you don't get that easely from other test equipment.

author: LaurenceW
author_rank: Frequent Contributor
timestamp: April 20, 2015, 10:05:31 pm
content: Wonna, Let's try and answer your ORIGINAL question!Either/orfor a beginner, you ask. I'd say the Analogue Discovery is a useful lot of electronics in one little box, it's at a bargain price and it will suit beginners well. It does things that some more expensive 'scopes cannot, but then the reverse is also true. I own BOTH, and find uses and needs for both, but then I am not a beginner.Sure, it doesn't go from DC to light (no, wait - itdoesgo from DC!), it doesn't go down (well) to very small voltage levels, and it doesn't do fancy triggers or advanced protocol decoding. I have other gear when I need to do those things, and these aren't what most "beginners" actually begin with, anyway. It also doesn't put out the cat (wife's job), or remind me when her birthday is coming up (wife, not cat). But it does have a very serviceable signal generator, and the buit in (low current) power supply is just fine for powering your little two-chip project.Yes, the interface connector is a bit "budget", and I too recommend the BNC break-out board. You won't find this little board in many "professional" electronics workshops, but as a first "lab in a box" I reckon it's neat. In a few years' time, you'll know whether you want to trade up to a decent 'scope, signal gen and power supply.My 2 Volts' worth.

author: wonna
author_rank: Contributor
timestamp: April 21, 2015, 11:11:12 am
content: Quote from: LaurenceW on April 20, 2015, 10:05:31 pmThe consensus of opinion seems to be going towards the Analog Discovery, just to confirm the 'budget' scope I would be looking at is the Rigol DS1054Z. Thank you all for your opinions, it has helped a great deal.

author: Howardlong
author_rank: Super Contributor
timestamp: April 21, 2015, 11:29:54 am
content: Quote from: wonna on April 21, 2015, 11:11:12 amYikes, that's a different kettle of fish. I incorrectly assumed your budget was about £140. As a scope, the DS1054Z is far, far better than the Analog Discovery. If you are only interested in a scope and not waveform generation, get the DS1054Z. No brainer. Or get both :-)To achieve the full 14 bit resolution of the Analog Discovery s going to need some jiggery pokery in acquisition settings or post processing, the noise floor is already about 3 or 4 bits' worth. Remember that the DS1054Z already offers 12 bits in high resolution by oversampling.

author: wonna
author_rank: Contributor
timestamp: April 21, 2015, 11:48:16 am
content: Quote from: Howardlong on April 21, 2015, 11:29:54 amSorry to cause confusion, I should have specified the model in my original post. The price for the DAD was £230 and the Rigol £301 when I originally posted but later found an academic price of £140 for the DAD, so originally there was a £70 difference... I was just staying within my original budget of about £300 for the scope.Thanks again for your replies.

author: wonna
author_rank: Contributor
timestamp: April 21, 2015, 02:16:03 pm
content: Quote from: wilfred on April 21, 2015, 01:01:53 pmThat's one of the main reason's I initially stated a budget oscilloscope but it is nice to get an opinion about the Rigol vs the DAD too. I do understand the comparison is really about the advantage of an 'all in one' unit vs a relatively budget scope.

author: R_G_B_
author_rank: Frequent Contributor
timestamp: April 22, 2015, 07:21:56 am
content: A good feature of the analogue discovery is the ability to export waveform and network analyzer data into LT spice and Microsoft office and other such programs. Being able to characterise a transfer function of a unknown process is also another good reason to own one.

author: R_G_B_
author_rank: Frequent Contributor
timestamp: April 22, 2015, 08:19:55 am
content: And you can also do thishttp://m.instructables.com/id/WaveForms-Analog-Discovery-on-Zybo/

author: pascal_sweden
author_rank: Super Contributor
timestamp: April 22, 2015, 09:21:19 am
content: Quote from: R_G_B_ on April 22, 2015, 08:19:55 amWhat are they achieving with this setup? It is not clear to me from the instructable.Is it some kind of automated testing? Or can you explain the experiment? =)

author: tggzzz
author_rank: Super Contributor
timestamp: April 22, 2015, 10:10:12 am
content: Quote from: pascal_sweden on April 22, 2015, 09:21:19 amIt looks like they are running the waveforms software on a development board that consists of ARM processors and an FPGA. The significance is that is nothing like a conventonal WIntel nor Linux PC. That is vaguely similar in concept to the Red Pitaya, although there are very significant differences.Whether that is a benefit for you is up to you to decide.

author: Howardlong
author_rank: Super Contributor
timestamp: April 22, 2015, 10:16:43 am
content: Yes it had me scratching my head as to what the benefit is.If it was wrapped up in a box with knobs etc or a touch screen interface I would get it, otherwise as it stands it's even more junk on the bench with a statement "because you can".

author: tggzzz
author_rank: Super Contributor
timestamp: April 22, 2015, 02:22:18 pm
content: Quote from: Howardlong on April 22, 2015, 10:16:43 amThe Red Pitaya can ensure a tight fast loop between a scope's input and output to some special purpose hardware, with feedback algorithms in either FPGA hardware or software. I doubt that's possible with the Zybo/Waveforms, since the javascript interpreter would be in the loop.I'd have thought the main beneficiary of Waveforms-ARM-Linux would be RPi class machines.Of course "because I can and I want to" is always sufficient justificationBut it would be courteous to have a paragraph describing the benefits of doing it!

author: Smokey
author_rank: Super Contributor
timestamp: April 22, 2015, 05:46:17 pm
content: Since they released the API I've had the feeling the analog discovery would make a good poor man's data acquisition system coupled with a test fixture. Just plug the unit into a pin header on the fixture and away you go with analog and digital source/measurement.

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 22, 2015, 05:49:28 pm
content: Another thing that nobody mentioned about the discovery is how low profile it is. If you are a student, you can bring it to class with you, or put it on your desk. This was a HUGE plus for me in college. I had it in my backpack for when I needed it (debugging a project in the library after the labs closed down, etc). Also, if you are just starting and don't have a dedicated workspace, it can help you keep your area manageable. Big boy tools are great, but they take up a lot of real-estate that nto eveyrone has

author: tggzzz
author_rank: Super Contributor
timestamp: April 22, 2015, 06:42:21 pm
content: Quote from: Smokey on April 22, 2015, 05:46:17 pmDigilent is, I believe, now owned by National Instruments, so I suspect others have had the same idea.

author: Howardlong
author_rank: Super Contributor
timestamp: April 22, 2015, 09:33:33 pm
content: Quote from: tggzzz on April 22, 2015, 06:42:21 pmIndeed, and it remains to be seen how long it will be before NI bean counters and MBAs are let loose start seeing "value by tampering" and "synergies" with them, so far the pencil necks seem to have been kept under control.

author: nuno
author_rank: Frequent Contributor
timestamp: April 22, 2015, 10:51:37 pm
content: Personally I don't like "usb scopes", for the simple fact that you need a computer for them to be useful, and I already have my computer busy with other stuff and a small working desk. For me that is a PITA, but you millage may vary. Usability issues. Just to add another POV.

author: tggzzz
author_rank: Super Contributor
timestamp: April 22, 2015, 10:54:33 pm
content: Quote from: Howardlong on April 22, 2015, 09:33:33 pmThe worst possibility is, arguably, the "everlasting match" syndrome. In other words a small company develops the proverbial everlasting match, and - in order to protect their continuing profits - it is promptly bought and borged by a wooden match company.

author: mtdoc
author_rank: Super Contributor
timestamp: April 23, 2015, 02:51:23 am
content: Quote from: nuno on April 22, 2015, 10:51:37 pmAs mentioned before, the question is not which is the best scope. Clearly, the answer to that question is the Rigol.The question is which instrument is best for a beginner starting out. I would argue that given the price and all the included instruments - the DAD is the best choice - unless one can afford all the instruments from the start.I say start with the DAD then add a real scope, power supply, AWG, etc as you can afford them. The beauty of the DAD is that it will remain useful even after you have those things because of it's portability and other features as previously discussed.

author: Muxr
author_rank: Super Contributor
timestamp: April 23, 2015, 03:26:40 am
content: Quote from: nuno on April 22, 2015, 10:51:37 pmPersonally I wouldn't mind a PC based oscilloscope, it would clear up my desk which already has a computer on it, but they mostly have poor software, price per performance is also poor. The analog front end is inferior and the general responsiveness and speed is not there. That's been my experience with all the ones I tried.Perhaps one day we will have a Rigol of PC based scopes but we're not there yet.

author: tggzzz
author_rank: Super Contributor
timestamp: April 23, 2015, 06:53:37 am
content: Quote from: Muxr on April 23, 2015, 03:26:40 amThat would be more helpful if you stated the ones you have tried.In what way do you regard the AFEs as being inferior in ways not stated in their specification?

author: Muxr
author_rank: Super Contributor
timestamp: April 23, 2015, 01:56:07 pm
content: Quote from: tggzzz on April 23, 2015, 06:53:37 amI own a Bitscope, I've also tried a Hantek.But on the topic of the Digilent Analog Discovery and the analog front end, Dave explains it:https://youtu.be/Aymumu3mYl8?t=262

author: JackP
author_rank: Regular Contributor
timestamp: April 23, 2015, 03:09:13 pm
content: Best USB scope + software combo IME is PicoScope, since the software is the same for £20,000+ to £150 models. Bit pricey compared to the Hanteks et al though. Still don't think any USB scope has a better UI than a bench scope for me.

author: Muxr
author_rank: Super Contributor
timestamp: April 23, 2015, 05:00:18 pm
content: Quote from: JackP on April 23, 2015, 03:09:13 pmPicoscopes look really nice, however they are expensive. 70Mhz, 1GS/s, 4ch is $1,153.00. You can get 2 Rigols and a nice DMM for that price.I do think it's inevitable that they will catch up to standalone scopes in terms of price/performance but they are nowhere near there at the moment.There is also the whole form factor thing. Some people just like using a dedicated piece of equipment with dedicated optimized controls and protection of not frying your computer if you plug your scope into a wrong thing.

author: wonna
author_rank: Contributor
timestamp: April 24, 2015, 06:47:21 pm
content: If the budget oscilloscope option was taken, what would be recommended as a must to have with it? i.e. AWG etc. ~ are there recommended budget device options for the additional kit?

author: tggzzz
author_rank: Super Contributor
timestamp: April 24, 2015, 07:43:42 pm
content: Quote from: wonna on April 24, 2015, 06:47:21 pmNo,generalrecommendations are not sensible unlesseverythingis included! The answers will be very different if you are working on live equipment, or digital logic, or software, or RF, or audio, or low-noise sensors, or DSP, or....It is good engineering practice to define what you want to do/achieve before starting. That way you can ensure you have everything (tools, materials, knowledge) available when needed, and there is no last minute panic hunting for something you haven't got.So, you are going to attach a scope to a Unit Under Test (UUT). What is the UUT's output that you will be measuring? What is the expected behaviour, including fault conditions. How will you kick the UUT into life, so that you can check its output against your expectations?

author: wonna
author_rank: Contributor
timestamp: May 03, 2015, 12:54:41 pm
content: Quote from: tggzzz on April 24, 2015, 07:43:42 pmI understand what you mean and after giving it some thought, for my EE degree I'll probably go for the Digilent AD, as my full requirements are not clearly defined at this point. I would have liked to slowly build a complete 'budget' lab after being out of the EE world for some time but the time I have and the cost would make it difficult. I wasn't keen on the usb scope route but maybe building my lab when I have a clearer idea of my future may be more practical and going down the usb route for the time being would be more appropriate.~Additional thoughts~I was debating about the Rigol DS1054Z coupled with the logic analyser upgrade and maybe a low cost AWG to cover most of the Digilent AD's functionality for general experimentation and small project work, as I am going to require an additional psu anyway... but again this may be overkill until I have a clearer idea of my requirements.

author: Howardlong
author_rank: Super Contributor
timestamp: May 03, 2015, 05:39:54 pm
content: Yesterday I actually used my AD to do something on the lab bench (I usually only use it much when travelling). I built a 7th order LC bandpass filter for a medium wave loop antenna which I'd broadbanded by reducing its Q (2k parallel resistor), to put in front of a fairly broadband amplifier. Because it was a long way from 50 ohms, rather than using a VNA, I used the AD to characterise the filter. Pretty good it is too, although the dynamic range of the AD is a bit low to see how good the stop band is.Regarding other USB scopes, I have had a PicoScope and currently have an old BitScope BS50 and a Velleman WFS210 USB/WiFi. The BS50 I bought for travelling maybe ten years ago. I don't know how to put this any other way, but the software for them all is/was shit. The PicoScope was from about eight or nine years ago, so it might be better nowadays. It sat in a drawer for about three years before I sold it on eBay. The BS50 is no longer fully supported by the software, the AWG for example doesn't seem to work any more on the current software. I did actually use it sometimes when travelling, but since the software broke and I now have an AD, it remains in a drawer. I don't know where to start with the WFS210, calling it a toy just seems too generous a description. The concept is great, a scope you control from your tablet. But yet again the software is just completely shit. I also get grounding error messages all the time. It's very unreliable. I tried to use it twice, maybe I should try again. It remains, as with the others, in a drawer. Maybe I should do a video on the WFS210... that would be fun.

author: wonna
author_rank: Contributor
timestamp: May 03, 2015, 06:31:18 pm
content: Quote from: Howardlong on May 03, 2015, 05:39:54 pmWould you say it would be more sensible to try to build a budget lab around a 'real' oscilloscope then rather than trying to use the AD as an all-in-one tool? I want to make sure I don't go down the wrong path and regret it, as money will be short - I would prefer a solution that would give future flexibility beyond my EE degree without purchasing unnecessary equipment.I understand it is a difficult question without defining the equipment use, personally I'm heavily interested in audio but that may change after/during my studies.

author: tggzzz
author_rank: Super Contributor
timestamp: May 03, 2015, 07:15:58 pm
content: Quote from: wonna on May 03, 2015, 06:31:18 pmGet what is suitable for immediate and foreseeable requirements. Use it to gain experience and then decide about what, if anything, needs to change as new requirements become visible.Is there anyone yo can ask about what is necessary for you studies, and/or what equipment you can borrow?

author: wonna
author_rank: Contributor
timestamp: May 03, 2015, 07:26:52 pm
content: Quote from: tggzzz on May 03, 2015, 07:15:58 pmEither would work for the immediate future. Sorry to keep posting I was just trying to find some reassurance that I was following the best path for a reasonable longevity of the equipment purchased, as finances are difficult and I don't want to waste money while I can still afford either option.So basically it's either the Analog Discovery or the Rigol DS1054Z (maybe with the Digital Analyser add-on) ~ I know other things will be required but this would be the heart of the lab.

author: nuno
author_rank: Frequent Contributor
timestamp: May 03, 2015, 08:36:08 pm
content: The ideal was for you to borrow one or both from friends for a week or so. You'll really never be sure until you start using it. Also, take a look at the user manuals for both.

author: Howardlong
author_rank: Super Contributor
timestamp: May 03, 2015, 08:42:31 pm
content: Keep in mind that for audio stuff, you already have a reasonably good signal generator: your PC's soundcard.

author: wonna
author_rank: Contributor
timestamp: May 03, 2015, 08:57:59 pm
content: Quote from: nuno on May 03, 2015, 08:36:08 pmI don't have any friends but I will take another look at the manuals. The AD is a bit lacking if I remember rightly but I have been studying video reviews of both. Thank you for your suggestion.

author: wonna
author_rank: Contributor
timestamp: May 04, 2015, 01:04:06 pm
content: Quote from: Howardlong on May 03, 2015, 08:42:31 pmThank you for the suggestion, I had considered using it but think I would still need a dedicated signal generator for study of non-audio applications.