Review: Digilent Analog Discovery 2

I recently opened the mailbox to find a little device about the size of White Castle burger. It was an “Analog Discovery 2” from Digilent. It is hard to categorize exactly what it is. On the face of it, it is a USB scope and logic analyzer. But it is also a waveform generator, a DC power supply, a pattern generator, and a network analyzer.

I’ve looked at devices like this before. Some are better than others, but usually all the pieces don’t work well at the same time. That is, you can use the scope or you can use the signal generator. The ones based on microcontrollers often get worse as you add channels even. The Analog Discovery 2 is built around an FPGA which, if done right, should get around many of the problems associated with other small instrumentation devices.

I’d read good things about the Discovery 2, so I was anxious to put it through its paces. I will say it is an impressive piece of gear. There are a few things that I was less happy with, though, and I’ll try to give you a fair read on what I found both good and bad.

Up Front: The Price Tag

analog-discovery-2-thumbLet’s get one thing out of the way up front. This thing isn’t cheap ($279, list price). You have to look at it from the standpoint of value. You are getting a lot of instruments in one and — unlike some others — you can use them (mostly) at the same time. The other thing I was surprised about is that it came with the usual plug with lots of little wires ending in female header sockets. The reason this surprised me is the scope is pretty capable (see below) which means you really want a good set of probes on it. They do sell a $20 board that has BNC connectors on it (but be sure to get it at the same time as the cheapest shipping is almost $20).

I understand the unit is already pricey for this market, so adding another $20 to it (and more if you included cheap probes) might not be very attractive. But for what the scope is capable of, it really ought to include the BNCs. Looking at the Digilent web site, it appears that they are targeting the education market with this device. That means they’ve priced it high and probably offer educational users discounts, especially in quantity.

The Specs

The scope can do 100 megasamples per second and uses a 14-bit A/D. If you have the BNC connectors, you can get 30MHz. The inputs are actually differential (although the device isn’t ground isolated). The waveform generator can go to 12MHz.

Speaking of the capabilities, here’s what Digilent says about it (with a few edits):

  • Two-channel USB digital oscilloscope (1MΩ, ±25V, differential, 14-bit, 100MS/s, 30MHz+ bandwidth – with the Analog Discovery BNC Adapter Board)
  • Two-channel arbitrary function generator (±5V, 14-bit, 100MS/s, 12MHz+ bandwidth – with the Analog Discovery BNC Adapter Board)
  • Stereo audio amplifier to drive external headphones or speakers from waveform generator
  • 16-channel digital logic analyzer (3.3V CMOS and 1.8V or 5V tolerant, 100MS/s)
  • 16-channel pattern generator (3.3V CMOS, 100MS/s)
  • 16-channel virtual digital I/O including buttons, switches, and LEDs
  • Two input/output digital trigger signals for linking multiple instruments (3.3V CMOS)
  • Single channel voltmeter (AC, DC, ±25V)
  • Network analyzer – Bode, Nyquist, Nichols transfer diagrams of a circuit. Range: 1Hz to 10MHz
  • Spectrum Analyzer – power spectrum and spectral measurements (noise floor, SFDR, SNR, THD, etc.)
  • Digital Bus Analyzers (SPI, I²C, UART, Parallel)
  • Two programmable power supplies (0…+5V , 0…-5V). The maximum available output current and power depend on the Analog Discovery 2 powering choice:
    • 250mW max for each supply or 500mW total when powered through USB
    • 700mA max or 2.1W max for each supply when using an external wall power supply

So even they think the BNC board is important. They also left off one of the coolest features — there is a scripting language all over the place for things like custom triggers or orchestration.

I mentioned you could use most of these things at the same time. There are limits, but they are easy to understand. For example, the network analyzer uses the scope channels and the waveform generator. So if you are using the analyzer, you will tie up those resources. That makes sense.

The device is built on an FPGA so it doesn’t suffer from the problem micro-based ones do with respect to sharing timing. All the instruments work fine at the same time. They do, however, share buffer memory. When you connect, you can select from several configurations. Want a 16K buffer for the scope channels? Ok, but it will cost you memory on some of the other peripherals. It makes sense that there is a fixed amount of memory and it is nice that you can make your own choice for how to allocate, within certain parameters.

Basics

Since the device is just a box with some wires coming out of it, the software is everything. Luckily, the software is cross-platform (thank you for that). It is very busy, because there are a lot of features, so you have to explore things. Most items have balloon help (although some don’t, like the UART trigger dialog). The online help is rudimentary and not likely to help you unless you are really new to this stuff.

Still, you can figure most of it out with a little work. For example, here’s the waveform generation screen with a sine wave that has some noise at the extremes:

wave

The main screens have lots of little buttons like the ones on the scope screen:

scope

See the buttons at the top right? The leftmost one shows an overview of the entire buffer. The second one turns on the hot track cursor (the red automatic cursor visible on the waveform). The gear sets some options and the Y button sets the labels.

The gear button is especially annoying. Look down the right-hand side of that screen. There are three more gear buttons! Granted, those are easy because, obviously, those are options for channel 1 and 2, but in some cases, it is hard to remember exactly which gear button is hiding some obscure option you are looking for.

Digital

The digital section works about the same. You can trigger across instruments (so you can trigger the scope when an SPI value comes in the digital ports). There’s fair protocol conversion for things like UARTs and the like. The documentation on these is pretty sparse, though (or I didn’t find it) so expect to experiment. For example, my normal scopes let me invert an RS232 signal before decoding it. I didn’t find an option for that. Maybe it is smart enough to figure it out. Or maybe I could just flip the scope leads. But without trying it, you can’t tell.

In fact, I had a lot of trouble with the protocol decoding. I wrote a really simple Arduino program just to generate a test pattern:

void setup() {
 // put your setup code here, to run once:
 Serial.begin(9600);
}

int ct=0;

void loop() {
  if (ct++==1000)
  {
    ct=0;
    Serial.write("B");
  }
  else if (ct==1)
  {
    Serial.write("C");
  }
  else
  { 
    Serial.write("A");
  }
  delay(1);
}

My idea was to trigger on the letter B and maybe even watch it with the scope. At first, I didn’t have the delay at the end of the loop. I was sending as fast as I could. I could decode the data, but triggering didn’t work. I didn’t realize it at first, because it was in auto mode, so it would eventually trigger itself and I was perplexed that I couldn’t find the “B” in the data stream.

Once I went to normal triggering, it simply didn’t trigger at all. I theorized that it wasn’t able to figure out which bit was a start bit in the middle of a stream like that. In all fairness, my Rigol DS1154Z couldn’t figure it out either. However, a very brief delay (1 or less) allowed the Rigol to grab the data reliably and trigger. I never got it to work with the Discovery.

trig1In all fairness, a new version of the Analog Discovery software appeared right after that and now it works, although it requires a longer delay between characters than the Rigol does. In addition, the manual trigger button at the bottom of the screen doesn’t appear to work — at least, not while waiting for a serial trigger. Turns out, I later figured out that unlike a manual trigger button on a conventional scope, this button only works if you have the trigger set to manual. You can’t override a normal trigger with the button. Seems like the button ought to be disabled if that is the case.

The UART trigger, it turns out, is just a wizard (see right) that sets a complex trigger for you. You can also trigger on a break or an idle condition. Obviously, you can’t (with this dialog) do multiple characters or anything else exotic. You might be able to do it with the actual complex trigger that it defines for you.

Here’s the actual letter B trigger. There is not much help for some of these screens, including this one. Most of it is easy to figure out, but still, it would be nice to have the balloon help, at least.

The Verdict

It may sound like I’m being harsh on the Discovery 2. I guess I am, but I am actually mostly impressed. The hardware seems to be great. The software needs some work, though. If this were a $50 product, it would be a no-brainer. If the software were open, it would get fixed and enhanced very quickly.

However, it isn’t. For the price of the unit — especially adding in the BNC connectors — you could buy a pretty nice 2-channel scope. True, the Discovery is a lot more than that, but it also has its limitations. We’ve seen cheap function generators, power supplies are a dime a dozen, and there are plenty of logic analyzer options. The network analyzer — if you need it — might be the one game changer. The ability to script everything together could be a big deal, too, if you do a lot of automated testing. It isn’t quite like having GPIB keeping a rack full of gear working together, but in some ways, it is similar and maybe even better for most of us.

On the plus side, it is compact and portable. It is everything in one package at one price. If you really bought all the things the Discovery can do, you’d spend more. But you’d also probably get a little more, too. For example, the largest buffer you can field for the scope is 16K per channel. That’s not much these days.

I was intrigued with the network analyzer and I’ll post when I’ve had some time to play with it. That is the one piece of gear you’d be hard pressed to replace at the price.

Is it good? Yes. Is it perfect? No. Should you buy one? That’s going to be a personal decision. It is too pricey for an impulse buy. It is definitely useful but only you know if it is useful enough to part with a few hundred dollars. Maybe a hackerspace or other group could put together a group buy and negotiate a better bulk price–I don’t know, but it never hurts to ask.

I’ve looked at cheap scopes before, and some of them were PC-based too. They aren’t in the same class as the Discovery 2, but they are also a fraction of the price. The closest thing I can think of to the Discovery 2 is LabTool (which I mentioned obliquely in an earlier post). It is cheaper but suffers from using a microprocessor, so it can’t do everything at once, and the more you do, the fewer samples you can take. On the other hand, it comes with BNC connectors.

Further Review

This review shared my thoughts on the Analog Discovery 2 but I didn’t actually demo it. For more on that you can see a video from Digilent that shows you a lot of the features below. There’s also a video from [Nezbrun] that compares it to the older Discovery that this unit replaces.

Editor’s Note: The review unit for this article was given to Hackaday by Digilent without charge.

57 thoughts on “Review: Digilent Analog Discovery 2

    1. Always assume the reviewer got it for free, even if they say they didn’t. People don’t realize that was the real issue behind Gamergate, but I digress.

      Regardless, this doesn’t read like a paid advertisement, and lists pros and cons fairly enough for me.

          1. Guess what? I’m buying you one of these. Just send me an email (last name at most obvious domain) from the email used to post this comment, and we’ll work out the details.

            How’s that for giving back to the community. Pretty magnanimous of me, right?

          2. Well, it is really just silly. I’ve been writing about technology since the late 1970s, way before the Internet. I like to think I have some modicum of a “brand” as the marketing people would call it. Do you really think I would sell out that brand–or that Hackaday would–because I covet a $300 widget? When I wrote for Dr. Dobbs and a few other magazines we used to get review stuff by the crate. No, we don’t send it back, but I have given away a lot of it to schools or students over the years.

            There was a time I made a living writing. Thanks to the Internet and the “how dare you get paid for information” mentality, you can’t do that anymore. Yet folks like me keep doing it anyway.

            It is kind of sad though. If I really loved a product and raved about it, folks like you would accuse me of selling out. Kind of like being a Nigerian prince that really does need someone to help him launder money. Hey… I really like the book the Art of Electronics and I get free copies of books from publishers. I’m probably just a big ole sell out, you think?

      1. Point taken (& agreed re: gamergate).

        I’ve been spoiled by the recent ‘fuck being a marketing shill’ teardowns a la AvE [where every single unit is either mailbag’d or out-of-pocketed from his oil-blood-money ;)] or the absolutely *blatant* full disclosures of Sharhiar of The Signal Path [e.g. “yeah this 120k pre-production scope was sent to me as a demo unit for x days to evaluate due to my historical relationship with Agilent (keysight, whatever, still HP to me) — in exchange, I have access direct access to their engineering team to help work out kinks, etc”]. Probably so much so that my formerly well calibrated cynic-sensor perhaps needs to be sent off to a reference for cal ;)

        That whole unspoken “we give you gear for free, just don’t say anything too negative about it or guess what next Milkwaukee Fuel M4000 5-piece won’t be sent to you” is complete bullshit and I’m glad it’s on it’s way out. The best product placement ads are those that specifically *don’t* read like paid advertisements. ;) [I.e. woodworkers are getting real quality Rockler gear in exchange for promotional time and presumably monetary compensation — though Youtube has been actually surprisingly good about denotating such.

        The best ads really speak for themselves and a billion people will be asking “hey what carbide insert were you using to make such a clean facing cut in 8360 steel?! Christ all mighty, AND no chatter? no nothin’.

        I’ve probably spent a few thousand dollars on hobbyist metal consumables alone based on Fenner’s recommendations (who incidentally is really good about disclosing the entire process-chain of acquisition — “I wanted a CNMG holder, ordered it, but turns out I got the number wrong. They were great about it though and comped my account AND sent out the holder I wanted”.) I’m sure their customer-relation management software has him noted as a VIP, so when the rep took the call they gave him the presidential treatment, but it feels like the opposite of the used-car salesmen sleaze we’re all used to. Anandtech is also superb w/r/t integrity. I’m not ragging on HAD. You all are on the whole really good about not shilling.

        If I haven’t rambled on long enough, I really want to do a ‘full tool review’ a la AvE for every item and just stress test the hell out of everything. Marketing fucks claim your output shaft is transmitting ___ torque at ___ rpm? Welp, I just happen to have a tach and torque transducer. Let’s see if you’re full of shit. Your brushed DC motor has really no inductive spike, welp let’s see what mr Power Analyzer has to say.

        Hey Mike….. if you want to use the ‘hackaday name pull’ with some vendors for sample units, I’d be more than happy to do a completely unbiased (except for my well known love for Fein gear, which will fully be disclosed ;)) tear down ‘this is bullshit, and I can prove it’. I.e., this “tool battle” was such shit it made me so mad, I just ranted and raved here — https://www.youtube.com/watch?v=fY59W1U0lmI&lc=z13aura4mvnss5dvr23pcpqw3oqdynb2c . (Obviously the testing will be conducted with more rigor, a la Anandtech). Go keep the proceeds to keep hackaday &/or setting up a ‘fund’ for HAD members who have taken a marketable product to prototype proving technical viability but don’t have the initial capital to pay 10 grand for a tool&die maker to make those injection molds for the enclosures.

    2. I paid full price for this unit revision 2 after using revision 1. I can say as a paid for device owner with no attachment to digilent that the review is very fair. I personally really like the AD2 and think the pros far out weights any limitations and the value of the tool is well worth the price.

      1. I purchased an AD1 as a student at educational pricing. I came back years later to buy an AD2 with accessories, then a Digital Discovery with accessories, both at full price.

        Wanted my employer to purchase the AD2 for me (I’m an embedded software engineer). They were moving too slow, so I purchased it on my own dime. I don’t regret it.

        AD2 is a great “Swiss Army Knife”. It easily fits on my desk. It lives in my desk drawer when not in use. It travels in my backpack. It was cheap enough to buy on my own dime and avoid red tape. It’s not a replacement for a heavyweight scope or waveform generator or bench power supply in every situation, but it fulfills >> 80% of my instrumentation needs at << 20% the price, and frequently saves me the hassle of dragging projects from my desk to the lab.

  1. I (not associated with Digilent or Analog other than as customer) got an AD2 as well. At that time I had some spare money, so overlooking the price I’m quite happy with it. It isn’t all that well suited as Oscilloscope (although it does a fair job I think), for troubleshooting I prefer my Rigol 1054z (not the least due to more sure-footed triggering and UI elements — ah, all those buttons ;-) or function generator (see http://www.eevblog.com/forum/testgear/show-us-your-square-wave/msg1098443/#msg1098443) even though it goes to a considerably higher frequency and offers arbitrary waveforms unlike the POS function generator I got at Fry’s for 2/3 the price of the AD2.

    The real value (for me) is in the frequency and network analyzer. Sure, one can get much better devices from Agilent on the 2nd hand market for reasonable prices (<$2k), but that's not only quite a different price range, but those devices tend also to be very bulky and heavy (and hence would require a very understanding SO). As a frequency analyzer, the AD2 beats many oscilloscopes (thanks to the 14bit ADC and display on a large screen). I enjoy most however comparing a simulation with the results from the network analyzer (and trying to figure out where the differences stem from).

    Those USB oscilloscope-like devices stand and fall with their software. The one for the AD2 (WaveForm 2015) fortunately gets most things right and while not open, it's at least free (as in beer). I was pleasently surprised when I discoved that the Windows version even runs on an old laptop of mine, sporting Windows XP SP2(!), which allowed me to take some measurements floating (laptop was battery powered).

    1. In all fairness, it is not exactly an “apples-to-apples” to compare this box to a stand-alone scope. Real instruments take up real space. You could throw an Analog Discovery 2 into your bag along with an Arduino and breadboard and carry the whole thing to your local coffee shop with your laptop and do hardware hacking in front of a barista. That would be quite impractical with a real scope, power supply, and logic analyzer.

      I actually have a mixed-signal scope (4 analog, 16 digital), but an older one, from back when scopes were at least 16 inches deep. I want one of these boxes just for the space savings on my desk. If this box can do at least 80% of what I need in a package the size of a deck of cards, I call that a win.

      It is a pity about the price, though. I remember them being offered to students for right around $100, so I know that the BOM is not more than that. If I could get it with the BNC board for $200, I would be VERY tempted. However, at $300 with the BNC board, I can get by with what I already have.

    1. I’m going to assume you have a BitScope 10 since that one was similar in price ($245.) It has a higher bandwidth (100MHz vs 30MHz,) but a much smaller sample rate at 40MS/s where the analog discovery has 100MS/s.

      It also has half of the digital channels that the analog discovery has, 8 instead of 16, and doesn’t have the ability to send digital signals, only receive.

      It does have a spectrum analyzer but I couldn’t find information about a network analyzer so I’m assuming it doesn’t have that, which the analog discovery does.

      So it appears to have a scope, waveform generator, logic analyzer, and spectrum analyzer. Where as the analog discovery have a scope, waveform generator, power supplies, voltmeter, data logger, logic analyzer, pattern generator, static IO, network analyzer, spectrum analyzer, protocol analyzer, and a script editor if you need more customization.

      I guess more concisely, AD2 has more tools and higher sample rate, BitScope has higher bandwidth.

  2. “the largest buffer you can field for the scope is 16K per channel. That’s not much these days.” I bet you, it’s close to nothing!
    “For the price of the unit — especially adding in the BNC connectors — you could buy a pretty nice 2-channel scope” I would closer to a 4 channels scope, WITH probes, dedicated screen and buttons.

    The only interesting feature is the 14 bits channels for audio analysis but as you pointed it, with a closed and limited software I’m not in. Pity, with Sigrok compatibility it would be quite good though.

    1. A 4 channel scope for $279?? The 1054Z (not 1154Z as written) is still $399 (amazon.com). Maybe there a cheaper scopes but they need to be usable too…

      “the scope is pretty capable”
      Yeah… Of course it depends what you need, but 30MHz with 100MSPS is not so much… And because of this i’m not sure if the network analyzer will be very useful. The spectrum analyzer might be, it depends. And yes, 14bits can be nice of these sort of things but just to look at a signal you don’t need them imho. And 14bits is nice, but you have to look at the internals, how much noise is added to the signal from attenuators/… –>effective number of bits

      1. Ok, maybe closer than a Red Pitaya then, but again, what all theses USB/ETH devices lack is good software (at least non crashing), with many features, still usable in 10 years. Otherwise I think a 330€ (without VAT) 100MHz 4-channels Rigol is better to invest in.

        1. Red Pitaya is definitely a dev board not a tool like the Analog Discovery. Like I said before, try the software and you’ll find it doesn’t crash and has a ton of features, its free :). There’s a demo mode so you can explore the software without spending any money.

    2. Although the software is closed, the developer runs the scopes and instruments sections of forum.digilentinc.com. Almost every time someone has a complaint about the software, it’s fixed in the next revision.

      It also has a script editor so you can write your own tests.

      If you want to check it out without purchasing anything you can test out the software yourself for free. You can find the download at analogdiscovery.com/download. Then you can see for yourself if there are deal breaking limitations.

  3. It depresses me that we haven’t managed to move on from proprietary, platform-limited software for these devices. The better part of the “experience” you have with this piece of hardware is due to the capabilities (or lack thereof) of the software. It would be nice if more companies and users could support the efforts of e.g. sigrok to produce hardware-independent software stacks so that these hardware companies actually had to go back to competing on *hardware*.

    1. I wouldn’t define the software as platform limited, it can run on Linux, Mac, Windows, and some ARM devices. Unless you meant platform based in that it only runs on the Analog Discovery.

      The Analog Discovery 2 is built on a Spartan 6 FPGA, and has 14 bit ADCs, pretty good hardware as far as USB scopes go.

    2. Well I think the problem with competing on hardware as you say is going to be that this new generation of device is an FPGA meaning that the software IS the secret sauce here. Hard to compete solely on hardware when the hardware is an off the shelf commodity.

    1. No, as it is not really that ‘cheap’, and the unit myself and my dog evaluated indicates (mostly from noise floor) an ENOB of less than 11 bits. A good reference is the eevblog youtube video where the FFT, and supporting functions found on various o-scopes are evaluated.

  4. I’ve used both versions of the AnalogDiscovery (1 & 2) to build instrumentation for my lab (life sciences / biology). Its a pretty nice tool if you need to cram an arbitrary function generator and oscilloscope into a small enclosure. The learning curve is relatively steep, but the python API works alright once you get used to their function calls. Their API functions don’t throw exceptions so debugging is a huge pain. They are continuously updating their DLL files, which is great, but code written for the AD1 doesn’t work correctly for the AD2 and there is no guarantee that code written with their older DLL files (2.7.5) will work correctly when you install the newer ones (3.3.7+). There are also some weird qwerks in the newer versions, like the analog out channels defaulting to +5V out when they are initialized, rather than 0V.

    Both hate high frequency noise and will randomly drop the USB connection if you don’t take extreme measures to shield it. For example, it really hates the phidgets motor driver I use and you have to keep the two physically separated by a few feet. The device doesn’t auto-reconnect so you have to re-initialize it whenever this happens. The supplied USB cable has a ferrite bead, but I’ve had better luck with this one from Tripp Lite (https://www.amazon.com/gp/product/B008VOPCGY). Using the dedicated power adapter with the AD2 helps some, but doesn’t fully resolve this.

    Another major issue is that the analog out channels output a 1-10 ms waveform when the device is initialized or disconnected so you have to be careful what it is attached to when this happens. Its easy enough to build some digital logic to turn on the enable pin of an op-amp, but it would be great if this wasn’t an issue.

    Tech support is great and [attila] is pretty quick to get back to questions left on their forum. I’d definitely recommend this to anyone who needs a low cost DAQ and would rather avoid LabView.

    1. I think infinite recording is possible by placing the oscilloscope or logic analyzer instrument in “record” mode. This mode is rate-limited by the USB connection.

  5. I can understand a manufacturer not wanting to give their competitors free software by making it open-source, but the least they could do is offer an SDK so that I can write my own UI if I don’t like theirs.

    1. From the WaveForms 2015 reference manual:

      “SDK and Runtime
      The WaveForms installer includes the WaveForms SDK. The WaveForms SDK is a software development kit for creating custom applications and consists of user manual, examples in Python and C++, and library header file.

      The WaveForms installer also includes the WaveForms Runtime. The WaveForms runtime consists of a shared library (dwf) and device support files and is needed for running custom applications.”

  6. I have been looking for a recording scope that I can attach to speakers to see why my bass range turns to mush. Would this be a good one for looking at 48khz audio? The low sample count seems worrying.

    1. For audio you can get good results with cheap USB sound card. There is specific software fo speaker measurement and analysis that can use common sound cards for this purpose. So you don’t need AD2 for that…

  7. Have an AD2 myself, got it as a mini-lab-in-a-box for general electronics tinkering when I was away from my usual bench and space constrained for a couple of months earlier this year. Love it, worked perfectly for that purpose!

    One thing where I think it seems to fall short of its potential:
    HW wise it could easily replace your USB-serial adapter cable and bus pirate and maybe even do JTAG, but alas, the software doesn’t do any of that.

    @kaitlynfranz: any insights if there’s anything I’m missing here?

    1. You could always post on the Digilent Forum and see if [attila], apparently the main person who writes the Waveforms software, can get that sort of thing implemented. They seem to be pretty good at adding crowdsourced software feature requests into Waveforms.

    1. Looking at the AD chip you’ve chosen, which has a 11.1 kHz max sampling rate and 8 bit resolution, I don’t know what market this is targeted at. It’s too slow and too low-resolution for analog, and the only things slower are control systems and datalogging. How is this an improvement over a soundcard-based ‘scope, which would give you 16 bits at 48 or 96 kHz sampling rate?

      1. Thank you for the reply, I am aware of limitations of currently used AD and the speeds of arduino, it was a chip that I had at hand. I also think that 8bit can be converted to 16bit if needed – all explained on github, including encoding. Also there are FPGAs costing around $12 like https://www.xmos.com/support/boards?product=17441 with 4ADC onboard and other options available. This would also mean some new open source software that can be adapted to your needs.
        Thanks

  8. Hello OP or anyone who happen can help,

    I’m trying to find info for a very basic logic analyzer function.
    ?? Can the AD2 in LA mode capture synchronous data ??

    Background:
    There are 2 input pins on the AD2 label as Trigger (T1,T2). I tried to trace these on the reference schematic but it just end into a collective bus saying “To FPGA”. I was hoping this going to some clock pin on a component, but the schematic just ended there.

    I held back from purchasing the Saleae instrument, because they only sample data with internal clocks. This have the side effect of killing the search feature in a capture. For instance if one were to search for “A5A5” and the internal clock is running at 4 times the clock on the bus. This mean one would see “A5A5” 4 times before the next “A5A5” is found.

    Thank you so much for the article.

    Take care,

    linh

    1. Hi Linh,
      You can find tutorial including how to use the logic analyzer here: https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/start in the tutorials section.

      The Logic analyzer tutorial specifically is located here
      https://reference.digilentinc.com/learn/instrumentation/tutorials/ad2-logic-analyzer/start

      To use the trigger pins T1 and T2 you have to set the trigger source to External 1 or External 2 and then configure the trigger settings the way you want it to operate.

      Kaitlyn

  9. I think this product is way over-priced for what it is and how little hardware goes into it! It should be priced between $59 and $99. One would still need a computer to make this fucntion. Lets not forget that.
    If it was a stand-alone unit, it would be worth $300, but its not, so it’s not worth that much.
    Lets face it. This thing was crowd funded, so there was no investment to recoup, and the unit costs under $40 to manufacture. Why not price it under $100 so that it becomes ubiquitous with every hacker, hobbyist, and industry?
    This lack of vision, is due to greed.

  10. I have purchased an AD2 more than one year ago. Until now, have used it only as network analyzer, and it had been useful. But only for that, because always that I had need another tool, Digilent is closed and all proprietary, and I’m tired of closed and proprietary things.
    So, one thing is clear for me: no more digilent and the next toy will be a redpitaya.

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