DSLogic  - Page 1
Forum section: electronics / general

author: jancumps
author_rank: Unknown
timestamp: December 06, 2013, 08:37:21 am
content: This proposal for logic analyzer/oscilloscope is preparing a launch on KS:http://www.kickstarter.com/projects/dreamsourcelab/1909457015?token=48da08f5No affiliation.

author: Unknown
author_rank: Unknown
timestamp: December 07, 2013, 08:51:26 pm
content: The LA hardware looks like a good deal for the $50-$90 they ask. 100 MS/s (in 16 channel mode), 4 MS memory depth, trigger in/out, decent multi-level triggering with counters (though no protocol triggering), both state and timing mode. The specs also hints at two sets of threshold voltages for 1.8 V to 5 V logic. Whether they will actually deliver the hardware (at least they show actual hardware that looks like finished boards) and whether their software will be stable and of good quality is a different matter. From the pics it looks like a lot of the UI was inspired by the Saleae software.The oscilloscope feature seems to be completely vaporware (they state that they hope the community will develop the front-end, which is the hardest part). I don't see the appeal of the wireless sensor units, it looks like a fairly niche application to me. Are you really going to be sampling your temperature sensor with a logic analyzer?

author: jancumps
author_rank: Unknown
timestamp: December 07, 2013, 09:24:46 pm
content: They mention protocol triggering in a video. I'm also not that interested in the scope part. It's the logic analyzer that seems to be decent.

author: Marco
author_rank: Super Contributor
timestamp: December 07, 2013, 11:34:02 pm
content: Are they being disingenuous by saying "open source" a lot while not talking about the software or is it just an oversight?

author: MacAttak
author_rank: Unknown
timestamp: December 08, 2013, 02:21:43 am
content: Often, open-source projects that do crowdfunding campaigns will not release the source until they ship (or close to it). Sometimes the relevant source code and schematics (whichever is applicable) will be available from the start, but that is less common.

author: Marco
author_rank: Super Contributor
timestamp: December 08, 2013, 03:38:21 am
content: It's not so much the timing of release I'm concerned about, it's that they only say open source in relation to the hardware.

author: Stonent
author_rank: Super Contributor
timestamp: December 08, 2013, 05:48:34 am
content: "Arduion"

author: Rasz
author_rank: Super Contributor
timestamp: December 10, 2013, 07:21:47 pm
content: Open workbench logic sniffer with added- Cypress FX2 for usable transfer BW instead of original pathetic serial port emulation- ram chipLooks nice.

author: Unknown
author_rank: Unknown
timestamp: December 11, 2013, 01:19:28 pm
content: Quote from: Rasz on December 10, 2013, 07:21:47 pm- (what looks like) nice and finished software with actual support for its advanced triggering features

author: Rasz
author_rank: Super Contributor
timestamp: December 11, 2013, 02:41:10 pm
content: Quote from: alm on December 11, 2013, 01:19:28 pmI would rather see them work on Sigrok instead. Even if their software works, it will be abandoned after campaign ends :/

author: jancumps
author_rank: Unknown
timestamp: December 11, 2013, 03:17:11 pm
content: Quote from: Rasz on December 11, 2013, 02:41:10 pmDon't most kicstarters have the goal to start something that lasts longer than selling off the product they're launching?

author: biot
author_rank: Regular Contributor
timestamp: December 11, 2013, 03:43:43 pm
content: Quote from: Rasz on December 11, 2013, 02:41:10 pmIt is, in fact, sigrok. The GUI and underlying library were forked off some time ago from PulseView and libsigrok, respectively.We are currently working with the DreamSource Lab people to have them release their source sooner rather than later, as is of course required by the sigrok license (GPL). If everything works out, the changes they made can then be submitted back into sigrok, which means they will certainly be maintained.

author: Marco
author_rank: Super Contributor
timestamp: December 11, 2013, 10:51:54 pm
content: This makes the proposition a lot more interesting ... anyone familiar with any of the names behind this? Trustworthy?

author: jancumps
author_rank: Unknown
timestamp: December 11, 2013, 11:29:19 pm
content: I don't know the names.I think that what they propose is do-able. No super exotic parts like a thermal imaging device involved.

author: Kean
author_rank: Unknown
timestamp: December 12, 2013, 03:58:31 am
content: I'm a backer of this, but only for the starter kit. I don't think the wireless feature will be useful due to bandwidth. I guess it could be useful if you need some galvanic isolation.I really hope the software is up to scratch, and if as mentioned above it is enhancing sigrok (with appropriate contributions), then that will be very good.Kean

author: biot
author_rank: Regular Contributor
timestamp: December 16, 2013, 12:45:56 am
content: Just to follow up: the DreamSource Lab people have updated their kickstarter page to give credit to sigrok and the many other projects we depend on, and have released the source code. It's not in the form of a set of git patches -- more a dump -- but that works for now.The driver for their hardware is not included yet.

author: nctnico
author_rank: Super Contributor
timestamp: December 16, 2013, 03:01:49 am
content: The specs are a bit wild. High speed digital signals need lots of attention in the area of signal integrity. Despite the high sampling rate I wouldn't expect this board to be useful over several tens of MHz. A logic analyser needs proper probes just like an oscilloscope.

author: free_electron
author_rank: Super Contributor
timestamp: January 03, 2014, 06:26:26 am
content: That is my worry too. The front end consists of two stupid clamping diodes and a series resistance.That doesn't cut it for me.I'd like to see real programmable thresholds maybe in two banks of 8 bit each. And a better connector than the stupid 100 mil pinheader. Can we at least have a woven flatcable with proper termination ?

author: zapta
author_rank: Super Contributor
timestamp: January 03, 2014, 07:43:38 am
content: Quote from: Marco on December 07, 2013, 11:34:02 pm"All of our design files(software/firmware source code, schematic diagrams, board designs, and bill of materials) will be open source."

author: pinkysbrein
author_rank: Contributor
timestamp: January 03, 2014, 10:26:46 am
content: Quote from: free_electron on January 03, 2014, 06:26:26 amDoes the fpga have on die termination? How relevant is termimation though? Unless you have an active probe or a dedicated test port won't you usually rely on a high impedance input?

author: free_electron
author_rank: Super Contributor
timestamp: January 03, 2014, 02:42:21 pm
content: Very relevant ! If you screw up the edges of the signal you can kiss the timing corellation goodbye.It's not hard to make a nice terminated testpoint for a logic analyser. Two resistors and a small cap is all that is needed. Agilent publishes the schematic of their breakout cables.All you need is a small pod with a buffer chip driving the flatcable and a pigtail containing the rc network.Heck , you could even make the analyser with the idc connector as used by the agilent 6000 and 7000 series MSO's (or the 54645d).Those cables , i cluding pods and pigtails , can be had for 50$ on ebay.I would redesign the analyser to fit a nice sturdy metal box with that idc connector, a few sma connectors for a clock input and a trigger output.I knda like the design of this analyser because- it has real sample memory- it is fast- it can do sequence triggering- has good looking software that is not a kludge of 25 tools required to even view somethingI don't like it because- it is a bare, square , empty board not designed to fit anything- the input circuits are junk- it uses stupid 100 mil sideways pi headers (fro. What i can tell SMT nonetheless. A very bad idea as this is a connector that will be under substantial mechanical stress due to frquent plugging and unlkugging so the chances of ripping it off the board are much higher than with a thru-hole- it has no box. I dont want bare boards dangling on a testbench causing shorts and other misery with the item under test. Test equipment must come in a case.

author: Marco
author_rank: Super Contributor
timestamp: January 04, 2014, 08:00:08 pm
content: Quote from: free_electron on January 03, 2014, 02:42:21 pmYes ... but reading up on it, it's not really termination.The logic analyzer inputs for those Agilent PODs seem to have around 10K input impedance (and 100 pF capacitance in the probe cable) forming a 10x divider with the RC networks in the probes or on the board. It makes sense, but needs a lot more circuitry than just termination.

author: Jon86
author_rank: Frequent Contributor
timestamp: January 04, 2014, 08:14:46 pm
content: Quote from: free_electron on January 03, 2014, 02:42:21 pmThe best thing about this project is its simplicity. No stupid showy enclosure, no annoying proprietry connectors. Start adding all that stuff in and the cost is going to be through the roof.

author: Marco
author_rank: Super Contributor
timestamp: January 04, 2014, 10:43:04 pm
content: How would you cheaply build a high speed logic analyzer input stage for a 10x probe any way?

author: eev_makr
author_rank: Newbie
timestamp: January 08, 2014, 06:25:40 pm
content: guys, all I can say for now: be prepared for another kickstarter launch in 10 days from now, which will solve your questions in a more professional approach, offers more and... comes even at a lower cost (especially for the 100 early birds)by makers for makers; as a true kickstarter should be

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: January 10, 2014, 06:32:53 pm
content: I'm in, just so I can replace my open bench logic sniffer. looks like they should hit their second goal and upgrade the memory from 64mbits to 256mbits which will make it a really nice replacement for the OLS

author: electronic_eel
author_rank: Regular Contributor
timestamp: January 10, 2014, 06:40:10 pm
content: Hi,could anybody enlighten me about the specs of the logic analyzer:In their Spartan6 strech goal announcement they claim 400MHz @ 4 channels. This matches the 1600Mbps Bandwidth they write about.But below, under "Interface for logic analyzer" they have:CH15 ~ CH0:Maximum Input Bandwidth: 50MHzCLK, TI, TO:Maximum state clock: 50MHzNow how does this fit together? I want to sample fast serial signals, so I'm interested in the 400MHz @ 4 channels they claim. Don't care about the scope stuff, I have a decent scope.

author: Marco
author_rank: Super Contributor
timestamp: January 10, 2014, 08:10:54 pm
content: Lets say a 1 feet ribbon cable and lets be optimistic and posit 10 pF capacitance ... at 400 MHz a non active 1x probe with such a cable would load your circuit with <40 Ohm capacitive impedance. At these speeds you really need either active probes or attenuated probes and thus an input stage capable of distinguishing attenuated logic levels.

author: electronic_eel
author_rank: Regular Contributor
timestamp: January 10, 2014, 09:02:18 pm
content: I see. Thanks Marco.Why do they then go the FPGA&Mem route? Why not just take a FX3 and let the PC do all the heavy lifting?

author: Marco
author_rank: Super Contributor
timestamp: January 10, 2014, 09:44:05 pm
content: Dunno, but that question is relevant regardless ... even your 4x400 Mbps could easily fit across USB 3.0.

author: rrpilot
author_rank: Newbie
timestamp: January 10, 2014, 09:58:22 pm
content: Quote from: electronic_eel on January 10, 2014, 09:02:18 pmI don't think this product is designed to feed the data to your PC in real time. Basically it's going to trigger, start recording, fill up memory and then slowly (in relative terms) transfer the data to the PC. This is how other high-sample rate logic analyzers function. I worked with one from Agilent that used Firewire and it worked in the same fashion. Since they mention using USB 2.0, there's no way the PC interface could handle the data.

author: electronic_eel
author_rank: Regular Contributor
timestamp: January 10, 2014, 10:51:00 pm
content: Yeah, this is what I was talking about. They trigger & record till the mem is full. And then they transfer over usb 2. So all trigger logic has to be inside the FPGA. If you wanted real protocol triggers (which they don't have and don't claim, but are extremely useful), you'd have to code that up in VHDL and try to fit it in the FPGA.That is why I think using an FX3 and USB 3 would so be much better: the la could be stupid and just transfer all data in realtime to the pc. Using a decent processor for compression, enough ram and a big ssd you could sample all day. A regular pc software, which is easier to write than VHDL and more versatile, could then search for the data you are looking for. No need for intelligent triggers at all.This is what makes the saleae so simple and still very useful. Using the FX3 would just take it to a new level.

author: PlainName
author_rank: Super Contributor
timestamp: January 11, 2014, 02:25:53 pm
content: QuoteThe Saleae is overly simple: triggering is on levels and an edge only - no protocol stuff, no sequencing, nothing else. Years ago, when it first came out and I bought one, I asked for the triggering to be auto-armed after capture (so you didn't need to keep hitting the capture button), but it's never shown up. You could do the fancy PC stuff in a 74 series logic chip so far as i can see.And... if the answer is a PC and the stumbling block the LA->PC link, why not do away with the link and shove a PC right thereinthe LA? A RPi would fit OK, wouldn't it? Do whatever the hell you want and dribble the result out via a web page if you wanted to be perverse, but that web page could be fronting serious real-time cleverness. More likely, you'd dribble the result over a slow bus to some PC GUI app, andthatwould be the slow and simple thing it should rightly be.

author: Kean
author_rank: Unknown
timestamp: January 11, 2014, 02:38:59 pm
content: Quote from: dunkemhigh on January 11, 2014, 02:25:53 pmThat is what the Red Pitaya is doing (edit: will do...). In fact it is (edit: will be...) capable of a lot more that the DSLogic, but at a higher price point.http://www.kickstarter.com/projects/652945597/red-pitaya-open-instruments-for-everyone

author: PlainName
author_rank: Super Contributor
timestamp: January 11, 2014, 02:59:02 pm
content: You pays your money and takes your choice

author: Kean
author_rank: Unknown
timestamp: January 11, 2014, 03:11:30 pm
content: Or, if you're like me - you hedge your bets and throw money in both directions!

author: PlainName
author_rank: Super Contributor
timestamp: January 11, 2014, 03:22:23 pm
content: Another man with an accumulation of shelf-ware

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: March 26, 2014, 03:40:50 pm
content: looks like the dslogic is shipping with its nifty little aluminium case this week! right in its stated delivery window. nice to have a kickstarter come in on its said schedule!

author: jancumps
author_rank: Unknown
timestamp: June 08, 2014, 06:50:02 am
content: ... anyone bought one?

author: Kean
author_rank: Unknown
timestamp: June 09, 2014, 12:16:21 am
content: Quote from: jancumps on June 08, 2014, 06:50:02 amI got mine - just the starter kit (core board), but in the nice aluminium case.It seems to work fine, and the software is reasonable (almost but not quite Saleae quality). I haven't yet done any serious measurements with it to verify timing and bandwidth.It also shipped in better than average packaging for a Chinese product.

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: June 09, 2014, 04:33:33 pm
content: yep. nice case it came in, as stated above, it was packaged like a real product not just a padded bag!i build the software from github source. it would be nice to see it integrated back to sigrok but for now its not. builds and seems to work just fine. under linux you need to run it as root tho (for me at least) so it can access the usb device and upload its firmware each time it runs.

author: motocoder
author_rank: Unknown
timestamp: June 17, 2014, 07:52:45 am
content: Quote from: BloodyCactus on June 09, 2014, 04:33:33 pmYou can almost certainly fix the root requirement with a udev rule to set the permissions on the USB device.

author: JohnSL
author_rank: Regular Contributor
timestamp: July 13, 2014, 10:39:01 pm
content: I just setup my DSLogic box today, but I'm not sure how to get it to work. I've never used a logic analyzer before (I have used oscilloscopes), and I couldn't find a manual anywhere. I installed the software and drivers, and then fired up the DSLogic application. It found my DSLogic box. I also hooked up the ground, and channel 0 and 1 to a circuit that I'm playing around with. What I expect to see is that when channel 0 drops to 0V, channel 1 will drop a short time later. I want to see what this delay is. Right now I'm driving my board with a 1 Hz input signal.I set DS Logic to use 1k samples @ 10Khz. I'm not sure what this means, as there is no manual. Does it mean that I need 1,000 samples before anything will show up on the screen? Right now I see the big round logo with three circles that alternately light up. I don't see any traces on any of the channels.

author: miguelvp
author_rank: Super Contributor
timestamp: July 13, 2014, 10:49:03 pm
content: Quote from: JohnSL on July 13, 2014, 10:39:01 pmI don't have a DSLogic box or a logic analyzer for that matter, but I can explain what is happening to you.10KHz sampling rate is 10,000 samples per second and you are capturing 1K or 1,000 so you are just getting one tenth of a second or 0.1 seconds. Since your board is running at 1 Hz (1 cycle per second) then you won't see anything.So you need to lower the sample frequency to be lower, or increase the number of samples captured to be higher than the sample frequency, or change your board to run quicker than 1 Hz.I hope that makes sense.

author: JohnSL
author_rank: Regular Contributor
timestamp: July 14, 2014, 12:43:43 am
content: Quote from: miguelvp on July 13, 2014, 10:49:03 pmYes, thanks, that makes sense. I also tried 16 M samples at 10 KHz (that's the slowest sampling rate), and I still don't see anything. It just keeps showing the dancing dots that seem to indicate it's collecting data. When I click the stop button and zoom out, I see the time range as being 1.64 seconds. But I still don't see any traces.So I'm wondering if perhaps my box isn't working correctly.

author: madworm
author_rank: Frequent Contributor
timestamp: July 14, 2014, 12:48:28 am
content: Look at the trigger settings!You will most likely have to set up a trigger condition. E.g. channel 0 going from LOW to HIGH or something along those lines.

author: JohnSL
author_rank: Regular Contributor
timestamp: July 14, 2014, 04:47:45 am
content: Quote from: madworm on July 14, 2014, 12:48:28 amI tried several different ways to set a trigger, and I still don't see any waveforms showing up. So I've sent an email to their tech support. I was hoping someone would give me the "magic sauce" I was missing so I could get it working this weekend. Oh well.

author: elektrinis
author_rank: Regular Contributor
timestamp: June 22, 2018, 03:52:00 pm
content: Fast forward 4 years and...Anyone use DSlogic now? They also have a DScope and the software looks okay. I wonder if it is safe to buy now.Could not find any reviews of DScope so far.Also there seems to be at least 3 versions of DSlogic available:1. 2.5mm pitch inputs2. 2mm pitch inputs with 256k memory3. 2mm pitch inputs with 256M memory

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 30, 2018, 07:48:04 pm
content: Just had a look on their website.Almost all products are "out of stock".Hackaday sold it for a while, but it seems that a lot of products are dissapearing from Hackaday and they might be phasing out the "shop" on their site.From what I've heared DSlogic has modified the (old) Sigrok / (Pulseview) source a lot and in ways that are almost impossible to port back.For a logic Analyser I use the cheap (EUR 5) "24m 8ch" boxes from Ebay / Ali / China with Sigrok & Pulseview. (Any Cypress Cy7C68013A development board will do).These EUR 5 LA's are plenty for debugging microcontroller stuff such as SPI UART, RS485 and a lot of other serial protocols. I've even captured low speed USB with that box and Pulseview has decoders for it.A general development board for the Cypress supports 16 channels, but does not have the extra input protection that the logic analyser boards have.I will gladly buy a "better" logic analyser, especially if it is oficially supported by Sigrok and it means pushing some money in their direction.

author: knapik
author_rank: Regular Contributor
timestamp: July 01, 2018, 07:12:14 am
content: I had been looking at these logic analysers as they seemed like a good price for something to use with Sigrok & Pulseview. However, if what you say is true, that you can't really use a new version of Sigrok with it, that does change my perspective on it quite a bit.

author: vltr
author_rank: Contributor
timestamp: July 01, 2018, 09:06:41 pm
content: I have a DSLogic and when it works its quite nice. The problem with no development has been that drivers are a huge problem for windows users. The driver is not signed and doesn't appear to work with windows 10 at all. Sigrok folks seem to have added it and i've gotten it to work once or twice under linux, but every time i pull it out it seems something software needs attention and troubleshooting. I would personally not buy one again, and I only use it when my $10 ebay special knockoff doesn't have the spec/enough channels just because its not worth the trouble playing will it work today.

author: elektrinis
author_rank: Regular Contributor
timestamp: July 02, 2018, 05:20:59 am
content: Quote from: vltr on July 01, 2018, 09:06:41 pmThis is the type of feedback I was hoping for. Thank you.I guess their DScope is the same?I bought a scope-LA combo from LabNation. Pretty decent device, nice app for touchscreen - so far they are the only ones who managed to make the interface really user friendly. At least for moving traces around, zooming, adding measurement lines, etc.Negatives:* Pretty basic though, lacking many functions, like for testing in production environment, many decoding parameters are missing. Also that light green/blue trace color.. What's up with that? Unable to see it if used outdoors on a tablet. Also GUI DPI scaling works very poorly, some developers are still struggling with that a lot.* There was no update for Windows version for some time now. I wonder how the company is doing.* Enclosure is really amateurish and non-comparable with any of well known USB devices, including chinese DSlogic. You can quickly see they are a very small company, unable to do proper molded plastic enclosures.

author: Jan Finkel
author_rank: Newbie
timestamp: July 02, 2018, 09:39:33 am
content: Quote from: vltr on July 01, 2018, 09:06:41 pmThanks for your feedback, really usefull

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 05, 2018, 05:40:55 pm
content: I bought the first revision of the DSLogic tool when it got released. Nice but too limited in my experience. The input bandwidth is very limited, more than I expected. I wanted to use it to inspect sync. serial busses @50 Mbits/s and it was unusable for that. The sample rate of 400Msa/s sounded good enough, but the input bandwidth is just far too limited. For more modest needs it's ok but frankly it got stored in a drawer and I never use it anymore.

author: Marco
author_rank: Super Contributor
timestamp: July 05, 2018, 05:51:40 pm
content: They had some input filtering on the old version which they removed on the newer ones ... that said, it doesn't seem like you know whether you're buying old or new ones.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 05, 2018, 05:53:30 pm
content: Quote from: Marco on July 05, 2018, 05:51:40 pmOh, thanks for the info. Do you happen to know whether it's possible to remove the filtering on older versions? I have already opened it so I don't mind tinkering with it.

author: Marco
author_rank: Super Contributor
timestamp: July 05, 2018, 05:59:09 pm
content: Dunno, it was described on the following video ... shouldn't be too hard to mod.PS. I wish I could link youtube vids without inlining, am I missing something?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 07, 2018, 05:02:51 pm
content: I just had an idea about Logic Analyser probing.With a bit of hot snot you can glue a (through hole) 74xx541 or a buffer for whatever signal levels you use onto the PCB you are testing in "dead bug" style.On one side you have plenty of grip for even the cheapest logic analyser probes, and on the other side you have 8 inputs and you can relatively easy solder lacquered wires between the probe points and the buffer chip.

author: pigrew
author_rank: Frequent Contributor
timestamp: October 21, 2019, 04:14:08 pm
content: I recently purchased a DSLogic Plus where the probe compensation components are located closer to the probe tip (very good). From the outside, the new probes look the same as the old probes.Attached are some poor X-ray images. They show 2-layer PCBs, and the expected R||(R+C) network at the end of each probe (instead of at the LA connector like in previous revisions).

author: amspire
author_rank: Super Contributor
timestamp: October 21, 2019, 10:41:32 pm
content: The circuit for this probe tip is on the Sigrok site:https://sigrok.org/wiki/File:Dreamsourcelab_dslogic_plus_probe_circuit.png