USB Logic Analyzers

[smbaker]

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz. Checking ebay, I can find the following:

* Salae 8-channel 24 Mhz for around $6
* Salae 16-channel 100 MHz for around $43
* SeeedStudio 16-channel 100 MHz / 4-channel 400 Mhz for around $75

I'm thinking the 16-channel 100 Mhz products fit my use case with room to expand. The 8-channel 24 Mhz is appealing solely because at $6 if I do something stupid and ruin it, I can throw it away and not feel bad.

Any experiences with these products? is the software decent?

Scott

[ataradov]

$6 Salae are clones, otherwise they work perfectly, if you don't feel guilty about this kind of stuff.

[trevwhite]

You can get the usbee clones as well and pay for the software license

Sent from my SM-G950F using Tapatalk

[Gabri74]

I second buying a cheap Chinese logic analyzer as your first analyzer and using sigrok, perfectly legal and moral :-)

I think that also buying an DSLogic clone and using their original software is somewhat moral because basically the cloned sigrok PulseView, refined some future and refused to release source codes (which the where obliged to bye the GPL) for a long time.

See this great video for a primer on sigrok and a comparison of various cheap ebay logic analyzers (done by the main PulseView developer):

[MrW0lf]

Are you taking into account that 24MHz one sampling rate will drop to nothing when all 8 enabled may struggle on full rate (see OTL video)? 16-ch version will drop also of course but to less appalling levels.
Due to TEO syndrome I have 6 devices that could be used for this kind of activity and was thinking to do review maybe but struggle to find motivation because most comments will be probably "just buy $6 one"

[abraxa]

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz.

I suggest you get a 8ch one for $6 and use PulseView with it. That way, you can figure out what you like/don't like and what exactly you need, should you need something bigger.

Are you taking into account that 24MHz one sampling rate will drop to nothing when all 8 enabled?

How so? The Cypress FX2 always transmits 8 bits per sample (except for when it's told to send 16 bit), so enabling/disabling individual lines doesn't change anything. The main thing affecting the sample rate is the USB connection - a cheap/bad USB cable makes the connection unreliable, resulting in unsuccessful data acquisition.

[MrW0lf]

How so? The Cypress FX2 always transmits 8 bits per sample (except for when it's told to send 16 bit), so enabling/disabling individual lines doesn't change anything.

Ok, thats the one I do not have - seem have to buy all of them to stay informed Thought it is similar to others in that regard. I just bought 100MHz one after watching OTL video which showed that $6 one wont manage 24MHz reliably. Overall I find massive oversampling useful because it works sort of scope then and will give timing info.

[TK]

For retrocomputing projects you are better with 32 channels: 16 for address bus, 8 for data bus and 8 for control signals.  8 channel logic analyzers are useful for serial decoding.

I know modern USB logic analyzers are more practical.  I have one but I also got an old HP 1670D that can do timing and state analysis and with the right information, you can also do microprocessor (Z80, 6502, 6800, 68000...) inverse assembly.  It does not take much bench space like the 16500 or 16702B.  The 1670G is more modern with color LCD screen, but a little more expensive.  You can get 1670D in decent shape with all the cables and some probes for around $150 on eBay.

[MrW0lf]

For retrocomputing projects you are better with 32 channels:

Aha, have one for that:
http://store.digilentinc.com/digital-discovery-portable-logic-analyzer-and-digital-pattern-generator/

32-channel digital logic analyzer (1.2…3.3V CMOS, 8 channels at 800MS/s*, 16 channels at 400MS/s*, and 32 channels at 200MS/s)
...
*Note: to obtain speeds of 200MS/s and higher, the High Speed Adapter must be used.
...
Setting the voltage to 3.3V, 5V logic inputs are tolerated but the input threshold is 1.42V. LVCMOS 3.3V output signals are compatible to most external logical circuits supplied with 5V.

But no doubt proper boat anchor would squash it

[technogeeky]

I second buying a cheap Chinese logic analyzer as your first analyzer and using sigrok, perfectly legal and moral :-)

I think that also buying an DSLogic clone and using their original software is somewhat moral because basically the cloned sigrok PulseView, refined some future and refused to release source codes (which the where obliged to bye the GPL) for a long time.

See this great video for a primer on sigrok and a comparison of various cheap ebay logic analyzers (done by the main PulseView developer):

That guy makes some excellent videos. Really incredibly well put together videos.

[smbaker]

After watching the video, I'm considering the DSLogic, as it seems to offer some advantages over the saleae clones. Buffering seems useful, I like the idea of being able to get ~ 100 Mhz bandwidth at full channels. Even if I'm operating at a maximum of 16 Mhz bus speed on my projects, the oversampling would allow me a better shot at detecting timing issues.

[0xdeadbeef]

I have a DSLogic (Pro), well actually I have two of them and the hardware is great, but keep two things in mind:
1) There are different versions sold on eBay where some use a weird high density probe connector which means that you can't connect normal jumper wires to the device and are screwed if the probe cables break one day.
2) The project/site is effectively dead and the windows driver is not signed. Which means you need trickery to force Win10 into accepting an unsigned driver and you might as well not be able to install the drivers at all one day.
Apart from that, it's pretty nice. The trigger options are pretty limited and weird but at least the SW is reliable and the protocol decoders work reasonably fast (in the 1st SW version I used, they were like 200 times or so slower).

BTW: it's a shame that Ikalogic seems to be incapable of releasing a successor to the ScanaPlus which is discontinued and no longer available. After the planned release date for the ScanaPlus-X has elapsed some months ago, they removed the product page and only mention it as "coming soon".  I always liked my ScanaPlus and still like it despite of some reliability issues but I kinda lost my faith in Ikalogic after releasing one weird product after the other, never fixing the issues in ScanaStudio 2.0 Beta and finally shutting down the forums (some years after crippling them with some fancy Web2.0 nonsense). Actually I kinda assume the company will fold soon. Hope to be wrong though.

[Gabri74]

I have a DSLogic (Pro), well actually I have two of them and the hardware is great, but keep two things in mind:
1) There are different versions sold on eBay where some use a weird high density probe connector which means that you can't connect normal jumper wires to the device and are screwed if the probe cables break one day.

By coincidence I was just discussing about different DSLogic versions on the sigrok irc channel few minutes ago. After a boring ebay/aliexpress session this is what I discovered:
- the DSLogic Pro is the same as the DSLogic (original) with adjustable  input levels and are V1 versions
- the Pro seems no longer produced/available
- there are two V2 models with new connector: the Plus and the Basic.
- the Plus has 256MegaBits of SDRAM and is listed on ebay with different titles, like FPGA+Buffer or FPGA+SDRAM for about 100€.
- the Basic model has only 256KiloBits of ram and is listed only as FPGA or SpartanFPGA and is about 60€.
- found also another model priced at 87€ with 16 Mbits of memory... but I think It's a typo

So be careful and read with care all the informations on the listing. Hope it helps.

[MrW0lf]

This one has 2GigaBits:

Look at views - 29 in 10 days! Some interesting material in other parts (total 7). I seriously fail to understand world of LAs. For example Sigrok/PulseView seems all the rage architecture wise yet look Google Trends:
https://trends.google.com/trends/explore?date=today%205-y&q=saleae,sigrok,pulseview

[0xdeadbeef]

- the Pro seems no longer produced/available
- there are two V2 models with new connector: the Plus and the Basic.
- the Plus has 256MegaBits of SDRAM and is listed on ebay with different titles, like FPGA+Buffer or FPGA+SDRAM for about 100€.
- the Basic model has only 256KiloBits of ram and is listed only as FPGA or SpartanFPGA and is about 60€.

Well, I have an original Plus and a Plus with the new connector. Both have 256MBits of RAM and behave identically.
I prefer the old connector by far as it's much more convenient and robust. Maybe the new one is better suited for high frequencies but I'm not totally convinced it is.

[schmitt trigger]

Guilty? Guilty for what? Nobody forces you to use Saleae software. Sigrok is there for you, free of charge, open source.

On the other hand, if one does indeed use Saleae software, I would purchase the original stuff.
That is what I did.

[Frddy]

Hey guys I just wanted to chip in regarding the DSLogic.. I recently bought one from ebay which I hope arrives soon.. It should have the 'newest'? style of connectors as in this video:
.

Which looks pretty nice. Atleast that's what I'm hoping for & is what the seller told me.. It was a kit with a separate oscilloscope (microUsb connector appearantly) for 80 USD.. (Right now the same ad is at 180 USD..)

The seller reports "Based on Xilinx Spartan - 6 FPGA + SDRAM", "sampling depth of 16 M * 16 channel"
When I get it I can report back to ye and see what I got.. I'm rather curious myself.. Probably takes another week or two.

[0xdeadbeef]

Hm, that's a different style of probes again but the onboard connector looks like the original spacing.
Also the USB controller is different than the original one (Cypress CY7C68013A).
Looks like someone creates a new version every year or so. It's just a shame they put so much more effort in the hardware than in the software.

[smbaker]

I have a DSLogic (Pro), well actually I have two of them and the hardware is great, but keep two things in mind:
1) There are different versions sold on eBay where some use a weird high density probe connector which means that you can't connect normal jumper wires to the device and are screwed if the probe cables break one day.
2) The project/site is effectively dead and the windows driver is not signed. Which means you need trickery to force Win10 into accepting an unsigned driver and you might as well not be able to install the drivers at all one day.

Thanks for the note, I was aware of the two different styles of connectors having seen them in eBay listings (some listings even confusingly showing both styles in the same listing), but I wasn't aware of the driver issues. I don't particularly want to buy a product that's no longer supported and will be giving me endless compatibility problems as Windows marches ever forward.

I think I'm going to go cheap, buy the Saleae clone 16 channel, then once I have my feet wet with that, I can look into something more expensive that will be supported.

[0xdeadbeef]

There seem to be actually three connector types now where the latest ones look actually the best from the pictures I saw.
It's bad news that the newest version seems to be sold with and without the 256MBit SRAM where the version without SRAM costs as much as the version with SRAM cost one or two years ago.
IMHO removing the buffer RAM is a really bad idea and anybody interested in buying this thing should be really careful not to be tricked into the version without RAM.
And yes the unsigned driver could very soon turn into a showstopper. Actually, as soon as we upgrade to Win10 at work, I won't be able to use the DSLogic there. Even if I could install an unsigned driver driver there (dunno if this will be possible at all in a corporate environment), I guess I won't even try as this will for sure violate the company's code of conduct.

[technogeeky]

There seem to be actually three connector types now where the latest ones look actually the best from the pictures I saw.
It's bad news that the newest version seems to be sold with and without the 256MBit SRAM where the version without SRAM costs as much as the version with SRAM cost one or two years ago.
IMHO removing the buffer RAM is a really bad idea and anybody interested in buying this thing should be really careful not to be tricked into the version without RAM.
And yes the unsigned driver could very soon turn into a showstopper. Actually, as soon as we upgrade to Win10 at work, I won't be able to use the DSLogic there. Even if I could install an unsigned driver driver there (dunno if this will be possible at all in a corporate environment), I guess I won't even try as this will for sure violate the company's code of conduct.

I don't know about the driver problems, but I wanted to comment:

1. As to the comment in your previous post, the style of connectors with the individual ground pins per channel are demonstrated to help at high frequencies (as per the video posted above: ). I won't say that his video proves this, it merely demonstrates this.

2. I totally agree. If that unit ships without RAM, then the bandwidth statement becomes totally bogus. There is no way to know what bandwidth you would get with this device in "streaming" mode (because nobody has characterized the overheads), but I bet it's not much. Maybe if this device had a USB3 interface, it could be useful without the RAM.

I don't understand the nomenclature anyway. I don't see a "plus" version at all anywhere on their site.

[cdev]

 Sealae have a very nice product - its built like a tank - and very pretty with its rainbow cables and pod.. The grabber clips it comes with are expensive ones, too. the case is really nice looking.

Was it the first of its kind? No, it wasn't the first of its (Fx) kind.

Was Saelae it the "original" FX based LA? No, not really. 

Was the FX development board for sale before the Saelae Logic was? Yes.

Was it an innovative idea.. Yes. the idea of downloading the program into the hardware was a brilliant idea,
....of some engineer at Cypress.

[Mr. Scram]

Sealae have a very nice product - its built like a tank - and very pretty with its rainbow cables and pod.. The grabber clips it comes with are expensive ones, too. the case is really nice looking.

Was it the first of its kind? No, it wasn't the first of its (Fx) kind.

Was Saelae it the "original" FX based LA? No, not really. 

Was the FX development board for sale before the Saelae Logic was? Yes.

Was it an innovative idea.. Yes. the idea of downloading the program into the hardware was a brilliant idea,
....of some engineer at Cypress.

Did Cypress develop their software too? As Dave has shown, a lot of products are let down by the software, even very expensive ones. Saleae seems to do this very well and considering how many have failed, it has taken non-trivial effort to do so.

[cdev]

I use Sigrok (pulseview) and it works great.  Its bright and easy to read. It does the jobs I need it to do.

I don't feel deprived at all.

Sealae have a very nice product - its built like a tank - and very pretty with its rainbow cables and pod.. The grabber clips it comes with are expensive ones, too. the case is really nice looking.

Was it the first of its kind? No, it wasn't the first of its (Fx) kind.

Was Saelae it the "original" FX based LA? No, not really. 

Was the FX development board for sale before the Saelae Logic was? Yes.

Was it an innovative idea.. Yes. the idea of downloading the program into the hardware was a brilliant idea,
....of some engineer at Cypress.

Did Cypress develop their software too? As Dave has shown, a lot of products are let down by the software, even very expensive ones. Saleae seems to do this very well and considering how many have failed, it has taken non-trivial effort to do so.

[0xdeadbeef]

As to the comment in your previous post, the style of connectors with the individual ground pins per channel are demonstrated to help at high frequencies (as per the video posted above:

This is actually the only part of the probes that never changed and which is one of the reasons I said the hardware is great.
What changed is the connector of the probes to the DSLogic PCB. It started as a plain male header but all the probes together in one big female connector. The 2nd iterations was some weird fragile high density connector. Finally they seem to have a female connector on the PCB now and the probes can be divided in groups of 2x2 or so. I very much like that you don't need to connect all probe cables in the newest version and it's great that they moved pack to standard pitch. While I don't fully get why they made the PCB connector female, I still think this is the best connector type of the three types used.

I don't understand the nomenclature anyway. I don't see a "plus" version at all anywhere on their site.

Yeah, the DreamSourceLab site only knows DsLogic and DsLogic Pro where the DsLogic was the original Kickstarter design and the Pro was the commercial version with adjustable threshold levels.
So my two devices are both Pro, not Plus. As this thing is open hardware and software, I'm unsure if the new versions are really designed by the same people or if somebody else continued where they left off.
Anyway, the Plus seems to be a Pro with different USB chip and connector and the new non-Plus is a crippled version without RAM while the original non-Pro just didn't have the adjustable threshold.

[cv007]

After reading this thread and looking at some videos, I decided to try the DSLogic Basic (my price range ~$70).

I purchased from eBay- it was listed as used(but new) from a seller that had an actual picture of the device (and the box which shows it was a Basic). Every other ebay seller of this device don't seem to know what they are selling, so you may end up getting an older model (I wanted the newest connectors). Anyway, I decided to be cheap (Basic model) and was hoping the 'upgrade' to the Plus model would be an easy fix if needed. It is a bit of a strange deal-  DreamSourceLab apparently makes these, but does not list these new models anywhere on their website although supported in their software.

The software for the Linux version has to be compiled, so I used another temp PC to do the build (my standard practice when something requires a ton of development tools to do the build- no need to screw up my main PC). The build went ok, and I transferred the files to my main pc. The app seems to work ok and looks like it will do the job.  The backup plan was to use sigrok/Pulsview. After playing around with this for a while, I'm thinking I should have had a logic analyzer a long time ago.

I'm not sure if I need anything other than the streaming mode, but I think the 256Mbit can easily be added so why not. Looking at the board, the only missing item is the 256Mbit sdram, and that part is $3 from Mouser. So, I can add the sdram, but am unsure what I should do on the software side.  The best way would be to get the pid changed to the Plus model, but I'm not sure how. The easy way I think would be to just recompile the software, changing the description structure of the Basic to match the Plus- then it will think its the Plus model (which, except for the pid, it will be). Any better ideas?

[Gabri74]

I've done exactly the same in the past few days :-D

Just yesterday I received my basic, compiled source code for Linux just for testing because my goal is to use it with sigrok/pulseview.
Obviously first thing I did was to open it. I took several pictures of the board to compare it with the pro which are on the sigrok wiki.

I've received edit permissions on the sigrok wiki and plan to add a page with information about the basic which is not listed.

I'm also planning on adding the sram to upgrade it to a plus, but I guess we need to modify the VID:PID data which are presumably stored in the EEPROM.
As soon as I'll have time I'm planning to dump the EEPROM and try to change VID:PID: this should suffice  to it be recognized as a Plus and to allow the correct
firmware to be uploaded.

As of today I was not able to use it with sigrok: I've extracted the FPGA firmware from the binary blob using those instructions on the wiki but neither sigrok-cli nor PulseView recognized it.
I think the support for the basic was added recently only in git, not in the stable versions tarballs (which I'm using for now).

I'll keep updating this thread with mi progress.

[cv007]

So, I can add the sdram, but am unsure what I should do on the software side

After looking at the code (which is almost readable to me, in contrast to the build system), its looks like its far simpler than I was thinking.

Make backup copies of the DSLogicBasic.fw/.bin files, copy the DSLogicPlus.fw/.bin files to DSLogicBasic.fw/.bin files (overwrite)
Unplug device, plug back in, the Plus firmwares will be uploaded. Of course without the sdram, neither stream or buffer modes returns any data, but the device will show as a DSLogicPLus. It appears the pid only determines which firmwares to upload, and after that it no longer matters.

I'm not sure about sigrok/Pulseview, but I imagine the same will work.

[cdev]

Check out https://opentechlab.org.uk

There are a bunch of useful videos on low cost logic analyzers and using them with pulseview. There is some stuff on DSLogic devices. The author of pulseview is a fan of their hardware. In a YouTube video he discusses their LA.

https://opentechlab.org.uk/videos:009:notes

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz.

[Frddy]

Hey ya'll.. So mine arrived today as well! It is the same as in the pictures, but is a basic model with no ram unfortunately. In spite of the fact that the ebay add mentions a buffer mode with 16x16.. Still not sure if I should file an ebay complaint or not.. Given I kind of expected this..

Anyway, looks like we're doing great working towards upgrading it to a Plus model! Obviously I want to do the same adding RAM. I did spot something now that I've actually got mine: the 'probes' are not the same as in the video. They're actually not a coax-style, but rather have 5 long wires to each probe per connector: 1 ground and 4 signal wires.. 

...
I'm not sure if I need anything other than the streaming mode, but I think the 256Mbit can easily be added so why not. Looking at the board, the only missing item is the 256Mbit sdram, and that part is $3 from Mouser. So, I can add the sdram, but am unsure what I should do on the software side.
...

Only $3 ? It'll cost me atleast three times that from Farnell

So, I can add the sdram, but am unsure what I should do on the software side

After looking at the code (which is almost readable to me, in contrast to the build system), its looks like its far simpler than I was thinking.

Make backup copies of the DSLogicBasic.fw/.bin files, copy the DSLogicPlus.fw/.bin files to DSLogicBasic.fw/.bin files (overwrite)
Unplug device, plug back in, the Plus firmwares will be uploaded. Of course without the sdram, neither stream or buffer modes returns any data, but the device will show as a DSLogicPLus. It appears the pid only determines which firmwares to upload, and after that it no longer matters.

I'm not sure about sigrok/Pulseview, but I imagine the same will work.

Hmm. This does not appear to work for me on Windows 10. When I remove the DSLogicBasic the device no longer initializes ,red led stays red. (Confirming that it uses the file) When I copy the DSLogicPlus as DSLogicBasic, it still shows up as "DSLogic Basic" in DSView.

Btw, what is the RAM actually used for ?

[cv007]

They're actually not a coax-style

I prefer this style.

Btw, what is the RAM actually used for ?

I'm not an expert, but basically-
if you want to capture at high speed, or higher speed with more channels, or some combo of that- at some point in there the usb connection can't move data fast enough. So, with buffer mode the capture takes place to the sdram which can handle the bandwidth of the moving data. When your samples are done (whatever number of samples you wanted, up to the limit of the sdram), it gets transferred to the PC. With the lower memory of the Basic, you just can't fit much in 16K (or whatever it is). With 256Mbit, you have a lot more storage space so you can capture more samples at the high rate you wanted. It also looks like if you want advanced triggers, you have to use the buffer.

It looks to me like streaming can handle most needs, but if not, you have the option to buffer. Which is why I think this LA is nice, you have both options.

This does not appear to work for me on Windows 10

I have Windows 10 on several PC's, I just tried- worked just like my Linux PC. Did you unplug the device after changing the 2 files?

I would also like to change the colors of DSView to match my KDE theme-
https://photos.app.goo.gl/GPkL10x10kqoqygN2
(DSView is kinda brownish)
I'm sure it can be done, just need to figure out what to change in the QT style files. Maybe it would be better to have the option to read the style from a file if available.

[Frddy]

I prefer this style.

Yeah but, weren't they 'coax style' mostly to prevent large inductive loops. I was a bit dissapointed when I found out.. Ah well, maybe it's not too bad.

I'm not an expert, but basically-
if you want to capture at high speed, or higher speed with more channels, or some combo of that- at some point in there the usb connection can't move data fast enough. So, with buffer mode the capture takes place to the sdram which can handle the bandwidth of the moving data. When your samples are done (whatever number of samples you wanted, up to the limit of the sdram), it gets transferred to the PC. With the lower memory of the Basic, you just can't fit much in 16K (or whatever it is). With 256Mbit, you have a lot more storage space so you can capture more samples at the high rate you wanted. It also looks like if you want advanced triggers, you have to use the buffer.

It looks to me like streaming can handle most needs, but if not, you have the option to buffer. Which is why I think this LA is nice, you have both options.

So I tried to use buffer mode a little bit, and as far as I've seen it still works well on my model.. Maybe it uses RLE and my test was too easy to compress.. Probably.. :p I was just wondering when exactly it's used. I would think always for the entire buffer, in buffer mode.. But 'buffer mode' was working for me just now..

I have Windows 10 on several PC's, I just tried- worked just like my Linux PC. Did you unplug the device after changing the 2 files?

Of course Maybe I'm too tired, will try again later.. Will also check if it works on my Mac.. Though I'm finding that the GUI doesn't really run smoothly on OSX.

[abraxa]

I prefer this style.

Yeah but, weren't they 'coax style' mostly to prevent large inductive loops. I was a bit dissapointed when I found out.. Ah well, maybe it's not too bad.

From what I remember, the DSLogic had pretty bad signal integrity, partly due to the way their input cable harness was designed. I remember tests by a sigrok team member where the ringing caused additional signal edges, so yes, I would want the coax cables if I had a choice. As for you, I'd say it depends on the signals you commonly look at. Just keep in mind that when the signals look off, it may be because of this issue.

[cv007]

I was just wondering when exactly it's used

Sorry I over-simplified, and responded with info you already knew. I understand your question now, and it is the same one I have. It seems just from playing around, the time will come when one wants to use the advanced trigger to capture a specific event that only the advanced trigger can handle (advanced trigger requires buffer mode). Along with capturing a specific event, it may be required to also see a time frame that is too large for the smaller buffer. With typical lower speed stuff, the advanced trigger may come into play long before the need for a the high sampling rate. That's my guess.

I would also like to change the colors of DSView to match my KDE theme-

It looks like QT apps can take a -stylesheet command line argument, and although it does accept the argument and seems to be happy, no changes show up. I think the setting of the stylesheet in the app (compiled into app as resource) happens after that, so will not work. There are also hard coded colors in some places, which the stylesheet will not apply to.

I grepped the files for the background color QColor(48, 47, 47, 255), and #302F2F, and replaced them with my new color (only 4 files needed changing). I recompiled.  It worked, but there are a few things that were darker versions of the background that I missed.  My previous post has a link to screenshots. I would probably like to change the signal area to a darker color to match something like the Dolphin file manager screenshot I have (instead of one background color everywhere).

I'm sure a simple change to the application startup where the stylesheet is loaded would work (check for external stylesheet, if none, load from internal resource). I'm not sure about the other hard coded colors, though- maybe could be added to the stylesheet somehow (I know very little about QT).


edit-
I just added a simple check in main.cpp where it loads the internal stylesheet, to simply check if one is already loaded (via command line). So now, I can pass a command line argument to DSView and change colors as needed via a style.qss file and icons.  I found a breeze qt stylesheet on gituhub, and used as my starting point. After some mods, I'm close to the KDE breeze theme. I still have a pixel overlap in the main trace area with the border, but its probably as close as I can get it (its the last picture in my screenshots link).

[cv007]

DSLogicBasic-

Soldered on a MT48LC16M16A2TG-6A:GTR ($2.33), copied the Plus fw/bin files to the Basic fw/bin files- works ok (no need to change pid).
https://photos.app.goo.gl/GPkL10x10kqoqygN2 (last picture shows screenshot with the Plus 'upgrade')

I'm not sure why, but I can't get the 200MHz/400MHz options to work, which I will never use (cannot select the channels 0-7/200MHz or channels 0-3/400MHz options).

So basically I now have usable 25/50/100MHz capture options. My expectations were not high, but I am liking this DSLogic device and has good bang for the buck (<$75 total).

[trevwhite]

Sorry if this is a dumb question. Does streaming mode continuously capture and decode or do you have to sample a certain size of data and then decode after?

Thanks

Trev

[cv007]

Its always a two step process- capture, display/decode.

1. Capture at specified sample rate for specified number of samples (while capturing- nothing displayed). The capture can be streaming directly to the PC, or can capture to internal device ram, then transfer to PC- either way is the same as far as the capture step is concerned.
2. Display (and optionally decode) captured data.

There is a 'Repetitive' mode, which captures/displays/repeat every n seconds, but the minimum rate is 1 second.

So, unlike a scope with a real time serial decoder for example, you cannot see real time events. Instead, you specify a trigger condition, or just grab a bunch of samples, and then look it over (and decode). I'm not sure if the real time decoding (of a scope) is a major advantage as you will want a record of it in any case (although a scope can also show analogue signals, which may be useful to see along with real time decoded protocol). The logic analyzer advantage is you are not limited to decoding the relatively few protocols that may be in the scope, and since you are capturing to a PC I imagine its much easier to deal with than trying to fiddle around with knobs/buttons/menus on a 7" display looking at a 30 second capture.

[bson]

24MHz is very slow and can't provide timing precision past 1/24M = ~40ns.  This makes it useless for anything but the most elementary tasks, mainly limiting it to sniffing low speed buses in already working products.  For things even like looking at external SRAM bus timing and why it fails past some remarkably low clock - practically useless.  All it can tell you is that it fails, maybe, if you happen to split two racing edges, but you probably knew that already before even attaching a probe...  Even for HC logic with its modest transition times, at a sluggish 10MHz you really want at least a 100MHz sampling rate.  Most modern uC's and logic interfaces operate closer to LVC though, so forget debugging with a 24MHz sampling rate; for these even a 500MHz time base is quite limiting.  Of course, if it were sophisticated enough to run a 1 or 4GHz timer and timestamp events at up to 24MHz that would be a different matter altogether, so the key here is the slow time base, not the sampling rate per se.

I'd never buy one of these clones.  What if someone sold your products for manufacturing cost, that you spent $10M on for R&D, labeling it with your trademarked product name and pretending to be you?  This would put you out of business quickly, because they don't have anything to recoup, and they're not spending another $10M on your next product - they will just clone that, too.  What if I were to clone and sell Dave's uCurrent for $2, indistinguishable from the original, effectively bringing his sales to approximately $0?  Do you think that's okay?  If so, you really need to recalibrate your moral compass.

Why aren't they making their own equally simply but independently designed product?  I'll tell you why: because that would require hiring an engineer or two, and engineers cost money; they need instruments and facilities, and even though any half decent engineer can crank out a design for this since it's such a simple problem - it's still work, will take time (and hence cost payroll), require an initial capital investment in facilities and equipment, budgeting and hence engineering management, prototype runs, debugging, physical fitting and case design - and then software support even if it consists only of a trivial Windows driver based on an MSDN template, and adding support to Sigrok.  (Unless you can find someone to volunteer to do it for free for your commercial product that nobody has even seen yet.)  The reason they don't do it is because all of these activities cost money, and the moment they actually have to start spending on product R&D it becomes impossible to sell their product for $6.

[cv007]

I'm not sure why, but I can't get the 200MHz/400MHz options to work

It took a while to figure out as I always end up going in circles looking at the source code.
The code to check the channel group is using the radio button text to determine which button was pressed, which then gets compared back to the array of text the radiobutton text originated from, and then gets its index into the array via a string compare. It turns out somewhere in the black hole of QT, an ampersand is added to the radiobutton text which causes any string compare to fail, so no match and no ability to change the option. The ampersand is for a shortcut key, but I'm not sure why QT is adding one when the text used to create the radio buttons have no ampersands. In any case, removing any '&' found in the string before the string compare fixes the problem.

[phil from seattle]

[Nausea]Could be that the & is for windows - it's used to denote the "accelerator" key for keyboard use of the menu system.[\Nausea]  It should be stripped for compares.

[cv007]

but I'm not sure why QT is adding one when the text used to create the radio buttons have no ampersands

It appears KDE is injecting the ampersand into QT apps. How very thoughtful of them  
(I'm sure they are trying to be helpful to the 'careless' -in their minds- QT app authors who don't have shortcut keys to every button/widget/menu, but they leave a trail of broken apps when they do these things)

[DC1MC]

Hello all, found this topic while being desperate that I've lost an Intronix LogicPort 36 channels on fleabay 

Can someone recommend a LA with similar features, available on short notice in Germany (that is before everything shuts down for xmas/ny) on a budget no higher than 250EUR ? If I can't find anything I have to cancel a very nice project and I'll hate it.

Or if somebody can loan one to me, please PM

DC1MC

[hli]

I can recommend the Digilent Digital Discovery (up to 800Msps, up to 32 channels, but not both). Nice software, with extensive triggering capabilities. But I doubt that you will get it fast enough for christmas.

[alm]

Hello all, found this topic while being desperate that I've lost an Intronix LogicPort 36 channels on fleabay 

Can someone recommend a LA with similar features, available on short notice in Germany (that is before everything shuts down for xmas/ny) on a budget no higher than 250EUR ? If I can't find anything I have to cancel a very nice project and I'll hate it.

It's hard to give an intelligent answer to this without knowing more than "similar features to the LogicPort". If it is about channel count, there may be some old HP logic analyzers (which are slightly bigger ) available with 32+ channels locally for < $250, like the 1670 series mentioned in this thread. Some will have much deeper memory and more advanced triggering. If you don't need as many channels but want serial protocol decoding, there are options like the DSLogic or possibly a used Saleae 16-channel model.

[DC1MC]

Hello all, found this topic while being desperate that I've lost an Intronix LogicPort 36 channels on fleabay 

Can someone recommend a LA with similar features, available on short notice in Germany (that is before everything shuts down for xmas/ny) on a budget no higher than 250EUR ? If I can't find anything I have to cancel a very nice project and I'll hate it.

It's hard to give an intelligent answer to this without knowing more than "similar features to the LogicPort". If it is about channel count, there may be some old HP logic analyzers (which are slightly bigger ) available with 32+ channels locally for < $250, like the 1670 series mentioned in this thread. Some will have much deeper memory and more advanced triggering. If you don't need as many channels but want serial protocol decoding, there are options like the DSLogic or possibly a used Saleae 16-channel model.

What intelligent answers are, there is nothing comparable in this price range, they either have a miserable to nonexistent AFE,  an advertised speed that's valid only on 1/8 of the channels in sunny, but not very humid days and only with this "special" high speed adapter (looking at you Digilent) because our AFE is crap, and so on, the person that got my Intronix on fleabay, knew what was doing, I was naive.

True about the old HPs and even there is this Phillips beauty available:

https://www.ebay-kleinanzeigen.de/s-anzeige/philips-logic-analyser-logikanalysator-pm3585-61-200mhz/775106390-168-7267

Unfortunately, I need lots of fast channels, the device should not break the desk and/or the floor under it ,and if possible, should not have noisy ventilators (I have a small apartment and and my better half becomes grumpy when my R&S generator, the TDS840 and the transceiver are all running together, not to mention that stresses my cat) and not emit CRT X-Ray, I've stayed over 35yrs with my face in this stuff and so far I've cheated cancer, I don't want to push it.

OK then, because we have here such an inquisitive gang and engineers like to solve problems, also not forgetting the questions: "but what are you trying to with it that can't be done with an 8 ch/2MHz Cypress, eh, eh ?!?!, I can decode everything with a Salae and Arduino and some Python scripts, even the cryptic and complex 7-segment display protocol, what could you have that can't be done already with them, this it's not possible, it doesn't exist, so, eh, eh ??", so here we go:

- I fully don't need or care of any I2C, SPI, CAN bus, sync or async serial buses, for this my scope does an excellent job.
- I have to decode the protocol on some high-speed proprietary buses between some modules of a device, the bus it's strangely 19bits (?) plus clock and some control signals.
- I need to capture a bit stream load in a most strange mixture of parallel-serial single ended bus that I've ever had the unhappiness to see.
- I want to decode an LCD panel drive sequence, here a good AFE with variable and under zero logic level is mandatory.
- I need to read some external storage device that holds some important irreplaceable calibration data and other constants and it has a lot of pins.
- In the end, I wanted to make nice Christmas/New Year present to the community here (and me as well) by decoding, documenting and opening the specifications of the FY6600. This project it's now 98.5% canceled, barring some X-mas wonder like: "I live in a neighbor city/village, I have an Intronix for sale, come and get it...".
Well, THIS task could be indeed done with whatever arduino, Salae or other sinoschrott available, because I doubt logic stuff there on the FP to signal board gets over 10KHz clock, but if I do unpaid work, I want to do it in a way that pleases me, "not whatever does the job", I'm not the one to hit the screw with a hammer because I don't have a screwdriver at hand and I must do it NOW.

 So if you still have suggestions, knowing what I want to do with the Intronix, please say them, I will at least use them to convince some Intronix owners that they don't need it.


 Cheers,
 DC1MC

[0xdeadbeef]

If you're looking for an Intronix LogicPort in Germany, it would have been more promising to ask in the "mikrocontroller" forum.

Anyway, fully configurable trigger thresholds, specifically negative ones, are nothing to be found in most "cheap" Logic Analyzer.
The Acute TravelLogic LAs seems to have this (in addition to complex triggers and deep memory) but they are a bit outside your expected price range.

However there are devices like the Hantek  LA5034 that sound suspiciously like the Intronix (including the very limited memory).
The LA5034 is even available at Amazon.

There were also obvious Intronix clones available on Amazon/eBay/BangGood which were advertised to be compatible to the Intronix software (i.e. search for "500mhz fpga logic analyzer").
I guess though the Hantek thing is somewhat more legit and uses its own software. Which however could be a bad thing.
It was discussed here once but there wasn't much useful information in this thread and the pictures are gone now.

[lfsing]

DSLogicBasic-

Soldered on a MT48LC16M16A2TG-6A:GTR ($2.33)

Upgrade DslogicBasic to DslogicPlus !!!!!

I did the above  thing, plus reprogramming the SEEP 24LC128 .
Take out the SEEP , Read and its data to file. edit this files , search for exists of data "0E2A2100".
Modify this data to "0E2A2000". and save file.   Write this data file to SEEP.
It works................Most importantly, no need to fool around with the firmware files..

 

[Carrington]

What do you think about this one?
https://www.thelabeshop.com/Analyzers/Protocol-Analyzers/Multi-Protocol/Acute-TravelBus-TB1016E/

It has HW triggers for: DALI, HID over I2C, I2C, I2S, LIN, MDIO, PMBus, RS232, SMBus, SPI, USB1.1.
And it can decode a ton of protocols, and capture at 200Msps (real-time) directly to PC memory (USB 3.0).
With to modes: Protocol Analyzer Mode and Logic Analyzer.

[lfldp]

hello
i found wrong informations in this topic , have also one question

this informations are correct:

pro version:

up to 100mhz acceptable bandwitch 256mbit memory and up to 400ms/s buffer

old version (first one which i already have):

up to 50mhz acceptable bandwitch 64mbit memory and up to 200ms/s buffer

so  previous infromations are incorrect

i have problem with dslogic oldest version (the problem with original cables noises) im getting junk while i tryin sniff spi communication , does maybe exist another (better) cables to buy for use with it ?

thanks

[mindcrime]

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz.

Scott

Heh. This is where I'm at as well. Mostly interested in retro-computing projects using 8-bit processors like the Z80, etc.  In the end, I decided to buy a 136 channel HP 1660A logic analyzer.  It's way overkill for what I'm doing, but, well.. TEA syndrome and all that.  I also have a Zeroplus LAP-C 16-channel USB device, and a Sparkfun Bus Pirate, so I figure I'm covered one way or another.

The Zeroplus works with Sigrok, which is the main reason I went with that. (I'm something of an ideologue for F/OSS).

Anyway, I'll just say, be wary of Ebay... TEA is no joke.      I already don't know where the heck I'm going to put this 1660A when it comes in.  I'll probably have to throw my TV out to make room for it...

[TheNewLab]

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz.

Scott

Heh. This is where I'm at as well. Mostly interested in retro-computing projects using 8-bit processors like the Z80, etc.  In the end, I decided to buy a 136 channel HP 1660A logic analyzer.  It's way overkill for what I'm doing, but, well.. TEA syndrome and all that.  I also have a Zeroplus LAP-C 16-channel USB device, and a Sparkfun Bus Pirate, so I figure I'm covered one way or another.

The Zeroplus works with Sigrok, which is the main reason I went with that. (I'm something of an ideologue for F/OSS).

Anyway, I'll just say, be wary of Ebay... TEA is no joke.      I already don't know where the heck I'm going to put this 1660A when it comes in.  I'll probably have to throw my TV out to make room for it...

LOL, aside from consuming space, it gets expensive doesn't it.  LOL

[AngusBeef]

Young guy here just getting into electronics. Got a DSLogic Basic and now I'm looking to see if I can upgrade it.

I noticed that only the SRAM is missing when comparing my chip to the photos of PCBs on Sigrok's website. Then I found this thread - so it seems it's a simple as soldering on the SRAM and renaming the firmware files so it downloads a different firmware into the EEPROM...?

I picked up a MT48LC16M16A2P-6A:G SRAM chip (https://www.mouser.com/ProductDetail/340-128308-TRAY) which is different than the one mentioned in this thread (-GT:R I think), but mirrors the chip from the DSLogic Plus hardware photos on SigRok's site.

Also, one gentleman mentioned removing a SEEP and altering a memory address and I don't quite understand what that means. I assume it's the EEPROM?

[pigrew]

Young guy here just getting into electronics. Got a DSLogic Basic and now I'm looking to see if I can upgrade it.

I noticed that only the SRAM is missing when comparing my chip to the photos of PCBs on Sigrok's website. Then I found this thread - so it seems it's a simple as soldering on the SRAM and renaming the firmware files so it downloads a different firmware into the EEPROM...?

I picked up a MT48LC16M16A2P-6A:G SRAM chip (https://www.mouser.com/ProductDetail/340-128308-TRAY) which is different than the one mentioned in this thread (-GT:R I think), but mirrors the chip from the DSLogic Plus hardware photos on SigRok's site.

Also, one gentleman mentioned removing a SEEP and altering a memory address and I don't quite understand what that means. I assume it's the EEPROM?

Yes, I think that's what it must be. I found https://weekly-geekly.github.io/articles/445024/index.html which has photo instructions.... That post links back to this thread... weird.

I ordered a "plus" about a week ago, which I'm excepting to arrive soon. It's possible that the company will implement serial number checks in future firmware releases or something to disable an "upgraded" unit.... we'll see.

I had a misconception about its adjustable thershold. I figured the plus model would use comparators on its inputs, but it doesn't. It just uses the internal threshold voltage of the FPGA as a threshold reference, probably with a PWM DAC from the FPGA to control it. I'm also curious about the input series resistors on the board, as if they are high enough they will seriously reduce the bandwidth since they don't have parallel capacitors. I wonder if its response could be improved by putting some ~47 pF (wild guess) caps on top of the resistors on each input channel (the column of resistors right at the FPGA). Also, is the FPGA using 3.3V or 1.8 V logic levels on the input? Probably the 1.8 would give a more reproducible threshold.

So, I've never used the DSLogic before, but it does seem like it's a not too difficult thing to do.

Another complaint is that the probe leads are too long! They should be shorter to minimize the distance of their compensation network to the probe. I'd be curious about measuring their input impedance. However, adding an additional board in the middle of the probe would add cost, and maybe not increase the performance by much.

[AngusBeef]

Yes, I think that's what it must be. I found https://weekly-geekly.github.io/articles/445024/index.html which has photo instructions.... That post links back to this thread... weird.

I ordered a "plus" about a week ago, which I'm excepting to arrive soon. It's possible that the company will implement serial number checks in future firmware releases or something to disable an "upgraded" unit.... we'll see.

I had a misconception about its adjustable thershold. I figured the plus model would use comparators on its inputs, but it doesn't. It just uses the internal threshold voltage of the FPGA as a threshold reference, probably with a PWM DAC from the FPGA to control it. I'm also curious about the input series resistors on the board, as if they are high enough they will seriously reduce the bandwidth since they don't have parallel capacitors. I wonder if its response could be improved by putting some ~47 pF (wild guess) caps on top of the resistors on each input channel (the column of resistors right at the FPGA). Also, is the FPGA using 3.3V or 1.8 V logic levels on the input? Probably the 1.8 would give a more reproducible threshold.

So, I've never used the DSLogic before, but it does seem like it's a not too difficult thing to do.

Another complaint is that the probe leads are too long! They should be shorter to minimize the distance of their compensation network to the probe. I'd be curious about measuring their input impedance. However, adding an additional board in the middle of the probe would add cost, and maybe not increase the performance by much.

I've watched one of the videos above and it appears that the way they designed the input leads and the input series resistors leads to ringing in circuits and places a significant load on the DUT. But they recommend it anyway so it may not be enough to trigger the threshold values?

Also, I think serial number checks are unlikely - DSLogic is mostly defunct now from everything I've heard. Even their website still says 2018 at the bottom. And there are so many clones.

DSLogicBasic-

Soldered on a MT48LC16M16A2TG-6A:GTR ($2.33)

Upgrade DslogicBasic to DslogicPlus !!!!!

I did the above  thing, plus reprogramming the SEEP 24LC128 .
Take out the SEEP , Read and its data to file. edit this files , search for exists of data "0E2A2100".
Modify this data to "0E2A2000". and save file.   Write this data file to SEEP.
It works................Most importantly, no need to fool around with the firmware files..

I would guess this gentleman is the one who wrote the article you linked. I have no idea how to program EEPROM since I've really only been learning electronics for a month so it'll be an adventure. I would think it's possible to flash it through the USB interface, but I have no idea how to do that either. Yet!

[pigrew]

I've watched one of the videos above and it appears that the way they designed the input leads and the input series resistors leads to ringing in circuits and places a significant load on the DUT. But they recommend it anyway so it may not be enough to trigger the threshold values?

Also, I think serial number checks are unlikely - DSLogic is mostly defunct now from everything I've heard. Even their website still says 2018 at the bottom. And there are so many clones.

I would guess this gentleman is the one who wrote the article you linked. I have no idea how to program EEPROM since I've really only been learning electronics for a month so it'll be an adventure. I would think it's possible to flash it through the USB interface, but I have no idea how to do that either. Yet!

I think that the bandwidth is probably good enough, up to a point.... My guess is 50 or 100 MHz bandwidth, not sure. I don't even know how I would define the bandwidth of the LA.... I hope the bandwidth is at least close to the sample rate, but I doubt that it is.

It looks like just swapping the firmware filenames or editing the profile list would be the easiest option. I think that it's serial flash, so you could write to it from a mcu, or buy a special programmer to write to it. But, it's easiest to just try swapping the files on the computer.

I don't think that DSLogic is quite dead. They just released a new version of their DSView software. looking at it, it has a lot of room for improvement, but it's usable. There are a huge number of branches on GitHub, but few if any ever get merged back into the trunk. I don't think that there are any clones, I think that they're just selling through the "normal" online Chinese distribution networks where everyone sells it on TaoBao without any sellers knowing any details about it......

The length matching of the tracks on the PCB is beautiful. I'm curious about how well it works with its "use external clock" mode. Do they trigger the IO cell registers on the external clock, or do they fake it by just analyzing the data they sampled at 400 MHz? How much skew is there?

[pgo]

You should look at this thread for how to program over USB without requiring a programmer.
Requires soldering a link however.

https://www.eevblog.com/forum/testgear/upgrading-dslogic-basic-to-plus-without-eeprom-modification/msg2594313/#msg2594313

[AngusBeef]

You should look at this thread for how to program over USB without requiring a programmer.
Requires soldering a link however.

https://www.eevblog.com/forum/testgear/upgrading-dslogic-basic-to-plus-without-eeprom-modification/msg2594313/#msg2594313

You don't have to solder the link, just connect pins 4 and 7 with two EZ-Hook style probes.

You do have to solder the RAM chip, but it's simple drag soldering.

[Crazy_Fox]

The length matching of the tracks on the PCB is beautiful.

Could you explain, please, how do you measured the length of tracks, or just say what the length is ?
I got U2Basic version, and on the PCB they removed track from FPGA to A12 pin of DRAM, so seems I need to add the wire link with the same length as tracks to be able to use 256Mb.

[pgo]

Hi Crazy_Fox,

I'm surprised they have done this.  I checked on the one I have and it has a connection to A12.  I suggest you check this yourself if you have not done so.

You can try measuring the traces on a photograph and a high zoom and then scale appropriately.
Suitable photos are available on this thread: https://www.eevblog.com/forum/testgear/usb-logic-analyzers/msg1333915/#msg1333915

Note that the track is below the IC and then on the rear of the board with two vias.

bye

 

[liyang]

I got U2Basic version, and on the PCB they removed track from FPGA to A12 pin of DRAM, so seems I need to add the wire link with the same length as tracks to be able to use 256Mb.

I'm surprised they have done this.  I checked on the one I have and it has a connection to A12.  I suggest you check this yourself if you have not done so.
…
Note that the track is below the IC and then on the rear of the board with two vias.

Hi Crazy_Fox & pgo,

I just got my U2Basic (unfortunately) from Banggood, and it looks like I don't have A12 connected either. (There's no via on mine compared to the photo pgo mentioned.)

@Crazy_Fox: my board is labelled DSLogic-U2B-V111-P0808; what's yours?

[jake111]

I'd like to get a logic analyzer for use with some retrocomputing projects that use a bus speed of 4 - 16 Mhz. Checking ebay, I can find the following:

* Salae 8-channel 24 Mhz for around $6
* Salae 16-channel 100 MHz for around $43
* SeeedStudio 16-channel 100 MHz / 4-channel 400 Mhz for around $75

I'm thinking the 16-channel 100 Mhz products fit my use case with room to expand. The 8-channel 24 Mhz is appealing solely because at $6 if I do something stupid and ruin it, I can throw it away and not feel bad.

Any experiences with these products? is the software decent?

Scott

I have used a great many logic analyzers over the years in troubleshooting digital bus issues the origin of which were in the analog domain.  I absolutely love the Saleae but I have the pro series that lets you stream through USB 3.0 and this is a huge benefit.  Saleae's software is really great.  If you are always able to set up creative triggers for what you are working on, then you can make the cheaper ones useful, but I have used quite a few of these chinese logic analyzers that are really just copies of copies of copies and as you would expect, they are all kind of junk in one way or another.  I like products that are designed to function well for their purpose, not products which are just copies of other designs optimized to be as cheap as possible and assembled or packaged with child labor.