USB Logic Analyzer Recommendation

[pascal_sweden]

You could use the Cypress EZ-USB FX2LP evaluation board as a cheap logic analyzer.

https://www.aliexpress.com/item/1907809277.html

https://community.cypress.com/docs/DOC-18867

https://www.cypress.com/products/ez-usb-fx2lp

[Gandalf_Sr]

I didn't watch the whole thing but that's quite a good video.  Thanks

[Roicker]

This video is actually a great starting point for anyone looking to get a logic analyzer, just because it explains the limitation of physical sensing of the signal

[Tarloth]

Hi!

As I did post in another question, I use for my work the Open Bench Logic Sniffer and work like a charm, better than salea or others than I try. It's completely open source, very powerful and inexpensive. With some minor modifications you can use Agilent Logic analyzers cables (I buy a bunch of new parts but old stock in ebay for less than a multimeter probe). A friend uses Bus Pirate and told me that it's perfect. Also completely opensource.

http://dangerousprototypes.com/docs/Main_Page

[robca]

Hi!

As I did post in another question, I use for my work the Open Bench Logic Sniffer and work like a charm, better than salea or others than I try. It's completely open source, very powerful and inexpensive. With some minor modifications you can use Agilent Logic analyzers cables (I buy a bunch of new parts but old stock in ebay for less than a multimeter probe). A friend uses Bus Pirate and told me that it's perfect. Also completely opensource.

http://dangerousprototypes.com/docs/Main_Page

Looks interesting, but it doesn't seem to be available for sale anymore, at least in the USA...

[0xdeadbeef]

Come on, the logic sniffer was nice about ten years ago, but it never lived up to its expectations regarding complex triggers and now it's just completely and utterly outdated. At this point, the classic DSLogic Plus is still the best bang for the buck since the USB3 version is still much too expensive.

[Tarloth]

Come on, the logic sniffer was nice about ten years ago, but it never lived up to its expectations regarding complex triggers and now it's just completely and utterly outdated. At this point, the classic DSLogic Plus is still the best bang for the buck since the USB3 version is still much too expensive.

Why outdated? Yes with the original software you can't use serial triggers but it's not a problem for most people that considere cheap logic analyzers of ebay aceptables. Yo can use it with Sigrok and pulse view and decode a lot of protocols (https://sigrok.org/wiki/Protocol_decoders).

OBLS has 32 channel and 100 Mhz or 16 channels at 200Mhz! Most of the cheap logic analyzer recommended in this post has 8 channels in 24Mhz (at best) and uses the same software! DSLogic Plus in 16 channels has only 20Mhz (in stream mode, to compare with OBLS) and cost more than 100 dollars!

If you not like anything you can add the functionality. SUMP was a nice project and really have all that most of user needs from a LA. The VHDL runs almost in any FPGA 90% of the FPGA "demo boards" can be converted in a logic analyzer . Some students port this VHDL to 500Mhz FPGA without problems and a friend eliminates the PIC chip and replaces it with an ARM WIFI module and is working with a direct HTML port to a PC or tablet remote and isolate!

Not like the SUMP or need some more modern, you can buy a demo FPGA board and install SUMP2! https://blackmesalabs.wordpress.com/2016/10/24/sump2-96-msps-logic-analyzer-for-22/

For comparing again with DSLogiq Plus this board it's five time faster, better decoding and cost half or less. Do you like an standalone instrument, use the RPI version with monitor! https://blackmesalabs.wordpress.com/2016/12/22/sump2-100-msps-32bit-logic-analyzer-for-icoboardraspberrypi/

Which task can't do with these SUMP based LA?

[0xdeadbeef]

Why outdated?

Because it's a old design with a really small memory (like 24k samples or so).
And shops that sold it ten years ago don't sell it anymore. Is it even still produced and/or sold somewhere?

[Tarloth]

But OBLS descendant are alive and with better characteristics than DSProbe Plus (for example) at a fraction of the cost. I used a lot of logic analyzers since the 80's, even big brands standalone devices, and for the cost, the one's based on SUMP concept are far better than others.

[robca]

But OBLS descendant are alive and with better characteristics than DSProbe Plus (for example) at a fraction of the cost. I used a lot of logic analyzers since the 80's, even big brands standalone devices, and for the cost, the one's based on SUMP concept are far better than others.

Is there a product anyone can buy? Or is this an option only for someone willing to mess around with a FPGA board, design the input stage for various logic voltages, etc?

[Fungus]

There's also the Digital Discovery.

I always thought the DD was just the Analog Discovery without the analog part but noooooo, I found out last week it has 800Mhz sample rate.

The DD software also has real time data view and just about every decoder under the sun (and if it doesn't have it, you can add your own).

[0xdeadbeef]

But OBLS descendant are alive and with better characteristics than DSProbe Plus (for example) at a fraction of the cost. I used a lot of logic analyzers since the 80's, even big brands standalone devices, and for the cost, the one's based on SUMP concept are far better than others.

Letting aside issues with the GUI, or if they are commercially available in a proper case etc.: does any of these approaches have a proper input protection or a configurable logic threshold or shielded probes?
The DSLogic Plus has all of this and just works pretty well in most everyday scenario. I'd still say that you can't really expect much more for the price.
I also like(d) the Ikalogic products, but the ScanaPlus is no longer available and the SP209 is a bit too expensive for what it is. Also the software development was a bit of two steps forward, one step back in the last ten years or so. I still like the GUI though and the Ikalogic devices have/had about the most advanced trigger options in their price range.

[Bassman59]

If you not like anything you can add the functionality. SUMP was a nice project and really have all that most of user needs from a LA. The VHDL runs almost in any FPGA 90% of the FPGA "demo boards" can be converted in a logic analyzer . Some students port this VHDL to 500Mhz FPGA without problems and a friend eliminates the PIC chip and replaces it with an ARM WIFI module and is working with a direct HTML port to a PC or tablet remote and isolate!

Not like the SUMP or need some more modern, you can buy a demo FPGA board and install SUMP2! https://blackmesalabs.wordpress.com/2016/10/24/sump2-96-msps-logic-analyzer-for-22/

Seriously -- a logic analyzer is a great project for seniors in an EE program. It's a very straightforward problem.

The most difficult part of the problem is the host software/GUI! And SUMP2 looks like it fits the bill.

[robca]

If you not like anything you can add the functionality. SUMP was a nice project and really have all that most of user needs from a LA. The VHDL runs almost in any FPGA 90% of the FPGA "demo boards" can be converted in a logic analyzer . Some students port this VHDL to 500Mhz FPGA without problems and a friend eliminates the PIC chip and replaces it with an ARM WIFI module and is working with a direct HTML port to a PC or tablet remote and isolate!

Not like the SUMP or need some more modern, you can buy a demo FPGA board and install SUMP2! https://blackmesalabs.wordpress.com/2016/10/24/sump2-96-msps-logic-analyzer-for-22/

Seriously -- a logic analyzer is a great project for seniors in an EE program. It's a very straightforward problem.

The most difficult part of the problem is the host software/GUI! And SUMP2 looks like it fits the bill.

Sure, but... a Dslogic Basic costs $55 currently on AliExpress with shielded leads https://www.aliexpress.com/item/4000154727610.html (just placed an order, not sure if what I receive is what's pictured there, so caveat emptor... but there are plenty that cost around $60). Can be updated to Logic Plus with just a SRAM IC and minimal work, but even the basic version is pretty functional.

Putting together a SUMP2 plus designing the input front end, buying the leads... Can't be done for less. It might have more functionality in the end, but for a higher cost. Also, the SUMP2 software seems to have been frozen ~2 years ago and there doesn't seem to be much interest in SUMP2 designs post 2018. Dslogic at least is supported by sigrok, and that's guaranteed to continue in the future, plus the current software is open source as much as SUMP2.

And I can't find protocols beyond I2C and SPI for the SUMP2 (might be my fault, apologies in advance if that's the case), while Dslogic inherits all the sigrok ones

For anyone to design a logic analyzer around the SUMP2 design, it seems a rather bad investment, since there won't be much of a community around it to benefit from it (unless that person also does the heavy lifting of adding SUMP2 designs to sigrok). Might be a great learning project, but hardly worth it as an actual tool

All in all, a SUMP2 design for the low cost market seem not to make much sense to me...

[0xdeadbeef]

And I can't find protocols beyond I2C and SPI for the SUMP2 (might be my fault, apologies in advance if that's the case), while Dslogic inherits all the sigrok ones

Plus you can write your own decoders in Python. Must admit I didn't use it yet, but I wrote my own decoders in JavaScript for Ikalogic's ScanaStudio and IMHO such a scripting capability is a major advantage.
Anyway, regarding DSLogic: not only the GUI software is open source but also the FPGA bitstream is:
https://github.com/DreamSourceLab

[robca]

Protocol scripting is a pretty common functionality, e.g. https://sigrok.org/wiki/Protocol_decoder_HOWTO

The difference is that sigrok and dsview already have 128 protocols ready for use, instead of just SPI and I2C.

Once more, it's the difference between a project you can build to gain experience, vs a ready-to-use logic analyzer (that also costs more once you have everything you need)

[Pack34]

It's hard to beat a Saleae. Works a treat and very easy to automate in Python. I was able to quickly put together a test bed to turn the system on, log configuration of sensors, examine output, and then repeat. Really really useful when knocking loose those 1-in-1000 faults.

https://www.saleae.com/?utm_medium=cpc&utm_source=bing&utm_campaign=search|us&utm_term=34552757958&utm_content=5231159148

[Tarloth]

Letting aside issues with the GUI, or if they are commercially available in a proper case etc.: does any of these approaches have a proper input protection or a configurable logic threshold or shielded probes?
The DSLogic Plus has all of this and just works pretty well in most everyday scenario.

No, DSlogic Plus HASN'T proper input protection and the configurable logic threshold it's only at FPGA level. It has a R divider (RC adapter inside the new probes) with ESD clamping diodes, not a "circuit protection with configurable thresholds" like big brands logic analyzers. But in all version of SUMP you can add it in circuit or it's present in board. OLS has a buffer that includes 74LCX16245 that protect a lot more than R network and a diode clamp.

You can analyze the DSlogic Plus hardware. It's too much different that any incarnation of SUMP project?

https://sigrok.org/wiki/DreamSourceLab_DSLogic_Plus

https://hackaday.com/2017/08/24/dslogic-plus-teardown-and-review/

https://www.eevblog.com/forum/crowd-funded-projects/dslogic/

Isn't different than any SUMP version but expensive!

You can use the logic analyzer you want, I just said in previous post that it's perfectly posible to solve 90% of embeded needs with logic analyzer derived from original SUMP project, I not put a gun in anybody head to use a Sump derivative.

Protocol scripting is a pretty common functionality, e.g. https://sigrok.org/wiki/Protocol_decoder_HOWTO

The difference is that sigrok and dsview already have 128 protocols ready for use, instead of just SPI and I2C.

Once more, it's the difference between a project you can build to gain experience, vs a ready-to-use logic analyzer (that also costs more once you have everything you need)

Robca, OBLS it's compatible with Sigrok and it's included in the hardware years before than other logic analyzers
 
https://sigrok.org/wiki/Openbench_Logic_Sniffer'

The projects derived from SUM has many options of software plus Sigrok, some software has less decoders but others features, but if you like Sigrok it's 100% compatible. Indeed, I use it.

By the way, OLS was always a final board, not a kit, you did can buy the board plus the enclosure or do a custom enclosure. SUMP2 it's bases in final boards too, you select one that fit your needs.

For example, I love the standalone possibility of the sump2 +rpi. You not need to program anything, you would buy the boards, the screen that you like and download the firmware to a uSD. That's it, you have a Standalone logic Analyzer with screen for less than $150.

Which of the LA that you recommend can work without a computer on your desk? How much is it?

I insist, I only  said that OLS it's perfectly capable of most of analyzer task for less money than other options that, at end, has exactly the same or less characteristics.

I have a friend that says : "The possibility that someone recognizes that some product that he did buys it's crap it's inversely proportional to the cost that he paid"

[2N3055]

I just love when discussion goes this way...

OP wants to buy something simple to work on his Arduino projects.

How is making your own LA and screwing around with open source software to make it work aligning with that agenda... ??
What, he doesn't deserve to to even work on simple Arduino projects until he makes his own LA and makes software for it?

Cmon...

He doesn't want to make an LA. He wants to get one ready made to use it to work on HIS projects...

Saleae works out of the box, but it is too expensive. DSlogic Plus also works out of the box, has good specs and if OP feels like it can be used with Sigrok.

If all of that is too expensive, than some of 10 USD LA clones that work with Sigrok are very cheap and can be made to work without much problem..

Everything else is off topic...

[Gandalf_Sr]

I think 2N3055 is right, we should at least try to give good advice to the OP.  Going back over this thread, it strikes me that there are 2 main groups of users of logic analyzers, basic and advanced which I will define as:

Basic. Examine simple data transfer to/from a device in one of many different protocols. e.g. 'talk' to a SPI device such as a temperature sensor to understand the way it works and maybe work up a simple driver.

Advanced. Study large amounts of data flowing between 2 or more devices on a bus on an existing PCB to understand and maybe debug issues that are suspected as being caused by signal levels, timing, or actual data transfer between the devices.

I tend to work at the basic level and have a need to be able to send as well as receive protocol data and, because of this, I find that I really don't use my real Saleae Logic 8 USB Logic Analyzer (PM me if you want to save me the trouble of listing it on eBay).  I do own the Bus Pirate but, as I said before, it's UI is pretty crude and the firmware is a bit buggy - there is a great overview of the Bus Pirate and how to use it here.  What it will do - that the Saleae Logic 8 USB Logic Analyzer won't - is talk on the SPI/I2C/1Wire bus to discover and test new devices.  It seems to me that this is the level that the OP is working at.

As far as Advanced goes, I really think sophisticated triggering is important so I can find the small amount of data I want to examine in detail rather than having to scroll through megabytes of stuff I don't care about; triggering is an area that the Saleae has been criticized for, don't know whether it's been improved? Having said that, the Saleae interface is very slick and intuitive.

As I look around for something more affordable than the Saleae, the DSLogic Plus with Sigrok looks like great bang for the buck but here's a few questions:

1. What's the difference between the $80ish DSlogic Plus and the $300 DSLogic U3Pro16 on Seeed Studio? The ones I see on eBay when I search for "dslogic plus" are 16 Channel, 50 Meg ones that look identical and have what appears to be the same USB Type C connector as the U3Pro16 that is stated as running in USB 3.0 mode.

2. If I were to buy a DSlogic Plus from eBay for around $80, can anyone recommend a specific seller?

3. Is there any hardware supported by Sigrok that can write as well as read data to the connected bus?

Thanks in advance

[EDIT] There's also a Bus Pirate Console here.

[Pack34]

I just love when discussion goes this way...

OP wants to buy something simple to work on his Arduino projects.

How is making your own LA and screwing around with open source software to make it work aligning with that agenda... ??
What, he doesn't deserve to to even work on simple Arduino projects until he makes his own LA and makes software for it?

Cmon...

He doesn't want to make an LA. He wants to get one ready made to use it to work on HIS projects...

Saleae works out of the box, but it is too expensive. DSlogic Plus also works out of the box, has good specs and if OP feels like it can be used with Sigrok.

If all of that is too expensive, than some of 10 USD LA clones that work with Sigrok are very cheap and can be made to work without much problem..

Everything else is off topic...

The Saleae is a lot cheaper if you're a student or a hobbyist. You can buy the Logic8 from them directly for $199 instead of the full $399. It's still more expensive than the DSLogic but it's $199 vs $149 and not over double the price.
https://blog.saleae.com/saleae-discounts/