Logic Analyzer Opinion

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Hi Freaks...

I'm looking for a Logic Analyser and I would like to hear some users opinion.
My choices:
- LogicPort
- Digiview - DV1-100
- Salea Logic Analyzer

LogicPort the faster one 500MHz sample rate.

Salea Logic A. longest capture time, use RAM computer.

Digiview, signal genaretor, but what I really like is the Asynch. search, it seens to be similar to the PacketPresenter Decoder from USBee, too expensive, (http://www.usbee.com/dxpp.html) does some DV1-100 user's can confirm that?

The LogicPort using compression mode can capture wave forms for long times.

Other thing the Salea Logic A., I don't have the 1.5GHz of CPU, does anyone try on slower than that?

Regards,

Bruno Muswieck

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I have both Saleae and LogicPort.

Using the Saleae on my laptop (CPU AMD Sempron SI-40 2.0GHz) I have hard time sampling at 8MHz for more than few seconds. It may be the CPU, or the fact that there is a bunch of built-in USB devices like webcam reserving bandwidth. The other thing may be Vista which likes to keep 1GB swap file even after reboot, so if I wish to sample stuff and the Saleae software allocates say 500MB, the other 500MB in memory must be swapped to disk.

I have had better success with it on lesser desktop XP pc IIRC. Also 4MHz sampling works fine on laptop too even for longer periods, but sometimes that is just not enough.

But really, these devices cannot be compared as they are for different needs.

Logicport has 1024 or 2048 sample buffer per channel and goes up to 500MHz rate. Even if you use compression mode, it is still 1024 or 2048 samples. It approximately means you can sample a flat line indefinitely, or 1kHz signal for 1 second, or 100kHz signal for 10ms, or 1MHz signal for 1ms, or 10MHz signal for 100us, or 100MHz signal for 10us, before buffer is full and it is transmitted to PC for display and protocol analysis. Fortunately my old 1GHz XP laptop has single USB1 connector so it is enough to run that beast.

And as you know, Saleae analyser dumps whole continuous sampled 8-channel stream to memory and the capture must be stopped before software displays and runs the protocol analysis. Imagine you sample 8 channels for 100Msamples at 8MHz (12.5 seconds), that is 100Mbytes of data. It takes several seconds after capture until it is actually processed for displaying, even more when something like SPI bus decoding is done. I just usually save the raw data and run my own C program to analyze the file.

So basically, I would choose the device based on what and how I am analyzing. I can't analyze or log more than 1024 or 2048 samples per screen with LogicPort, but it can work up to 500MHz rate with 32 channels. Also with 8-channel Saleae and my laptop, I would not try sampling more than 100M samples at 8MHz, and it still fails. It can go longer at 4MHz rate. 16MHz works for shorter samples. 24MHz sampling I can pretty much forget.

Any help?

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I have the LogicPort.
Great piece of equipment, but in these days I need hardly more than 8 channels.
Some Rigol-scopes have a 8line-logic analyzer built in. That may be an option to investigate

Nard

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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Has anyone hacked the Logicport USB communication yet, so it could be used with Linux?

Saleae has promised Linux/Mac support about a year already, shold have been ready last May.

Also, LogicPort supports logic thresholds of -6V..+6V and total DC range of -40 to +40, while Saleae is 5V logic levels only (-0.5V..+5.25V) at TTL compatible inputs (logic 0 <0.8V, logic 1 >2V)

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Thanks guys..

Jeapel and Nard, the LogicPort you can have something like Bus Decoder (http://www.usbee.com/axdec.html) and like PacketPresenter (http://www.usbee.com/dxpp.html).
The packetPresenter let easier to see a data protocol.

Some DigiView User opinion?

Regards,

Bruno Muswieck

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Bruno, Logicport comes with very powerfull software. And there are no hidden costs, like extra fees for different protocols. And what Jani says about the tresholds and input ranges.

The LogicPort is quite expensive IMO, but I don't think I will ever need a better one.

Nard

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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Logicport can decode at least I2C, SPI and UART in software. You can download and try Logicport software before you buy, just like Saleae software, both have some kind of demo modes. I think Saleae software also has 1-Wire as well.

You just need to figure out what features you want and what limitations you can live with.

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Jepael wrote:
I have both Saleae and LogicPort.

Logicport has 1024 or 2048 sample buffer per channel and goes up to 500MHz rate. Even if you use compression mode, it is still 1024 or 2048 samples.

This is not true. The sample buffer is always at least 2048 samples (never 1024) and with compression it is rarely only 2048. I routinely capture 100k or more samples, sometimes many millions in a single buffer acquisition depending upon the data. I think you may be confusing "transitions" with "samples". It is true that it captures between 1023 and 2047 "transitions", but with compression that could be over a capture period of seconds/minutes/hours for a single continuous acquisition. If it samples at 200MHz for 1 second then it captured 200 million "samples" - whether there were 0, 500, or 1000 "transitions" during that 1 second period. With a busy processor bus toggling all displayed channels, there is little compression. With serial protocol analysis where the serial lines often have long dead periods between data bursts, compression is quite substantial.

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As I undertand the problem is when the buffer is filled, the logicport will stop to acquisitate data. But when it's on compression mode, if no transition happen the buffer will get empty and filled again when new transation happens.
And this buffer can handle 2048 samples from the 32 channels.

So this buffer is important to see if LogicPort can handle your needs.

Regards,

Bruno Muswieck

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I have the Digiview DV1-100 , and i have seen no signal generator.

But i like it , so far.

It decodes UART/SPI/I2C , and is easy to use.

I just upgraded to the latest sw , and haven't really gotten into the advanced search yet. Right now i use it for I2C , and it's verry helpfull here.

If i were to buy one today i'd prob. go for a logicport.
But the DV-100 is actually doing ok for me.

I have a "DIY" Saleae , but misses to make an input protection citcuit (prob just a AHCT 245 or the like ,but any hints are welcome).
So i can't talk about that one yet

/Bingo

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brunomusw wrote:
But when it's on compression mode, if no transition happen the buffer will get empty and filled again when new transation happens.
And this buffer can handle 2048 samples from the 32 channels.

No, that's actually sort of the opposite of what happens with compression. If there are no transitions, then the buffer doesn't fill and acquisition doesn't stop. In fact, until there's a trigger event acquisition never stops because the buffer is circular (this is typical of all logic analyzers). So, the important point is what happens after a trigger. If after a trigger event, there are no more transitions, then the buffer still doesn't fill and the acquisition doesn't stop until either you end it early or the specified time limit is reached. This could be hours of continuous sampling compressed into a single buffer full of data. This would be an unusual situation, but I use it to explain the concept.

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Thanks Bingo and mmfiend.

Here is a table between the logic analyser, sugestions are welcome to put more stuffs on the sheet.
If you want I can put the sheet for download.

Attachment(s): 

Regards,

Bruno Muswieck

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I have a Logicport for personal use and I liked it so much that I made my company buy me one for business use. Great device. I've always gotten great support from the manufacturer. I even asked him for CAN decoding support and sure enough, 6 months later, I had CAN decoding support! (I have no idea if it was based on my request, that of others, or what)

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Jepael wrote:
Has anyone hacked the Logicport USB communication yet, so it could be used with Linux?

Wonder if it might work in a virtual machine. I've been using Ubuntu a lot lately, and have found VirtualBox invaluable for running programs like LP Calculator, which are Windows-only.

Michae

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crwper wrote:

Wonder if it might work in a virtual machine. I've been using Ubuntu a lot lately, and have found VirtualBox invaluable for running programs like LP Calculator, which are Windows-only.

I have not tried and I won't install Windows under Linux. If I want a operating system that for whatever reason annoys the life out of me, I rather choose the cheaper alternative than pay for it. I won't run a pirated XP copy, and the paid copies are definitely not suitable for a machine that actually needs to do something experimental, like changing the network cards or hard drives etc too often or it will think it has been transferred to another machine and wants to re-authenticate to the licencing server.

I might try the software under WINE though, but last time I tried to access a USB device under WINE it did not work. Today there is a native Linux program for what I need.

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Another +1 for the LogicPort - I've had mine for over 4 years now and for many debugging projects it is all that I need. THe I2C, SPI, decoders are also very useful and easy to set up.

The only thing you need to be careful of - the USB will connect the ground of the pod through your PC. So, if you are using this on a "live" machine with possible grounding issues, beware that you PC's power supply and/or battery may take a hit if it is tied to earth through the power cord. I let me laptop PC "float" on battery power if I am hooking up to a live machine with questionable grounds or large negative power supply transients.

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Just as a warning , since this is Atmel related forum...

 

DO NOT BUY THE Digiview DV518 !!!

 

That specific analyzer does not work with Atmel studio and any sort of Atmel USB programmers or evaluation boards at the same time.

If you use their their software and the Dv518 you must close Atmel studio.

 

 

I should also add to what i said , that this issue does not happen with MPLAB or lattice diamond. 

 

I can read , write , debug ,etc... all day long with microchip (former Atmel products excluded) and lattice boards and i get no disconnections of the DV518.

 

 

Last Edited: Mon. Jul 9, 2018 - 01:56 PM
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Why? What happens? How does one program interact with the other?

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I dare say there’s an issue with the PID/VIDs clashing.

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When i use the DV518 and digiview without Atmel Studio being up its is all good , no issues at all.

Even if there is an Atmel product (STK 600 , Xplained boards , etc..) connected to the USB it is all good , no issues with the DV518 and Digiview.

 

But as soon as i bring up Atmel Studio and Atmel Studio communicates with any of the Atmel boards , after approximately 4 or 5 communications (programming , checking board settings , reading fuses ,etc...) the DV518 is knocked off. and the capture buttons in Digiview are greyed out.

 

 

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Unfortunately i dont have enough knowledge about USB to figure that out. When im home i can look and see if the VID/PID of the DV518 somehow is the same as any of the Atmel products i own.

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here are the VID/PID of the samd10 xplained mini ..

 

USB\VID_03EB&PID_2145&REV_1000
USB\VID_03EB&PID_2145

 

 

here are the VID/PID of the DV518

 

USB\VID_088A&PID_1009&REV_0000&MI_00
USB\VID_088A&PID_1009&MI_00

 

 

 

 

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So finally i got a replacement DV518.  Turns out that the one i had , had issues with had a defective USB chip.

 

Now everything works as intended and i can enjoy the logic analyzer and can even recommend it now.

 

The tech support of techtools told me that the way atmel studio establishes a connection to their boards is somewhat the sledge hammer style ,  which seems to be true , because other software/hardware combos like mplabx+pic kit  or lattice diamond and lattice FPGA boards did not cause issues with the defective DV518 i used to have.

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Buy an $8 Saleae clone on eBay and download either the Saleae application software or its open-source equivalent.   Work with it creatively.  It will most likely fit your needs.  If it is taking too long to analyze the arrived data, then use a smaller PC-RAM buffer.

 

If this meets your needs, fine.  If not, then give it away to someone who is just beginning to learn embedded system programming and get a more traditional logic analyzer.

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I like the LeCroy LogicStudio. A little more expensive than the others mentioned here, but a much more professional instrument.

 

http://teledynelecroy.com/logics...

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I have been holding back here, but this 9 year old thread keeps getting bumped lately and I can no longer resist.

Simonetta came close to mentioning Sigrok / Pulseview.

https://sigrok.org/

 

Sigrok  (cli interface) and Pulseview (GUI)  is Open Source logic analyser software.

It is compaible with a lot of LA hardware.

For beginners I recommend the "24MHz 8ch" boards from Ali / Ebay / China, and these are same "clones" that Simonetta mentioned.

The hardware in those boxes is just a Cypress CY7C68013A microcontroller and some protection resistors and other chicken fodder.

This uC has no internal Flash. Firmware is uploaded through DFU when Pulseview is started, so there is no copyright legal mumbo jumbo.

 

(almost ?) any development board for this uC works with Pulseview.

I usually recommend the "24MHz 8ch" search term because they come in a box and have input protection.

With a general development board for this uC you get 16 inputs, but no input protection (you can add your own).

https://www.aliexpress.com/wholesale?SearchText=CY7C68013A

 

Sigrok / Pulseview is also steadily growing.

New protocol decoders or hardware are added almost every month.

For example on 2018-06-12 support was added for the Hantek 4032L, with 400Msps and 32 channels (but probably not at the same time).

 

Some time ago I made a simple introduction and some screenshots on how I use Pulseview to debug software for AVR's:

https://www.avrfreaks.net/comment/2421756#comment-2421756

Having a buffer of multiple seconds of logged data, and then being able to go back in time to examine what happened just before your software encountered a bug is a very valuable tool.

 

The protocol decoders are also extremely usefull.

Raw Logic Analyser data is just a bunch of one's and zero's or squiggly lines.

With the protocol decoders you can easily make sense out of it.

The way of stacking protocol decoders in Pulseview is also a very usefull feature.

For example, you start by capturing an I2C bus ( 2 squiggly lines).

Then you add an I2C decoder. You have now read and write operations with addresses, and indications where your lines do not follow the I2C standard.

Then you stack an decoder for a real time clock on the I2C decoder. You have now instant overview of the data from your I2C clock.

In total Pulseview already has more than 100 of these decoders.

 

I also agree with Simonetta that the USD 5 "24MHz 8ch" is all that is needed for beginners.

It is perferct for all the serial protocols used by low end microcontrollers.

Out of curiousity I've used this hardware to capture and decode low speed USB ( 1500kbps) and it worked perfectly.

You can decode packets, T-states, handshaking, data, checksums, and you quickly get familiar wiht USB stuff you didn't even know existed.

 

In my opinion such a logic analyser should be part of each starter packet for people starting with microcontrollers.

It can take years for people who start with an "arduino" before they even hear of a logic analyser, and much longer before they realize how usefull they are.

 

For the more visually inclinded I'll link to a (very good) video of an introduction in Sigrok/ Pulseview and use of Logic Analysers in general:

https://www.youtube.com/watch?v=dobU-b0_L1I

Doing magic with a USD 7 Logic Analyser: https://www.avrfreaks.net/comment/2421756#comment-2421756

Bunch of old projects with AVR's: http://www.hoevendesign.com

Last Edited: Thu. Oct 18, 2018 - 08:31 AM
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Totally agree, this is definitely the most powerful tool you can buy for such low amount of money.