Author Topic: Logic Analyzer recommendation?  (Read 1683 times)

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Offline AdminTopic starter

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Logic Analyzer recommendation?
« on: October 12, 2010, 09:59:09 AM »
I'm looking for a small portable Logic Analyzer under $300 . . .

No specific needs, mostly generic, measuring I/O between multiple items simultaneously to verify they 'agree'. I'd need to measure 230400bps serial lines (about 2.3MHz sample rate needed), but probably nothing faster than that.

I've seen good reviews for the Salae, but there are a bunch out there . . . anyone with opinions?

http://www.saleae.com/logic/
http://www.nkcelectronics.com/zeroplus-lap16032u-logic-ana16032.html
http://www.usbee.com/sx.html
http://www.linkinstruments.com/mso19.htm

found interesting comments here . . .
http://hackaday.com/2009/03/06/tools-saleae-logic-logic-analyzer/

Offline KurtEck

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Re: Logic Analyzer recommendation?
« Reply #1 on: October 12, 2010, 12:41:31 PM »
I have the saleae version and it works great for me! Their new version of the software now works on Macs as well as well as Linux.  I have used them to help debug serial communications as well as SPI and I2C.

Their older windows only version has one feature that the new one does not have yet, which is to autobaud - Guess what the actual baud rate is.  Hopefully they will get that back into the newer multi platform version, but you you can still run either version...

Kurt

Offline z.s.tar.gz

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Re: Logic Analyzer recommendation?
« Reply #2 on: October 12, 2010, 10:04:05 PM »
Linux? Count me in!  :P
Seriously though I've been looking for a linux compatible one.
Save yourself the typing. Just call me Zach.

Offline Soeren

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Re: Logic Analyzer recommendation?
« Reply #3 on: October 13, 2010, 01:44:34 PM »
Hi,

No specific needs, mostly generic, measuring I/O between multiple items simultaneously to verify they 'agree'. I'd need to measure 230400bps serial lines (about 2.3MHz sample rate needed), but probably nothing faster than that.

A 3MHz sample rate won't catch short glitches and such. In my opinion, you can never get one that is too fast.

With Logic State Analyzers (LSA's) the most important specs are speed, number of channels and the controlling software.


I've seen good reviews for the Salae, but there are a bunch out there . . . anyone with opinions?

I recently spend numerous hours (if not days totally) to find the right LSA for me and I ended up with the Intronix' Logicport but it's a bit more than you want to pay. During the research, I compared numerous LSA's both their specs and their software.
We may have different needs in LSA's, but to me number of channels that can sample at max. speed should be high (some can only run at max. speed on a few channels).

I consider the Salea nothing more than a toy and it's far too expensive considering its specs.
24MHz sampling rate is laughable and don't get taken in by the large amounts of samples it can hold in one go - nobody is going to scrutinize several kilobytes so megabytes of storage is not really a competitive parameter IMO - max. sampling speed is important however and that it can work in both clocked mode and state mode (which most can these days).
The trigger voltage should be adjustable and it should be able to stand over-voltages on the inputs.

I considered the Open Workbench Logic Sniffer, as it's open source (and cheap, $45 assembled), but I found it too slow.
The design specs:
    *  70MHz+ sample speeds
    * 32 channels
    * 16 buffered, 5volt tolerant channels
More specs here
Apart from the speed, it sounds good and it's cheap and open source (and works with a free open source (IIRC) software).
You also need to consider what you may need somewhere down the road and not get something that just barely get you through your immediate needs. After all, it's not something you buy regularly.
Regards,
Søren

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Offline KurtEck

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Re: Logic Analyzer recommendation?
« Reply #4 on: October 13, 2010, 02:39:19 PM »
Hi Soeren,

The Intronix one looks like a nice one.

But for me the Logic one works great.  I never typically need to run it higher than maybe 1 or 2 mhz to catch most things I am interested in.  But I do like having large samples.  My last one was 10mb.  I was detecting what serial input and output was going from a Basic Atom Arc32 to a Lynxmotion SSC-32.  I start the program up, start the scan, Use the remote control to make it do something, after the event happens, that I am interested in, I can stop the scan and then check to see if the proper things were being sent back and forth.  In the case I was looking at this morning I was expecting two bytes back but only got one... 

Yes could get by with shorter samples, generate some test signal, set it as a trigger and the like, but this easy and I am lazy...

Whatever works...
Kurt

 


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