Logic Analyser Thread

[guddler]

I thought I'd start a new thread since the old one was getting somewhat off the point of the OP !

My cheap of cheap analysers hasn't turned up yet, probably another week or more I guess. Somehow today I've been distracted looking at the "Maker Bot - Thing-O-Matic" 3D printer which looks quite cool in it's own right. Anyway, I was looking through examples of what people had made* and I came across a case for the "Open Workbench Logic Sniffer" and off I went wondering what that was all about.

Well, I've no idea if the spec's are any good, but it's a 32 channel unbuffered, 16 channel buffered logic analyser for the princely sum of $50. Yes, $50 !!!

http://www.seeedstudio.com/depot/preorder-open-workbench-logic-sniffer-p-612.html?cPath=75

The software, however, does look kinda sucky:

http://www.sump.org/projects/analyzer/client/

I might be wrong, but I think the whole lot, hardware and software is open source though so maybe some way to do something about that?

Are the specs any good?

* I would guess the case had been made with a different make of 3D printer as it was clear acrylic that had clearly been laser cut, not built up in layers of ABS.

 

[guddler]

Actually, on the hardware page there's a link with a couple of videos and while the software's look and feel is a bit on the sucky side of things (it's Java, it's kind of to be expected!) it actually covers most of what you need:

Multiple triggers based on any mask of any of the channels

Same rate / buffer length

Cursor readouts

Al the main food groups, no?

 

[trm]

I think that started out on hackaday.com a couple of years ago and has clearly been refined as well as somebody agreeing to make a production run. The spec is pretty impressive. The software also look way better than it did when I first saw it so I'd guess it'll probably carry on improving now that you can buy the ready made board instead of hunting down a specific (no longer produced) Spartan dev-board and the user base grows.

As for replacing the UI, the comms protocol is serial and documented here

http://www.sump.org/projects/analyzer/

as is the VHDL for the LA itself.

One of the very nice features is the sample depth: even when using 32 channels you've got 4/6k (I suspect they'll upgrade from the current 4k depth to the max 6k with a future code upgrade for the FPGA) samples whereas the Intronix only has 2k per channel regardless of sampling rate (the Intronix does do some form of compression on the sampling - I suspect only storing transitions and not every sample) so I don't know how the actual bench test result would compare if the OWLS stores a sample at every interval, but whatever it's still $300 cheaper!

Plus you seem* to have got all of the code behind the system so you can hack away. Add state change sampling, optimise the code a bit to up the sample rates and so on. Probably quite an interesting way to get into VHDL.

* I say seem as the original sump.org page doesn't quite match what the retail outlet is saying so I don't know if the project has been forked as the hardware you can buy is closed source.

 

[guddler]

It's certainly interesting. I need to let the dust settle on all my recent household stuff (quite literally!) but I may be tempted afterwards...