Done

The last LA I built used a CRO as the display. By feeding the data to an R2R network and modulating the Z input I was able to get quite a nice display with blanking and a bright cursor. IIRC it used about a square foot of perf board and had almost no features

These days I'd day feed the data to a PC and write something in VB.net

Here's a couple of well known ones

http://www.sump.org/projects/analyzer/
http://antoniak.ep.com.pl/index.php?id=sla

Check this out.

http://gabotronics.com/development-boards/xmega-xprotolab.htm

Hi Rob,

That was quick! I had a look at last link - xprotolab - it looks like a neat unit and if $35 is correct, then it is cheap at half the price. I'll check out the other two links a bit later.

Still, I wouldn't mind designing one from first principles - not yet though, I still have that B....y AVR programmer to finish.

How does one go about doing graphics in VB? e.g. square waves.

d.m

There's no way to justify it on a $ basis, but it would be a fun project, of course it would be easier to build if you already had a logic analyser


Now that you mention it I don't think I ever have, but there is a full compliment of graphics commands so it wouldn't be hard.

Hi Rob,

I had a look at the first two LA links - I like the look of the second one - it looks like it wouldn't be too difficult to build. Getting the SRAM chip might need a bit of a search, the rest should be freely available.

Reckon I'll have a go at it - if for no other reason than it will be a venture into VB6 graphics. Once again though, it'll have to be after the AVR prog project. BTW I have the pic interface software written and working, I just have to hook it up to the AVR.

d.m

Just found another one

http://www.ikalogic.com/scanalogic2/index.php

And their DIY page with schematics

http://www.ikalogic.com/scanalogic2/build.php

Hi Rob

A nice looking unit - pity it needs a preprogrammed MCU - still, I suppose that given the schematic, it wouldn't be too hard to come up with a functioning unit. Yair I know!! You can buy these things 'dirt cheap', so why bother doing the hard yards... I guess its because we can, as well as get a kick out of saying 'well, I beat you, you b....'. And amazing what we learn in the process.

I've downloaded the schematic in any case for a closer look.

d.m.

I've got no problem with DIY, it's a lot of fun making something regardless of the financial implications.

I can't quite figure what the four chips are at the top of the schematic, serial RAMs?

They look like it - I see all chip selects are tied together but data on each chip goes to different places. Also, there is only 4 lines in, so it looks like 1 ram chip per channel - one way of speeding up acquisition I guess. I think I go have a look at the parts list on the link.

I think I'd prefer to use 'standard' byte wide ram chip - faster and randomly accessible - not that that would be necessary as it would receive a stream of data and the data would be displayed sequentially anyway. It would give 4 more channels though.

d.m.