At 09:07 AM 9/20/2011, V G wrote:

>You're not the first. I found it a long-ass time ago. I can't stand that
>site.

You know, VG, that you are starting to look like=20
a really bad imitation of Olin Lathrop, except without his smarts.

You are definitely entitled to your own=20
opinion.  However, I really don't like it when=20
you slam somebody for no particular reason.


For what its worth, I purchased two of those=20
little, really inexpensive 32 channel logic=20
analyzers.  They provide astonishing performance for mere peanuts.

I've mentioned them on the PIClist previously,=20
but here is a repeat of that information:

<copy begins>

I don't know if you have come across something=20
called the Open-bench Logic Sniffer (OLS) but its=20
an open-source logic analyzer based on a PIC and=20
a FPGA.  Its good for up to 32 channels but the=20
board itself contains only enough 5V-tolerant=20
buffer inputs for 16 channels.  The other 16=20
channels are brought out to headers: you can use=20
them directly for 3.3V signals or add on an=20
inexpensive daughter board containing another channels of 5V-tolerant buffe=
r.

Here's the kicker: it costs $50 including=20
shipping to anywhere in North America (and most=20
of the rest of the world).  Probe sets cost an=20
extra $6 per input cable of 8 clips +=20
ground.  The daughter-board adding 16 more=20
buffered input channels is an extra $15.

Although the firmware is currently evolving, the=20
current stable firmware is eminently=20
usable.  There are two distinct software=20
platforms available for it: SUMP and something=20
expressly designed for the OLS by a forum member with username of jawi.

The first shipping version has FPGA code written=20
by somebody who is not particularly=20
experienced.  It works but the performance is=20
less than what is actually possible.

The current beta firmware was written by somebody=20
who actually designs large FPGA systems for a=20
living.  He has apparently gotten almost all of=20
the features of an Agilent HP 16550a analyzer into the unit.

Short-list of specs: single-data-rate (max) 100=20
MHz, double-data-rate sample rate (max)  200 MHz,

Here's the new firmware author's take on what he has done:

"My version of the fpga uses 85% of the slices,=20
keeps the legacy triggers, meets timing easily (at 105Mhz), and adds:

Trigger Terms:
10 more 32-bit masked value comparisons.
2 range checks.
2 edge checks (rising, falling, both, neither).
2 36-bit timers (10ns to 600sec range).

States:
16 state FSM
Each state can use any combination=20
(AND/NAND/OR/NOR/XOR/NXOR) of the trigger terms=20
for detecting a =93hit=94 condition, and =93else=94 condition, or =93captur=
e=94 condition.

Each state also has a 20-bit hit count that must=20
be reached before a full =93hit=94 occurs. Hit=20
actions include setting trigger(run),
starting/stopping timers, and advancing to the next state.

The =93else=94 condition lets you punt to another state.

The =93capture=94 condition lets you control what=20
gets sampled into RAM, until you flip the trigger.

=85Grab the 16550a user=92s guide. I think you'll be=20
surprised how much got squeezed in."

Overview: <http://dangerousprototypes.com/open-logic-sniffer/>
In-depth description:=20
<http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer>
Even more hardware detail=20
<http://dangerousprototypes.com/2010/02/25/prototype-open-logic-sniffer-log=
ic-analyzer-2/>
Stable firmware:=20
<http://dangerousprototypes.com/forum/viewtopic.php?t=3D1780&p=3D17226>
Beta firmware: <http://dangerousprototypes.com/forum/viewtopic.php?f=3D23&t=
=3D1711>
Windows software:=20
<http://dangerousprototypes.com/forum/viewtopic.php?f=3D57&t=3D1198>
ordering:=20
<http://www.seeedstudio.com/depot/open-workbench-logic-sniffer-p-612.html?c=
Path=3D174>

There is also a download available for the SUMP=20
software - I can find that for you if you want.

Bottom line: you get a REALLY full-featured logic analyzer for peanuts.

I've been using mine since last fall and I'm=20
thrilled with it.  I can finally retire my ancient Tek unit.

dwayne

PS - these are the same guys who designed the Bus=20
Pirate that a lot of us have been using to do a=20
myriad of prototyping projects with.

dwayne


--=20
Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
www.trinity-electronics.com
Custom Electronics Design and Manufacturing


--=20
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