29 Jun
2004
29 Jun
'04
9:22 p.m.
In message <m1BfVfH-000IxtC@p850ug1>
ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
In which case I suspect this analyser with kludged
pods will be good enough.
The problem being that grabber probes tend to be rather
expensive - the
cheapest I found were ?1 +VAT, and they weren't particularly well made
either.
The SMD parts for the pods are cheap enough (?3 +VAT for enough parts to
build up 50 single-channel pods), IDC cable is easy enough to get, but the
grabbers are a bit too expensive. If I could get a few good-quality grabbers
for around 50p each...
I might just build a few interface pods with a 20-way IDC connector on the
output - fit an IDC20 to the target board, then just plug the analyser
straignt into the board.
I've been improvising with bits of solid core wire and 150K resistors. So far
I've managed to probe the 1-wire bus on an iButton-based lock, but that's
about it. I still need to test the other data channels on the analyser...
That's what the Elektor analyser consisted of.....
Yeah, I saw that. A few FIFOs and an Atmel MCU. I didn't build it because
there was no binary or source code available for the MCU and the software was
crap.
FWIW, I do a lot of my work with a 3 channel logic
analyser (HP
LogicDart),
Isn't that the handheld analyser that HP used to make? ISTR they
sold the
design rights to Fluke - I've seen them listed in the Farnell catalogue under
the heading "Fluke LogicDart handheld logic analyser".
and I find that to be enough. Often all I need to look
at is
one signal against an enable or something like that. Actually, a
single-channel analyser is sometimes enough.
I used to use a PC to do basic logic
analysis - the adapter was a DB25
connector connected to a few flying leads, with 47k resistors between the
leads and the connector. It worked reasonably well, but it kept missing
samples.
--
Phil. | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB,
philpem(a)dsl.pipex.com | ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.dsl.pipex.com/ | 48xCD, ARCINv6c IDE, SCSI
... Flash Gordon exposed himself to all sorts of danger.