It does appear that 20 feet of cable will work for SPI. The length
is approximate, but I think it is close to 20'.
The speed at which I am communicating at though is a bit confusing
based on the documentation I am working with in the BASCOM manual.
If I am interpreting it correctly, I am communicating at 1/16 clock
speed. So 18.432 Mhz xtal 18,432,000 / 16 = 1,152,000 bits per
second.
If I understand everything correctly, this is very good news for
this project! Things just got a lot faster and better.
CHris
--- In Electronics_101@..., "lcdpublishing"
<lcdpublishing@...> wrote:
HI ROy,
In reality, I would have been very surprised had it worked! When
I
was first working out some serial communications software about 20
years ago, I used all short cables and PC-PC for testing. Then to
find the distance limitation with RS232, I had four, 1000 foot
spools of cable on hand. I started out with one spool, then two,
then on the third one it failed. At the time I had no idea why,
but
I was aware that having the cable on the spool was a "worst case"
situation.
Today's test I am going to cut off about a 25 foot section of the
cable I tried for SPI, and see if that works. If not, I will keep
cutting it down till it does.
--- In Electronics_101@..., "Roy J. Tellason"
<rtellason@> wrote:
On Sunday 30 April 2006 04:55 pm, lcdpublishing wrote:
Well, I know for sure what won't work!
I had a 100' spool of 24 gauge solid core wire handy with both
ends of
the cable exposed. I stripped off some conductors, spliced it
into the
bread board circuit for the SPI wires. No-go, so, now I know!
100 feet - too long for SPI ;-)
A bunch of wire on a spool is also going to have some
inductance,
there,
much more so than just a wire run to somewhere...
--
Member of the toughest, meanest, deadliest, most unrelenting --
and
ablest -- form of life in this section of space, a critter that
can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet
Masters"
-
Information is more dangerous than cannon to a society ruled by
lies. --James
M Dakin
