Hi McGuinn,
Thanks for your interest, and i did look up that stuff about
tones. I had thought that the major problem would be making
something that could put the date/time on to tape (or whatever
medium). It now turns out that creating the date/time needed
such a high level of technology that turning it back to audio
in order to record it to cassette is effectively a backward
step, using the arrangement necessary to create the date/time
to further create additional control mechanisms is more in
keeping with the desired end result.
That is, a record of events and actions around my home, having
this in an electronic form for my PC and also printed on an
old printer (maybe later on a till roll). Using a PIC and also
some support chips running from the supply and the box that
would have to be made to create the date/time information, is
i now think a much more practical proposition.
So really the nature of this project has actually altered by
discussing it here on these forums. Unfortunately i cannot
alter the thread title, but now its more a case of me stumbling
along into PICs, a direction that i did not foresee.
Now that i am starting to realise what they are, i am getting
more and more fascinated by them.
Hi Nigel,
Well ive been reading up on these PIC devices, the more i read
about them, the more they remind me of the Zilog 8080-A, they
seem to be rather like a slow running PC chip, i may be wrong
but i think they use clock speeds of one microsecond, okay its
not that slow i spose.
Years ago i went through a phase of trying to program an 8080
in assembler, i did a little bit of moving letters around on
the monitor, then i got frightened off cos i didn't really
follow the architecture.
Now i find that these PIC chips use a 'Reduced Instruction Code
Set' so maybe i could get to grips with the PIC system of
shuffling 'words' between registers till it comes out right.
Apparently the instruction set is thirty odd instructions,
i wonder if its not too difficult to learn how to use it, at
a machine code level.
Your mention of 'allocate a pin for each input' has me quite
confused, unless you mean on the integers (2,4,8,) i'm still a
bit lost on that ...
And i am a bit concerned about the overlap of incoming signal
times. As it stands, the incoming signals light lamps, and some
ring bells. If two come in close together, thats ok, two lights
is ok. But for the electronics it might not be ok. Maybe i
should arrange that any incoming signal would only feed a mille
second pulse to the electronics, in the unlikely event that two
such signals arrive together, then one would be lost.
Unless there is a way to respond that i haven't thought of.
The lights or bells would still work anyway, so it wouldn't get
missed.
I would like to ask about the programming of the PIC, i assume
that is erasable and not permanent?
And would i need to make some kind of rig to 'implant' the
programming?
I had to make a 'rom' unit years ago for programming rom chips
i used to run seven segment displays off them directly on the
output lines, i think i coded the inputs for the 8+2 binary
from early counting chips. It made for an easy count and display.
I am still reading up on these PICs but basic info is not
easy to find.
John