> I chose the PIC16c84 because it was the chip that uni had the most
> information on, other than that there is no reason for using that
> particualr chip.

It's really a dinosour you should put behind you.  I don't know who or
what "uni" is, but Microchip has plenty of information about all the PICs
on their web site.

> The voltages will be between 0v and 0.5v.

That's pretty low.  Use an opamp to scale the max valid voltage to 5V.
This will give you impedence buffering at the same time.

> There will be up to 8 inputs.

Take a look at the 18F2320.  It has 10 A/D channels in a 28 pin package.
This is a very new part, and there seem to be some early problems with
this subfamily (some question about running at full speed, I am getting
burned by this right now).  If you don't want to be a test pilot, you will
need a 40 pin part to get 8 channels.  If this is a one off or small
quantity, I recommend the 18F452 because it is a good chip to learn and
will be useful for lots of other projects.  If you want to stick with the
16 family, try the 16F877.

> I need the outputted byte stream to tell the PC which input source it is
> looking at and whether it is high or low, for each of the sources in
> turn, running in a loop. E.g. 0011 would mean source 1 is high and 0100
> would mean source 2 is low.

That's easy.  All you need is a PIC with a UART, which all the ones I
mentioned above have.


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