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Thread: Programming a 16f84 vs 16f877
www.piclist.com/techref/microchip/devprogs.htm?key=programming
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face BY : John J. McDonough email (remove spam text)



----- Original Message -----
From: "Shay" <spamBeGoneshayspamhighstyleweb.com>
Subject: [PIC] Programming a 16f84 vs 16f877


> found.  I still haven't figured out what chip I should start with but am
> now leaning towards the 16f877.

Shay

Neither I, nor anyone else, responded to this comment.

As both Olin and I mentioned, moving between the various 16F's really isn't
much of an issue.  The 877 is a fairly old chip, and it is kind of
expensive.  But it does give you lots of pins to play with, and pins are
resource you typically run out of first.

As I mentioned in an earlier post, one thing you have to do with most parts
is some initialization of various I/O devices.  On most PICs, every pin has
multiple functions.  If you are just learning, this can get pretty
confusing.  The 16F84 is a sort of special case.  Only one pin has multiple
uses and it defaults to the same behavior as the other pins.  So getting
started, the 84 is a little easier than most of the others.

On the other hand, the F84 is close to, if not the most expensive 18 pin
part.  Almost every other 16F has more stuff (memory, I/O) at a lower price.
Once you get you head around the initialization of the various I/O devices,
almost any other part is a better choice.

If you are on a program of learning the PIC, I would suggest buying a 16F84
and a 16F628.  Do some simple stuff on the 84, then port it to the 628.  The
628 has more memory, and a few pins have the additional I/O initialization
to worry about.

Once you are comfortable with those, then try the same sort of exercise on
the 87x series.  This is a really neat group of parts.  The 87x parts are
very similar.  They only differ in the number of pins and memory size.
(Well, the 872 lacks one I/O device ... I don't recall offhand what it is).

The 84, 628, and 87x (but not the A versions except for the 84) are
supported by the widest range of public domain software.  However, newer
parts like the 16F88 have some pretty neat features.  So as you get set up,
think about those other parts.  If you arrange to have some flexibility in
your development environment, switchnig between chips is pretty simple
business.  And then you can spend only as much as you have to for the PIC in
your projects.  Plus, sometimes you see a really good deal on something.  If
you have more flexibility in what you can use, you can take advantage of
more of those deals.

If you are not put off by the price, get an ICD2 for programming and
debugging.  If the price scares you, build or buy an in-circuit programmer.
There are a million designs you can build for under $20 (if your PC has a
REAL serial port).  Programmers like Wouter's Wisp628 or Olin's EasyProg are
inexpensive to buy, too.  I think both are still under $40 if you include
shipping, and they free you from the "real serial port" limitation.  If you
buy a Wisp pick up a few PICs from Wouter too, and save a separate shipping
bill.  Programmers with their own socket may look neat, but operationally
they are a real hassle.  Read the ICSP document on Microchip's website and
do things that way.  It makes life a lot easier.

--McD

<007c01c5e921$11b20880$120044c0@Aidan> 7bit

See also: www.piclist.com/techref/microchip/devprogs.htm?key=programming

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