pic microcontroller discussion list wrote:
> As with most things in EE, it looks like the answer to this question
> depends on your individual problems and design goals.

I think this about sums it up. It's always a tradeoff. Cost has been
mentioned already, but I feel like jumping in on this thread

Cost and complexity are almost always interrelated. Cost is more
than just component cost. I personally think that component cost
only becomes relevant when you start talking about 10's or 100's of
thousands of boards. I look at it in terms of design time e.g.
engineering salary. In this case, DigiKey price for 100 16F872-ISO
is $2.81. 100 12F629-ISO plus 74HC164 is 1.32. Difference is $1.49
times 100 units = $149 dollars. How much more it costs to design in
a shift register depends on many factors, but I doubt its more than
30 minutes to an hour even if you include PCB layout. As long as this
isn't your first PIC project, clocking out serial data is trivial. So
the cost difference shrinks to maybe $100. Its pretty much a negligible
difference at low volumes in any case. But at higher volumes, the
component costs start to make a difference.

In general, the simpler the design, the less can go wrong, the less
time it takes to design and develop, and the cheaper it becomes.
Unless you are doing it as a hobbyist, time is not free.

So, there is no right answer to the original question, just guidelines :)


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