On Sat, Mar 13, 2004 at 11:54:41PM -0500, Robert L Cochran wrote:
> >I ordered a set of chips over a month ago. They still haven't been shipped.
>
> The same will probably happen to me.
>
>
> >Understood. However the similarities of all the parts in this family is
> >what
> >binds them together. At the low end they are pretty much interchangable.
> >I always suggest to hobbyist to start with the most featured chip and then
> >work their way down. That gives the opportunity to see all the cool
> >features.
>
> I need to learn how to use these features. I consider myself to be lucky
> that my 16F84A will actually turn LEDs on. In fact, I'm congratulating
> myself for it.

As am I. It's a good start.

It's the educator in me that wants to think through to the final objectives
of a course of study. Blinky LEDs is where you start. But your choice of
chip has a strong influence on where you can end up.

>
> >
> >Nigel Goodwin's Winpicprg tutorial suite is pretty good about showing the
> >capabilities of the more featured members of the 16F family. They are based
> >around the 16F628, the 16F876, and the 16F877. It's still not as up to date
> >as the latest chips, especially the ones with nanowatt capability. But it's
> >quite an advance over the 16F84. You can find it here:
> >
> >http://www.winpicprog.co.uk/pic_tutorial.htm
>
> I've bookmarked it. Thanks for pointing me to that because I can use the
> tutorials. Do you happen to know any with photos that show how to use a
> digital multimeter?

Not a one. But a verbal explanation should be simple enough. Digital
multimeters generally have 3-6 functions:

1) Voltmeter (both AC/DC)
2) Resistance meter
3) Ammeter (measures current)
4) Contiunity (Actually an extension of #2)
5) Diode polarity
6) Capacitance meter

Most simple multimeters have the first 4 functions, while more featured units
may contain the last two, which I'll skip for this discussion.

There are very few rules of thumb when using a meter:

1) Ground the black lead when measuring DC voltage. For AC it doesn't matter.
2) Never meature resistance/continuity with power applied as the meter uses
   a voltage to determine the resistance.
3) Measure current by putting the meter in series with circuit you wish
   to test. So the meter becomes part of the circuit.
4) Be sure to follow specified time/max amps listed on the meter when
   measuring current.
5) Be aware that a meter will have a tough time measuring anything that isn't
   relatively steady. So it isn't the right tool for fluctuating values.

That's about it. If you have any more questions, feel free to ask.

>
> I'll resume my big project tomorrow morning (Eastern time) -- building a
> ZIF socket-based 'PIC on a board' (as described by Benson) using that
> Datak protoboard. Since my socket is 40 pins maybe I should pay
> attention to wiring it to be compatible with the newer PICs you are
> pointing me to.

Actually all of the parts I've been discussing are 18 pin parts. That was
triggered by the 16F84A reference.

I still haven't really found a part that meets all of my needs in the 40 pin
size. There is no 16F88 equivalent. I thought that the 16F777 was going to be
the winner, but it turns out that it isn't self programmable, so it's not
possible to put a bootloader in it. BTW with a bootloader, a program on the
part that accepts and writes other programs into the part's memory and
executes them, you don't need a real programmer anymore. I find them invaluable
for my development cycle.

The closest 16F part in the 40 pin variety is the 16F877A. But I'm hoping that
Microchip will release a 40 pin version of the 16F88 soon.

BAJ

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