[Elecraft] PIC Programming Book

[Brian Alsop]

Lee and Jeff,

By registers, I think you are referring to those bits which must be set 
to select the various options a particular PIC pin may be used for.
(If not skip the rest of this posting.)

Setting these registers is the bane of PIC programming.

There is a tendency for the programming documentation to send one to the 
nearly incomprehensible device spec sheet for details.  It varies from 
device to device.  These sheets usually give examples in assembly 
programming which really don't help the common man much.

The real solution seems to be to find a bit of coding that does 
something similar and use it as guidance.

Some of the problem is with the compiler used to generate the hex code. 
  Some are smart enough to set some or all of the registers for one, 
some are not.

If one is just fooling around trying to get one's feet wet in PIC 
programing then the PIC-AXE series of devices are ideal.  There is a 
free BASIC language compiler.  There are no registers to set!  The price 
per device is in the $5 to $10 price range. They are in circuit 
programmable so one doesn't need separate hardware to do the 
programming.  I just finished up rotor control box using one of their 
low end chips.

One might think that these devices can't do much.  Not so.  How about:
12 bit A/D converters (many/chip), D/A, RS232 I/O, IR device I/O, 
keyboard and keypad input, servo output, temperature read routines, + 
lots more.  Most are accessible with one or two line commands.  No 
registers to set!

We've fooled with here are the PARALLAX PIC's.  Easy like above and in 
circuit programmable.  Also no registers but $50 and up per chip is a 
barrier.

Then there is the MIKROBASIC suite of programs and compilers (BASIC,C, 
PASCAL, assembly) for 16F type chips (actually it encompasses the entire 
family through 40 pin PICS).  One can do a lot with the free versions of 
their compilers.  It requires a separate programming board and is geared 
to more high end chips/applications.  Documentation is decent and has 
lots of examples.  I made up a custom and software programmable antenna 
switch box using one of the 40 pin PIC's and the K3 BCD band data 
outputs.  Registers have to be mostly set by the user but some typical 
defaults are contained in device dependent chip files.

Here are some links:

http://www.mikroe.com/forum/
http://www.rev-ed.co.uk/picaxe/

It is totally amazing what can be done with a few bytes or RAM and a few 
K of ROM.  Once logic can be built into a chip, a whole world of 
possibilities open up.

BTW, I'm just an amateur with all the above.  It does take some (or a 
sometimes a lot of) muddling through to get there.

73 de Brian/K3KO

On 2/11/2011 13:59, Lee Buller wrote:
>
>
> My friend, Jeff, who is not ham (His wife is...go figure) is a computer Linux
> geek and is trying to figure out how to program PIC computers.  I told him the
> other day that some Hams use them all the time in projects.  Not me...but some
> hams do.
>
> He is having some issues with finding information about registers.  I wonder if
> the people on the list could point me to books, manuals, information concerning
> the programming of PIC devices?
>
>
> Lee - K0WA
>
>
>   In our day and age it seems that Common Sense is in short supply.  If you don't
> have any Common Sense - get some Common Sense and use it.  If you can't find any
> Common Sense, ask for help from somebody who has some Common Sense.  Is Common
> Sense divine?
>
> Common Sense is the image of the Creator expressing revealed truth in my mind.
> -  John W. (Kansas)
> ______________________________________________________________


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