Hi John,.
On 29-08-12 15:47, John in WI wrote:
First off, a big thank you to this group... it has answers to many of my
questions and I've learned a great deal. The jal libraries are fantastic.
Thanks!
I am trying to take a decimal formatted byte (sent serial from a PC) and
convert that to turning on/off individual pins.
My 8 pins are on different ports.... 4 on portb 4 portc. Other pins on C
and B ports are being used for other, non output purposes.
Often, when I program in basic or c++ there are functions to format a
decimal byte to a string of 0's and 1's..... then, using string
functions like MID I pick out each bit and get it's value that way.
That is a very inefficient way to do things (in a PIC)! You better learn
how to handle individual bits in a byte! And it is not so difficult once
you understand it. Example:
var byte x = "A"
In ASCII notation the bit-pattern of "A" is 0b0100_0001 and that of "a"
is 0b0110_0001. So if you need to know if x contains a capital A or a
lowercase a then you could do something like:
if (x & 0b0010_0000) then -- check if bit 5 is 1
-- { whatever }
end if
And if you want to be sure that x contains a lowercase letter regardless
if it already uppercase or not then you could do
x = x | 0b0010_0000 -- set bit 5 to 1
Note: bits in a byte are numbered right to left from 0 to 7.
Hope you understand this, once you do: there are more interesting
bit-operations to learn!
I am not finding any way to format a decimal byte to a binary or ways to
pick out individual characters of a string with JAL.
The libraries 'Format' and 'Print' have conversion procedures.
Regards, Rob.
--
R. Hamerling, Netherlands --- http://www.robh.nl
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