printf() behavior

[cartic]

I am trying to send 32 bit integer(let's say as hex) from hyperterminal to PIC 16f877.
For example, let's say I send 0x30303030( characters 0000) to PIC.
I use 4 getc statements to receive and store it in an array.
And use make32 statement to convert the received four 8 bit integers to 32 bit integer.
When I print that 32 bit integer back using format specifier"%8x", it gives 00000030.
When I use "%8Lx", it prints 000030303030.
This is wierd. I would like to know, why this occurs. I have attached the code snippet with this post. I hope it helps.
Thanks for any help
cartic
[code]
void rst_tmr2(void)

{

int imsb[4];

int i,j=0;
char ctrl;

long int ind=0,count=0;

i=4;

while(true)

{

if(kbhit())
{

ctrl=getc();

goto b;

}

}

b:
if(ctrl=='h')

{

putc(ctrl);

while(i>=1){

j=i-1;

if(kbhit()){

imsb[j]=getc();

printf("%2x",imsb[j]);

i--;

}

}

}

a:
while(true){

if(kbhit()){

ctrl=getc();

putc(ctrl);

}

if(ctrl=='l'){

putc(ctrl);

delay_us(960);

cnt=0;

putc('c');

set_timer2(0x00);

putc(ctrl);

setup_timer_2(T2_DIV_BY_4,0XFF,15);

channel=12;

display();

// ind=8;

goto l;

}
}

l:
MSB=make32(imsb[3],imsb[2],imsb[1],imsb[0]);

LSB=make32(cnt,0,0,0);//variable reading the timer 2 count

printf("%8x%8x",MSB,LSB);

enable_interrupts(global);

enable_interrupts(INT_TIMER2);


}

[PCM programmer]

You need to convert your data from ASCII format to binary. In other
words, you need to convert from a text string to an integer.

It's obvious you're a student. We're getting a lot of student questions
on here lately. This is not to disparage you. Everyone is a student
at some point, or many times. But I want to let you know something
about the C language. Almost anything that you want to do as a
student has already been thought of, and there are ways to do it.
For example, you need convert a numeric ASCII string to an integer.
What you should do, is scan the list of available functions in either the
CCS manual, or the help file. There is almost certainly going to be
a function that will do what you need. In your case, it's the "atoi32"
function. Look in the manual for information on this function.
Also note the atoi32() operates on a string. A string is a series of
ASCII characters, with the last byte set = 0. That's a binary zero,
not an ASCII zero. The final 0 byte tells string functions that "this is
the end of the string". When you read in that value with several getc()
statements, you need to put in a line of code to insert a 0 byte right
after the last ASCII byte. Then the atoi32() function will operate
properly.


Also, when you're posting code, you should not double-space every line.
Tto use the "Code" format button, you need to highlight all your code,
and then just click the "Code" button once. Then use "Preview" to check
that it's done properly before you press "Submit".

[Mark]

remember that
%x prints an 8bit hex number
%Lx prints a 16bit hex number

[cartic]

Thanks for the replies, You are right, I am student doing my project using PIC C. I already browsed through the manual and know about the atoi function, but I did not use the atoi() function at all. I am just sending 32 bit hexadecimal number to PIC, make PIC receive it as integer and print it back.
I am not doing any type conversion at all.
But my doubt was why is it printing the same number in weird manner, when only the format specifier is changed from %8x to %8LX. when I send 30303030(32bit integer), if I print back as %8x or as %8LX, it should print the same answer, but with zeroes added or without the zeroes, but the entire answer should not differ, right.
using format specifier"%8x", it gives 00000030.
When I use "%8Lx", it prints 000030303030.

If you addressed the same point,can you pl. make it a bit more clear. The second reply was somewhat relevant but, I still did not get the expected reply or may the reply in manner in which I can understand.
thanks
cartic

[Humberto]

Hi cartic,

For your info, PCM programmer and Mark are two of the best contributors that
this board have and the answers they gave you are rigth in all sense, if you
don´t understand them, -without being offensive- did you think the possibility
that you will need to learn a little more C ?

Reading your code it´s obvious that you are learning, it´s plenty of "goto" that,
-I agree it´s a valid C statement - I´m sure you will eliminate as soon as you
learn how to use another statements.