Conversion of char for hexa!?!?

Friends, I have a function that it prints an image from an variable of the type byte.

Code:

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 byte xRPrint []  = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 PrintImage((byte *)xRPrint, 5, 128, 8); //function print image

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until there all good

only that I go to send the content of the variable of a server, for socket in one string, Ex:

Code:

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char xImage[] = "0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00"

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as I make to catch the content of xImage and to place in each position of xRPrint

observing the value of string " 0x0F" and placing in the same position the referring value in hexa

understand?
it forgives my English!

thanks!

You need to turn the string back into a bunch of numbers. The underlying bit pattern for a number is different than the pattern for a glyph like 'A' or 'B' (which are both hex digits, bear with me).

There are C functions available to help you with your task. The easiest of which I can recommend is strtol. strtol, as implied by the name, takes a string and a radix, and attempts to convert the string data to a number representation.

You should look it up and devise a method to help yourself.

I made a demonstration for you, take a look with your debugger:

Code:

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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

int main ( void )
{
    const char * receev_me = "0xDE 0xAD 0xBE 0xAF 0x00";  /** some data **/
    char * receev_me_pos = NULL;
    unsigned long i = 0;
    unsigned char converted[16];  /** a big enough space to hold actual bytes**/
    int done = 0;                /** loop control **/

    /** set to all bits zero **/
    memset( converted, '\0', sizeof converted );

    /** parse the hexa bytes with strtol **/
    while ( !done ) {
        unsigned char byt = ( unsigned char )strtol( receev_me, &receev_me_pos, 16 );
        /** strtol will point to where conversion ended. **/
        /** if the number was done sucessfully, try to store it. **/
        if ( receev_me_pos != receev_me && ( isspace( *receev_me_pos ) || *receev_me_pos == '\0' ) ) {
            if ( i >= sizeof converted ) {
                fprintf( stderr, "No more room to store converted data!!!\n" );
                done = !done;
            }
            converted[i++] = byt;
            receev_me = receev_me_pos;
        }
        else {
            /** normal completion - nothing to parse **/
            done = !done;
        }
    }
    return 0;
}

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This may or may not be exactly what you are looking for but I'm confident you'll go far with this help.

accurate, it was this same, it correctly printed as img printed in the format

Code:

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byte [] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}

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tnx tnx tnx!!!!
;)