#include <stdlib.h>
/* assume two hex chars per ascii value */
void hex2ascii(char *dest, char *src){
      char tmp[4]={0x0};     
      char **ptr=NULL, 
           *buf=dest;
      *buf=0x0;
      if(*src){
          for(int i=0;src[i];i+=2){
              strncpy(tmp,&src[i],2);
              sprintf(tmp,"%c",strtol(tmp,ptr,16) );
              *buf++=tmp[0];
          }
      }
      *buf=0x0;   
}