Some examples

A short, but complete example to give a first impression:

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

#include "serdisplib/serdisp.h"   /* include all important header files */

int main(int argc, char** argv) {

  char sdcdev[] = "/dev/parport0";  /* use parallel port */
  /*char sdcdev[] = "/dev/ttyS0";*/  /* use serial port */

  char dispname[] = "PCD8544";  /* display name */

  serdisp_CONN_t* sdcd;
  serdisp_t* dd = 0;
  int i;

  /* opening the output device */
  sdcd = SDCONN_open(sdcdev);

  if (sdcd == (serdisp_CONN_t*)0) {
    fprintf(stderr, "Error opening %s, additional info: %s\n", sdcdev, sd_geterrormsg());
    exit (1);
  }

  /* opening and initialising the display */
  dd = serdisp_init(sdcd, dispname, "");
  if (!dd) {
    SDCONN_close(sdcd);
    fprintf(stderr, "Error opening display %s, additional info: %s\n", dispname, sd_geterrormsg());
    exit(1);
  }


  /* turning on backlight */
  serdisp_setoption(dd, "BACKLIGHT", SD_OPTION_YES);

  /* clearing the display */
  serdisp_clear(dd);

  /* draw a border (only internal display buffer is affected!!) */
  for (i = 0; i < serdisp_getwidth(dd); i++) {
    serdisp_setsdcol(dd, i, 0, SD_COL_BLACK);
    serdisp_setsdcol(dd, i, serdisp_getheight(dd)-1, SD_COL_BLACK);
  }
  for (i = 1; i < serdisp_getheight(dd)-1; i++) {
    serdisp_setsdcol(dd, 0, i, SD_COL_BLACK);
    serdisp_setsdcol(dd, serdisp_getwidth(dd)-1, i, SD_COL_BLACK);
  }

  /* commit changes -> update the display using the internal display buffer */
  serdisp_update(dd);

  /* wait 30 seconds */
  sleep(30);

  /* shutdown display and release device*/
  serdisp_quit(dd);

  return(0);
}

Open display, draw something, and exit without clearing the display:

  /* initialising, a.s.o.: see example above */
  ...

  /* draw something */
  ...


  /* commit changes -> update the display using the internal display buffer */
  serdisp_update(dd);

  /* release display without switching it off / clearing it */
  serdisp_close(dd);

  return(0);

Open display as in example 1, but use default identifier function:

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

#include "serdisplib/serdisp.h"   /* include all important header files */

int main(int argc, char** argv) {

  char*  sdcdev = 0;

  char dispname[] = "PCD8544";  /* display name */

  serdisp_CONN_t* sdcd;
  serdisp_t* dd = 0;

  /* some initialisation code */
  ...

  /* opening the output device */
 
  if ( ! (sdcdev && strlen(sdcdev) > 0 ) ) {
    /* if sdcdev is empty: use default device identifier for this display */
    sdcdev = (char*) serdisp_defaultdevice(dispname);
  }
  sdcd = SDCONN_open( sdcdev );

  if (sdcd == (serdisp_CONN_t*)0) {
    fprintf(stderr, "Error opening %s, additional info: %s\n", sdcdev, sd_geterrormsg());
    exit (1);
  }

  /* opening and initialising the display */
  dd = serdisp_init(sdcd, dispname, "");
  if (!dd) {
    SDCONN_close(sdcd);
    fprintf(stderr, "Error opening display %s, additional info: %s\n", dispname, sd_geterrormsg());
    exit(1);
  }

  /* do some stuff */
  ...

  /* shutdown display and release device*/
  serdisp_quit(dd);

  return(0);
}