/*
 * test_changing_digismoke_map: test, if the map in digismoke can be
 * changed
 * If compiled with -Drestore the original map is restored.
 * If compiled with -Dcostom a new map is installed. It consists only of two
 * phases: <50% off, >=50% on.
 * This code was written to demonstrate how to change the map. It depends on
 * one a DMX512 Interface like USB2DMX-primo, LPR2DMX2 or LPR2DMX.
 *
 * Be sure to switch to address 555 befor expecting results.
 */
 
#include <stdlib.h>
#include <stdio.h> 
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#define DEVICE "/dev/usb/usblp0"   /* which device?
				      for LPR2DMX or LPR2DMX2 use /dev/lp?
				      where '?' is the number of the parallel
				      port the device is connected to */
void main()
{
  int f = open(DEVICE, O_WRONLY);  /* open device to write to */
  int i;

  unsigned char buf[2+1+64+4];
  
  if (f == -1) {
    fprintf(stderr, "Error: can't open device\n");
    exit(0);
  }
  
  buf[0] = (sizeof(buf)-4) >>8;    /* prepare writting to USB2DMX-primo or */
  buf[1] = (sizeof(buf)-4) & 0xff; /* LPR2DMX, LPR2DMX2 */

#ifdef restore
  buf[2] = 80;                     /* start-code to restore */

  buf[3+0] = 0x55;                 /* spezial bytes to start the writting */
  buf[3+1] = 0xaa;
  buf[3+2] = 0x55;
  buf[3+3] = 0xaa;
#endif
#ifdef costom
  buf[2] = 90;                     /* start-code to costomize the map */

  for(i=0; i<64; ++i)              /* create new map */
    buf[i+3]=(i/32)*0xff;

  buf[3+64+0] = 0x55;              /* spezial bytes to start the writting */
  buf[3+64+1] = 0xaa;
  buf[3+64+2] = 0x55;
  buf[3+64+3] = 0xaa;
#endif

  while(1)                         /* write the buffer continuosly */
    write(f, buf, sizeof(buf));
}