/***************************************************************************
 *                        C SAMPLE #2 SAMPLE2.C                            *
 *                                                                         *
 *  This sample will generate 3 different wave forms, sine, triangle and   *
 *  saw tooth.  The user has the choice of base address, DAC number and the*
 *  number of points per cycle.                                            *   *
 *                                                                         *
 *  The following setup of the board is expected:                          *
 *      -- Base address should be set to the address entered during        *
 *         program execution.                                              *
 *                                                                         *
 ***************************************************************************/

#include <math.h>
#include <conio.h>
#include <stdio.h>
#include <dos.h>

#define  PI    3.1415927

unsigned counts;            // number of points per cycle
unsigned Address;           // board base address
unsigned dacnum;            // DAC used for output
unsigned progstruct[20000]; // buffer to hold points

void sendtoport( void);
void setparms( void);
void sinecurve( void);
void sawcurve( void);


unsigned AskForBaseAddress(unsigned int OldOne)
{
	char msg[7];
	int NewOne = 0, Success = 0, Dummy;
	int AddrInputPosX, AddrInputPosY;

	puts("\nPlease enter the Base Address for your card (in hex)");
	printf("or press ENTER for %X.\n>", OldOne);
	AddrInputPosX = wherex(); AddrInputPosY = wherey();
	do {
     gotoxy(AddrInputPosX, AddrInputPosY);
     clreol();
     msg[0] = 5; msg[1] = 0;
     cgets(msg);
     sscanf(msg + 2, "%x", &NewOne);
     Success = 1;
     Dummy = NewOne;
     if (msg[1] == 0) {
       gotoxy(AddrInputPosX, AddrInputPosY);
       printf("%X", OldOne);
       Success = 1;
       Dummy = OldOne;
     }
	} while(!Success);
	return (Dummy);
} // end of AskForBaseAddress

void setparms()
{
   char ch;

   clrscr();
   Address=AskForBaseAddress(0x300);
   //clear output voltage restrict - allow ref to reach non-zero volts
   outportb(Address+0x10,0x40);
   do {
      gotoxy (1,7);
      clreol();
      printf("Enter the DAC number you wish to output to (0 - 7 only): ");
      ch=getche();
      dacnum=ch-'0';         // using ascii code to get dac_number
   } while (((int)dacnum < 0) || ((int)dacnum > 7));
   printf("\n\n\nEnter the number of points you wish to calculate per cycle,\n");
   printf("(20000 maximum, program will use modulus if needed) :");
   scanf("%u",&counts);
   counts%=20001;
}  // end setparams

void sendtoport()
{
   int           i,temp;
   unsigned char lowbyte,hibyte;

   do
      {
      for( i = 0;i < counts;i++)
         {
         outport(Address+(dacnum*2),progstruct[i]);
         }
      }
   while (!kbhit());
   outport(Address+(dacnum*2),0);    // set DAC to 0 output
} // end sendtoport

void sinecurve()
{
   int             i;
   double          rads,sine;

   if (counts == 0) return;           // no point -- no curve

   clrscr();
   printf("Calculating sine wave points.....");

   rads = (double) 2 * PI / (counts - 1);   // rad per count

   for(i = 0;i < counts;i++)
      {
      sine = (sin(rads * i) + 1.0) * 2047;
      progstruct[i] = (unsigned) sine;
      }
   clrscr();
   printf("Generating sine wave, press any key to stop....");
   sendtoport();
} // end sinecurve

void trianglecurve(void)
{
   int             i;
   double          slope,temp;

   if (counts == 0) return;            // no counts -- no curve

   clrscr();
   printf("Calculating triangle wave points.....");

   slope = 4095.0 / counts * 2.0;
// wave form slope
   for(i=0;i < counts/2;i++)
      {
      temp = slope * i;
      progstruct[i] = (int)temp;
      temp = 4095 - temp;
      progstruct[i+counts/2+1] = (int)temp;
      }
   clrscr();
   printf("Generating triangle wave, press any key to stop....");
   sendtoport();
}  // end trianglecurve

void sawcurve()
{
   int             i;
   double          slope,temp;

   if (counts == 0) return;

   clrscr();
   printf("Calculating saw tooth wave points.....");

   slope = 4095.0 / counts;       /* saw tooth slope */

   for(i = 0;i < counts;i++)
      {
      temp = slope * i;
      progstruct[i] = (int) temp;
      progstruct[i] %= 4096;
      }
   clrscr();
   printf("Generating saw tooth wave, press any key to stop....");
   sendtoport();
} // end sawcurve

void menulist(void)
{
   clrscr();
   printf("\n\n\n");
   printf("Your menu selections are:\n");
   printf("1. Input Board Data  (do this first.)\n");
   printf("2. Sine curve\n");
   printf("3. Triangle curve\n");
   printf("4. Saw curve\n");
   printf("5. End program, return to DOS\n");
   printf("Input Choice: ");
}  // end menulist

/******************/
/*  main function */
/******************/
void main(void)
{
   char     menuchoice;

   clrscr();
   printf(
    "                        C SAMPLE #2: SAMPLE2.C                            \n"
    "                                                                         \n"
    "  This sample will generate 3 different wave forms, sine, triangle and   \n"
    "  saw tooth.  The user has the choice of base address, DAC number and the\n"
    "  number of points per cycle.                                            \n"
    "                                                                       \n\n"
    "  Board Configuration:                                                 \n\n"
    "  -- The Base Address should be set to the address which will be \n"
    "     entered during program execution\n"
    "\n\n\n\nPress any key to continue");
   getch();
   clrscr();

   do
      {
      memset(progstruct,0,sizeof(int));      // clear buffer
      menulist();                            // display the menu
      menuchoice=getch();                    // fetch the menu choice
      switch(menuchoice)                     // execute the menu selection
         {
         case '1': setparms();               // fetch the system params
                   outport(Address+0x04,0); // set DAC 0 to 0V output
                   outport(Address+0x06,0); // set DAC 1 to 0V output
                   outport(Address+0x08,0); // set DAC 2 to 0V output
                   outport(Address+0x0a,0); // set DAC 3 to 0V output
		   break;
         case '2': sinecurve();              // generate a sine wave
		   break;
         case '3': trianglecurve();          // generate a triangle wave
		   break;
         case '4': sawcurve();               // generate a saw tooth wave
		   break;
         case '5': ;                         // exit to operating system
         };
      }
   while(menuchoice !='5');
}  // end main