/* C9525 IS A FUCKING BAD INSTRUMENT - disgrace for Hamamatsu */

#include <stdio.h>   /* Standard input/output definitions    */
#include <stdlib.h>  /* Standard libraries definitions       */
#include <string.h>  /* String function definitions          */
#include <unistd.h>  /* UNIX standard function definitions   */
#include <fcntl.h>   /* File control definitions             */
#include <errno.h>   /* Error number definitions             */
#include <termios.h> /* POSIX terminal control definitions   */

#define Wsize 100     /* The longest string has 27 characters */

int fd;

int InitPort(void)
  {
    struct termios options;

    fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_NDELAY);

    if (fd == -1)
      {
        fputs("Unable to open port\n", stdout);
        return 0;
      }
    else
      {
        tcgetattr(fd, &options);

        cfsetispeed(&options, B9600);        /* Set the input  baud rate   */
        cfsetospeed(&options, B9600);        /* Set the output baud rate   */

        options.c_cflag |= (CLOCAL | CREAD); /* Enable receiver, set local */

        options.c_cflag &= ~PARENB;          /* Clear parity enable        */
        options.c_cflag &= ~CSTOPB;          /* Remove 2nd stop bit        */
        options.c_cflag &= ~CSIZE;           /* Clear data length          */
        options.c_cflag |= CS8;              /* Character size = 8 bits    */

        options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);  /* RAW input  */
        options.c_oflag &= ~OPOST;                           /* RAW output */

        options.c_cflag &= ~CRTSCTS;      /* Disable hardware flow control */

        tcsetattr(fd, TCSAFLUSH, &options);  /* clear buffers */

        tcsetattr(fd, TCSANOW, &options);    /* set attributes immediately */
        return 1;
      }
  }


int WritePort(char Command[], int Length)
  {
    char *BufPtr;
    int i;

    BufPtr = Command;

    for (i=0; i<Length; i++)
      {
        usleep(2000);
        write(fd, BufPtr, 1);
        BufPtr++;
      }

    return 1;
  }


char *sgets(char *line, size_t size)
{
   size_t i;
   for ( i = 0; i < size - 1; ++i )
   {
      int ch = fgetc(stdin);
      if ( ch == '\n' || ch == EOF )
      {
         break;
      }
      line[i] = ch;
   }
   line[i] = '\0';
   return line;
}


int main(void)
{
  const char delimiters[] = " ,;\t";
        char Command[4], Buffer[Wsize];
  unsigned Value20, Value99;
  int Chan, Vset, Ramp, Step, Vnew, Sign;
  int i, k, numBytes;

/* sleep = safety * (1M [us] / 9600 baud) * N words * 10 bit / 9600 baud */
  int Latency = 10 * (1000000/10000) * Wsize * 10;

  if (!InitPort()) return 0;

/* set device to remote control */
  printf("Set remote control\n");

  Command[0] = 'Q';
  Command[1] = 0x01;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

/* wait for response */
  usleep(Latency);

  for(i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

/* device output on */
  printf("Output ON\n");

  Command[0] = 'O';
  Command[1] = 0x01;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);


while (1) {

/* read input parameters */
       char Text[11] = "";
       char *TPtr, *token;

       fputs("Enter Ch# U(V) Ramp(V/s): ", stdout);
       fflush(stdout);
       sgets(Text, sizeof Text);
       TPtr = Text;

       token = strsep(&TPtr, delimiters);
       Chan  = atoi(token);

       token = strsep(&TPtr, delimiters);
       Vset  = atoi(token);       

       token = strsep(&TPtr, delimiters);
       Ramp  = atoi(token);

       if (Chan != 1) break;
       if (Ramp == 0) break;

/* Ground Zero */

/* set device to remote control */
//  printf("Set remote control\n");
  Command[0] = 'Q';
  Command[1] = 0x01;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

/* read voltage */
//  printf("read voltage\n");
  Command[0] = 'T';
  Command[1] = '\r';
  Command[2] = 0x00;
  Command[3] = 0x00;
  WritePort(Command, 2);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);





/* Donkey Job */

  Vnew = Buffer[0]*100 + Buffer[1];
  Step = abs(Vset - Vnew) / Ramp;

  if (Vset > Vnew) Sign =  1;
  if (Vset < Vnew) Sign = -1;

  printf("initial setting %d, steps %d, speed %d\n", Vnew, Sign*Step, Ramp);

  for (k=0; k<Step; k++)
     {
        Vnew = Vnew + Sign * Ramp;

/* set device to remote control */
//        printf("Set remote control\n");
        Command[0] = 'Q';
        Command[1] = 0x01;
        Command[2] = '\r';
        Command[3] = 0x00;
        WritePort(Command, 3);

/* wait for response */
        usleep(Latency);

        for (i=0; i<Wsize; i++) Buffer[i]=0x00;
        numBytes = read(fd, &Buffer, Wsize);
//        printf("return bytes %d status %s\n", numBytes, Buffer);

/* set voltage */
        printf("set step %d ", Vnew);

        Value20 = (unsigned) Vnew / 100;
        Value99 = (unsigned) Vnew % 100;

        Command[0] = 'V';
        Command[1] = Value20;
        Command[2] = Value99;
        Command[3] = '\r';
        WritePort(Command, 4);

/* wait for response */
        usleep(Latency);

        for (i=0; i<Wsize; i++) Buffer[i]=0x00;
        numBytes = read(fd, &Buffer, Wsize);
//        printf("return bytes %d status %s\n", numBytes, Buffer);

/* set device to remote control */
//        printf("Set remote control\n");
        Command[0] = 'Q';
        Command[1] = 0x01;
        Command[2] = '\r';
        Command[3] = 0x00;
        WritePort(Command, 3);

/* wait for response */
        usleep(Latency);

        for (i=0; i<Wsize; i++) Buffer[i]=0x00;
        numBytes = read(fd, &Buffer, Wsize);
//        printf("return bytes %d status %s\n", numBytes, Buffer);

/* read voltage */
//        printf("read voltage\n");
        Command[0] = 'T';
        Command[1] = '\r';
        Command[2] = 0x00;
        Command[3] = 0x00;
        WritePort(Command, 2);

/* wait for response */
        usleep(Latency);

        for (i=0; i<Wsize; i++) Buffer[i]=0x00;
        numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

        printf(" // get step %d\n", Buffer[0]*100 + Buffer[1]);

/* ramp speed timer */
        usleep(1000000);
     } /* for k<Steps */


/* Round Up */

/* set device to remote control */
//  printf("Set remote control\n");
  Command[0] = 'Q';
  Command[1] = 0x01;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

/* set final voltage */
  printf("set destination voltage %d", Vset);

  Value20 = (unsigned) Vset / 100;
  Value99 = (unsigned) Vset % 100;

  Command[0] = 'V';
  Command[1] = Value20;
  Command[2] = Value99;
  Command[3] = '\r';
  WritePort(Command, 4);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

/* set device to remote control */
//  printf("Set remote control\n");
  Command[0] = 'Q';
  Command[1] = 0x01;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

/* read voltage */
//  printf("read voltage\n");
  Command[0] = 'T';
  Command[1] = '\r';
  Command[2] = 0x00;
  Command[3] = 0x00;
  WritePort(Command, 2);

/* wait for response */
  usleep(Latency);

  for (i=0; i<Wsize; i++) Buffer[i]=0x00;
  numBytes = read(fd, &Buffer, Wsize);
//  printf("return bytes %d status %s\n", numBytes, Buffer);

  printf(" // get voltage %d\n", Buffer[0]*100 + Buffer[1]);


}; /* while (1) */

/* set device to local control */
  printf("back to local control, bye !\n ");
  Command[0] = 'Q';
  Command[1] = 0x00;
  Command[2] = '\r';
  Command[3] = 0x00;
  WritePort(Command, 3);

  close(fd);
  return 1;
}