#include <16F876.h>
#use delay(clock=6000000)
#fuses HS,NOWDT,PUT,NOBROWNOUT,NOLVP
#use rs232(baud=1200,parity=N,xmit=PIN_C6,rcv=PIN_C7)


#byte porta = 5
#byte portb = 6
#byte portc = 7

#bit  head_1 = portb.0
#bit  head_2 = portb.1
#bit  head_3 = portb.2
#bit  head_4 = portb.3
#bit  head_5 = portb.4
#bit  head_6 = portb.5
#bit  head_7 = portb.6
#bit  head_8 = portb.7

#bit  motor_1 = porta.0
#bit  motor_2 = porta.1
#bit  motor_3 = porta.2
#bit  motor_4 = porta.3

#bit  home_pos = porta.4

#define  at_home  !home_pos

#define  ESCAPE               0x1B
#define  CR                   0x0D

#define HEAD_RANK_A_TIMING    1265
#define HEAD_RANK_B_TIMING    1156
#define HEAD_RANK_C_TIMING    1047

#define  HEAD_TIMING             HEAD_RANK_B_TIMING
#define  HEAD_TIMING_70_PERCENT  ((HEAD_TIMING * 700) / 1000)
#define  HEAD_TIMING_90_PERCENT  ((HEAD_TIMING * 900) / 1000)

#define  MOTOR_TIMING         5
#define  PAPER_BEGINING       40
#define  LINE_FEED_COUNT      168

enum
{
   ASCII_BLOCK_1 = 1,
   ASCII_BLOCK_2,
   ASCII_BLOCK_3
};

char phase_state,head_pos,in_ptr,out_ptr,rx_blk[70];
short escape_set;

char const ascii1[32][7] =
{
   { 0x00,0x00,0x00,0x00,0x00,0x00,0x00 },   //
   { 0x40,0x40,0x40,0x40,0x00,0x00,0x40 },   // !
   { 0x50,0x50,0x50,0x00,0x00,0x00,0x00 },   // "
   { 0x50,0x50,0xF8,0x50,0xF8,0x50,0x50 },   // #
   { 0x40,0x78,0xA0,0x70,0x28,0xF0,0x20 },   // $
   { 0xC0,0xC8,0x10,0x20,0x40,0x98,0x18 },   // %
   { 0x60,0x90,0xA0,0x40,0xA0,0x90,0x68 },   // &
   { 0x60,0x20,0x40,0x00,0x00,0x00,0x00 },   // '
   { 0x10,0x20,0x40,0x40,0x40,0x20,0x10 },   // (
   { 0x40,0x20,0x10,0x10,0x10,0x20,0x40 },   // )
   { 0x00,0x20,0xA8,0x70,0xA8,0x20,0x00 },   // *
   { 0x00,0x20,0x20,0xF8,0x20,0x20,0x00 },   // +
   { 0x00,0x00,0x00,0x00,0x60,0x20,0x40 },   // ,
   { 0x00,0x00,0x00,0xF8,0x00,0x00,0x00 },   // -
   { 0x00,0x00,0x00,0x00,0x00,0x30,0x30 },   // .
   { 0x08,0x10,0x20,0x40,0x80,0x00,0x00 },   // /
   { 0x70,0x88,0x98,0xA8,0xC8,0x88,0x70 },   // 0
   { 0x20,0x60,0x20,0x20,0x20,0x20,0x70 },   // 1
   { 0x70,0x88,0x08,0x10,0x20,0x40,0xF8 },   // 2
   { 0xF8,0x10,0x20,0x10,0x08,0x88,0x70 },   // 3
   { 0x10,0x30,0x50,0x90,0xF8,0x10,0x10 },   // 4
   { 0xF8,0x80,0xF0,0x08,0x08,0x88,0x70 },   // 5
   { 0x30,0x40,0x80,0xF0,0x88,0x88,0x70 },   // 6
   { 0xF8,0x08,0x10,0x20,0x40,0x40,0x40 },   // 7
   { 0x70,0x88,0x88,0x70,0x88,0x88,0x70 },   // 8
   { 0x70,0x88,0x88,0x78,0x08,0x10,0x60 },   // 9
   { 0x00,0x30,0x30,0x00,0x30,0x30,0x00 },   // :
   { 0x00,0x30,0x30,0x00,0x30,0x10,0x20 },   // ;
   { 0x08,0x10,0x20,0x40,0x20,0x10,0x08 },   // <
   { 0x00,0x00,0xF8,0x00,0xF8,0x00,0x00 },   // =
   { 0x40,0x20,0x10,0x08,0x10,0x20,0x40 },   // >
   { 0x70,0x88,0x08,0x10,0x20,0x00,0x20 }   // ?
};

char const ascii2[32][7] =
{
   { 0x70,0x88,0x08,0x68,0xA8,0xA8,0x70 },   // @
   { 0x70,0x88,0x88,0x88,0xF8,0x88,0x88 },   // A
   { 0xF0,0x88,0x88,0xF0,0x88,0x88,0xF0 },   // B
   { 0x70,0x88,0x80,0x80,0x80,0x88,0x70 },   // C
   { 0xE0,0x90,0x88,0x88,0x88,0x90,0xE0 },   // D
   { 0xF8,0x80,0x80,0xF0,0x80,0x80,0xF8 },   // E
   { 0xF8,0x80,0x80,0xF0,0x80,0x80,0x80 },   // F
   { 0x70,0x88,0x80,0xB8,0x88,0x88,0x78 },   // G
   { 0x88,0x88,0x88,0xF8,0x88,0x88,0x88 },   // H
   { 0x70,0x20,0x20,0x20,0x20,0x20,0x70 },   // I
   { 0x38,0x10,0x10,0x10,0x10,0x90,0x60 },   // J
   { 0x88,0x90,0xA0,0xC0,0xA0,0x90,0x88 },   // K
   { 0x80,0x80,0x80,0x80,0x80,0x80,0xF8 },   // L
   { 0x88,0xD8,0xA8,0xA8,0x88,0x88,0x88 },   // M
   { 0x88,0x88,0xC8,0xA8,0x98,0x88,0x88 },   // N
   { 0x70,0x88,0x88,0x88,0x88,0x88,0x70 },   // O
   { 0xF0,0x88,0x88,0xF8,0x80,0x80,0x80 },   // P
   { 0x70,0x88,0x88,0x88,0xA8,0x98,0x68 },   // Q
   { 0xF0,0x88,0x88,0xF0,0xA0,0x90,0x88 },   // R
   { 0x78,0x80,0x80,0x70,0x08,0x08,0xF0 },   // S
   { 0xF8,0x20,0x20,0x20,0x20,0x20,0x20 },   // T
   { 0x88,0x88,0x88,0x88,0x88,0x88,0x70 },   // U
   { 0x88,0x88,0x88,0x88,0x88,0x50,0x20 },   // V
   { 0x88,0x88,0x88,0xA8,0xA8,0xA8,0x50 },   // W
   { 0x88,0x88,0x50,0x20,0x50,0x88,0x88 },   // X
   { 0x88,0x88,0x88,0x50,0x20,0x20,0x20 },   // Y
   { 0xF8,0x08,0x10,0x20,0x40,0x80,0xF8 },   // Z
   { 0x70,0x40,0x40,0x40,0x40,0x40,0x70 },   // [
   { 0x00,0x00,0x00,0x00,0x00,0x00,0x00 },   //
   { 0x70,0x10,0x10,0x10,0x10,0x10,0x70 },   // ]
   { 0x20,0x50,0x88,0x00,0x00,0x00,0x00 },   // ^
   { 0x00,0x00,0x00,0x00,0x00,0x00,0xF8 }    // _
};

char const ascii3[32][7] =
{
   { 0x40,0x20,0x10,0x00,0x00,0x00,0x00 },   // '
   { 0x00,0x00,0x70,0x08,0x78,0x88,0x78 },   // a
   { 0x80,0x80,0xB0,0xC8,0x88,0x88,0xF0 },   // b
   { 0x00,0x00,0x70,0x80,0x80,0x88,0x70 },   // c
   { 0x08,0x08,0x68,0x98,0x88,0x88,0x78 },   // d
   { 0x00,0x00,0x70,0x88,0xF8,0x80,0x70 },   // e
   { 0x30,0x48,0x40,0xE0,0x40,0x40,0x40 },   // f
   { 0x00,0x78,0x88,0x88,0x78,0x08,0x70 },   // g
   { 0x80,0x80,0xB0,0xC8,0x88,0x88,0x88 },   // h
   { 0x20,0x00,0x60,0x20,0x20,0x20,0x70 },   // i
   { 0x10,0x00,0x30,0x10,0x10,0x90,0x60 },   // j
   { 0x40,0x40,0x48,0x50,0x60,0x50,0x48 },   // k
   { 0x60,0x20,0x20,0x20,0x20,0x20,0x70 },   // l
   { 0x00,0x00,0xD0,0xA8,0xA8,0x88,0x88 },   // m
   { 0x00,0x00,0xB0,0xC8,0x88,0x88,0x88 },   // n
   { 0x00,0x00,0x70,0x88,0x88,0x88,0x70 },   // o
   { 0x00,0x00,0xF0,0x88,0xF0,0x80,0x80 },   // p
   { 0x00,0x00,0x68,0x98,0x78,0x08,0x08 },   // q
   { 0x00,0x00,0xB0,0xC8,0x80,0x80,0x80 },   // r
   { 0x00,0x00,0x70,0x80,0x70,0x08,0xF0 },   // s
   { 0x40,0x40,0xE0,0x40,0x40,0x48,0x30 },   // t
   { 0x00,0x00,0x88,0x88,0x88,0x98,0x68 },   // u
   { 0x00,0x00,0x88,0x88,0x88,0x50,0x20 },   // v
   { 0x00,0x00,0x88,0x88,0xA8,0xA8,0x50 },   // w
   { 0x00,0x00,0x88,0x50,0x20,0x50,0x88 },   // x
   { 0x00,0x00,0x88,0x88,0x78,0x08,0x70 },   // y
   { 0x00,0x00,0xF8,0x10,0x20,0x40,0xF8 },   // z
   { 0x10,0x20,0x20,0x40,0x20,0x20,0x10 },   // {
   { 0x20,0x20,0x20,0x20,0x20,0x20,0x20 },   // |
   { 0x40,0x20,0x20,0x10,0x20,0x20,0x40 },   // }
   { 0x00,0x40,0x20,0xF8,0x20,0x40,0x00 },   // ->
   { 0x00,0x20,0x40,0xF8,0x40,0x20,0x00 }    // <-
};

// ********************************************************************

#int_rda
rda_isr()
{
   rx_blk[in_ptr++] = getchar();
   if(in_ptr >= sizeof(rx_blk))
      in_ptr = 0;
}

// ********************************************************************

char get_char(void)
{
   char ret_val;

   while(in_ptr == out_ptr)
      ;

   ret_val = rx_blk[out_ptr++];

   if(out_ptr >= sizeof(rx_blk))
      out_ptr = 0;
      
   return(ret_val);      
}

// ********************************************************************

void clear_buffer(void)
{
   in_ptr = out_ptr = 0;
}

// ********************************************************************

void head_forward(char count)
{
   char i;

   if(!count)
      return;

   for(i=0;i<count;i++)
   {
      switch(phase_state)
      {
         case 0:
         {
            motor_1 = motor_2 = FALSE;
            motor_3 = motor_4 = TRUE;
         }
         break;

         case 1:
         {
            motor_1 = motor_4 = FALSE;
            motor_2 = motor_3 = TRUE;
         }
         break;

         case 2:
         {
            motor_3 = motor_4 = FALSE;
            motor_1 = motor_2 = TRUE;
         }
         break;

         case 3:
         {
            motor_3 = motor_2 = FALSE;
            motor_1 = motor_4 = TRUE;
         }
         break;
      }
      delay_ms(MOTOR_TIMING);

      if(++phase_state == 4)
         phase_state = 0;

      head_pos++;
   }


   motor_1 = motor_2 = motor_3 = motor_4 = FALSE;
}

// ********************************************************************

void head_backward(char count)
{
   char i;

   if(!count)
      return;

   for(i=0;i<count;i++)
   {
      switch(phase_state)
      {
         case 0:
         {
            motor_1 = motor_4 = FALSE;
            motor_3 = motor_2 = TRUE;
         }
         break;

         case 1:
         {
            motor_1 = motor_2 = FALSE;
            motor_4 = motor_3 = TRUE;
         }
         break;

         case 2:
         {
            motor_3 = motor_2 = FALSE;
            motor_1 = motor_4 = TRUE;
         }
         break;

         case 3:
         {
            motor_3 = motor_4 = FALSE;
            motor_1 = motor_2 = TRUE;
         }
         break;
      }

      delay_ms(MOTOR_TIMING);

      if(++phase_state == 4)
         phase_state = 0;

      head_pos--;
   }

   motor_1 = motor_2 = motor_3 = motor_4 = FALSE;
}

// ********************************************************************

void return_home(void)
{
   while(!at_home)
      head_backward(1);

   delay_ms(750);
   head_pos = 0;
   head_forward(PAPER_BEGINING);
}

// ********************************************************************

void print_pixel_line(char line)
{
   char i,j,ratio;
   short current_bit;

   portb = line;
   delay_ms(12);
   portb = 0;
   head_forward(1);
}

// ********************************************************************

void  print_char(char ch)
{
   char i,type,ent,y,m,ptr;

   type = 0;

   if((ch < ' ') || (ch > 0x7F))
      return(FALSE);

   if(ch <= '?')
   {
      type = ASCII_BLOCK_1;
      ent = ch - 0x20;
   }

   if((ch >= '@') && (ch <= '_'))
   {
      type = ASCII_BLOCK_2;
      ent = ch - 0x40;
   }

   if(!type)
   {
      type = ASCII_BLOCK_3;
      ent = ch - 0x60;
   }
//printf("\r\nCh = %c,Type = %02X, Ent = %02X",ch,type,ent);
   ptr = 0x80;
   for(i=0;i<7;i++)
   {
      m = 0;

      for(y=0;y<7;y++)
      {
         switch(type)
         {
            case ASCII_BLOCK_1:
            {
               if(ascii1[ent][y] & ptr)
                  bit_set(m,y);
            }
            break;

            case ASCII_BLOCK_2:
            {
               if(ascii2[ent][y] & ptr)
                  bit_set(m,y);
            }
            break;

            case ASCII_BLOCK_3:
            {
               if(ascii3[ent][y] & ptr)
                  bit_set(m,y);
            }
            break;
         }
      }
      ptr >>= 1;
//printf(" [%02X,%02X-%02X]",i,y,m);
      print_pixel_line(m);
   }
   head_forward(1);
}

// *******************************************************************

void line_feed(void)
{
   if(head_pos < LINE_FEED_COUNT)
   {
      if(!at_home)
         return_home();

      head_forward(LINE_FEED_COUNT);
   }
   return_home();
}

// *******************************************************************

char get_nibble(void)
{
   char dat;

   escape_set = FALSE;

   dat = getc();
   if(dat == ESCAPE)
   {
      escape_set = TRUE;
      return(0);
   }

//   putchar(dat);

   if(dat < 'A')
      dat &= 0x0F;
   else
      dat = ((dat & 0xDF) - 'A') + 0x0A;

   return(dat);
}

// *******************************************************************

char get_byte(void)
{
   char dat,dat1;

   dat = (get_nibble() << 4);

   if(escape_set)
      return(0);

    dat1 = get_nibble();

   if(escape_set)
      return(0);

   return(dat + dat1);
}

// ********************************************************************

void debug(void)
{
   char i;
         
   while(TRUE)
   {
      escape_set = FALSE;
      printf("\r\n\r\n(R)eturn Home,(F)orward,(B)ackward,(P)ixel Line,(C)hars\r\n");
      printf("Paper (L)oad,Line F(E)ed,(N)umbers,(T)est");
      putchar(' ');
      i = toupper(get_char());
      printf("\r\n");

      switch(i)
      {
         case 'T':
         {
//            printf("Time :- %02X. New :- ",step_time);
//            step_time = get_byte();
//            printf("\r\nNew  :- %02x",step_time);
            while(TRUE)
            {
               return_home();
               for(i='A';i<= 'Z';i++)
                  print_char(i);
               for(i='0';i<= '?';i++)
                  print_char(i);
               if(in_ptr != out_ptr)
                  break;
            }
            clear_buffer();
         }
         break;

         case 'C':
         {
            while(!escape_set)
            {
               i = get_char();

               if(i == CR)
               {
                  printf("\r\n%u\r\n",head_pos);
                  return_home();
                  continue;
               }
               
               if(i == ESCAPE)
               {
                  clear_buffer();
                  break;
               }
               print_char(i);
            }
         }
         break;

         case 'R':
         {
            return_home();
         }
         break;

         case 'N':
         {
            i = 0;
            do
            {
               print_pixel_line(i);
               printf("\r\n%u ",i);
            }
            while(++i);
         }
         break;

         case 'E':
         {
            line_feed();
         }
         break;

         case 'L':
         {
            for(i=0;i<5;i++)
               line_feed();
         }
         break;

         case 'F':
         {
            head_forward(1);
         }
         break;

         case 'B':
         {
            head_backward(1);
         }
         break;

         case 'P':
         {
            while(TRUE)
            {
               i = get_byte();
               putchar(' ');
               if(escape_set)
                  break;
               print_pixel_line(i);
            }
         }
         break;
      }
   }
}

// ********************************************************************

void main()
{
   char i;

   setup_adc_ports(NO_ANALOGS);
   setup_adc(ADC_CLOCK_DIV_2);
   setup_spi(FALSE);
   setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
   setup_timer_1(T1_DISABLED);
   setup_timer_2(T2_DISABLED,0,1);
   setup_ccp1(CCP_OFF);
   setup_ccp2(CCP_OFF);

   set_tris_a(0x10);
   set_tris_b(0x00);
   set_tris_c(0x80);

   porta = 0;
   portb = 0;
   portc = 0;
   motor_1 = motor_2 = motor_3 = motor_4 = FALSE;

   escape_set = FALSE;
   phase_state = 0;

   in_ptr = out_ptr = 0;

   delay_ms(2000);
   line_feed();

   enable_interrupts(INT_RDA);
   enable_interrupts(GLOBAL);

   if(get_char() == '*')   // Do debug
      debug();
      
   while(TRUE)
   {
      i = get_char();
      
      if(i < CR)
         continue;

      if(i == CR)
      {
         line_feed();
         continue;
      }
               
      if(i == ESCAPE)
      {
         clear_buffer();
         continue;
      }
      print_char(i);
   }
}