Scroll text on 7seg. digits with PMP

program scroll7seg;

{$PROCESSOR PIC18f2550}

{$FREQUENCY 48 MHZ}

{$OPTIMIZE MEMORY}

{$VECTORS RESET = $800, INT_HIGH = $808, INT_LOW = $818}

{$CONFIG OFF}

uses seven_segment, 

tmr0_isr_interval;

const

  text_string: array[0..23] of byte = (// --27 is "Space" character

    27,27,27,23,10,16,12,10,21,27,    //--    PASCAL

    15,22,18,27,                      //-- For

    4,22,26,18,27,                    //-- Your

    26,12,27,27,27                    //-- uC

  ); 

  leds_sequence: array[0..30] of byte = (

    0,1,3,7,15,31,63,127,255,254,252,248,240,224,192,128,0,// complete sequence

    128,192,224,240,248,252,255,127,63,31,15,7,3,1); //and reverse

var

  digits_buffer:array[0..3] of byte;

  //-- indices

  ix_text,ix_led: byte;

procedure PORTTEXT(x:byte); //7segments port: RB0 is segment a

begin                       // Dot segment is not connected

  LATB.0 := x.0;  //seg a

  LATB.1 := x.1;  //seg b

  LATB.2 := x.2;  //seg c

  LATB.3 := x.3;  //seg d

  LATB.4 := x.4;  //seg e

  LATB.5 := x.5;  //seg f

  LATB.6 := x.6;  //seg g

end;

procedure portA_low(x:byte);  //select digits

begin

  LATA.0 := x.0; // select digit nr.4 on EvB4.3 board

  LATA.1 := x.1; // select digit nr.3

  LATA.2 := x.2; // select digit nr.2

  LATA.3 := x.3; // select digit nr.1

end;

procedure show_digits;

begin

  PORTTEXT(seven_from_digit(27));

  portA_low(7);// -- 0b0111, digits are selectable with a 0 logic on my board

  PORTTEXT(digits_buffer[3]);

  delay(1500);

  //--

  PORTTEXT(seven_from_digit(27));

  portA_low(11); //-- 0b1011

  PORTTEXT(digits_buffer[2]);

  delay(1500);

  //--

  PORTTEXT(seven_from_digit(27));

  portA_low(13);// -- 0b1101

  PORTTEXT(digits_buffer[1]);

  delay(1500);

  //--

  PORTTEXT(seven_from_digit(27));

  portA_low(14); //-- 0b1110

  PORTTEXT(digits_buffer[0]);

  delay(1500);

  //--

end;

procedure update_buffer(id: byte);

begin

  digits_buffer[3] := seven_from_digit(text_string[id]);

  digits_buffer[2] := seven_from_digit(text_string[id + 1]);

  digits_buffer[1] := seven_from_digit(text_string[id + 2]);

  digits_buffer[0] := seven_from_digit(text_string[id + 3]);

end;

procedure PORTLED(x:byte);

begin             //FreeJALduino pinout

  LATC.7 := x.0;  //D0  LED nr.1

  LATC.6 := x.1;  //D1  LED nr.2

  LATA.4 := x.2;  //D2  LED nr.3

  LATB.7 := x.3;  //D10 LED nr.4

  LATC.0 := x.4;  //D11 LED nr.5

  LATC.1 := x.5;  //D12 LED nr.6

  LATC.2 := x.6;  //D13 LED nr.7

  LATA.5 := x.7;  //D18 LED nr.8

end;

//-------- START -------------

begin

  //-- Initializations

  TRISA := 0; // as output

  TRISB := 0;

  TRISC := 0;

  //adc_off

  ADCON0 := 0b00000000; // -- disable ADC

  ADCON1 := 0b00001111; // -- digital I/O

  ADCON2 := 0b00000000; //

  //comparator_off

  CMCON  := 0b00000111; // -- disable comparator

  //-- digits OFF

  portA_low(0b1111);

  timer0_isr_init; // -- init timer0 isr

  //-- init index

  ix_text := 0;

  ix_led  := 0;

  //-- fill the digits buffer

  update_buffer(ix_text);

  //-- start LED sequence

  PORTLED(leds_sequence[ix_led]);

  //-- set scroll speed for text

  set_delay(0, 300);

  //-- set scroll speed for LED's

  set_delay(1, 100);

  loop // instead of "while(1) do begin" - new feature ;)

    show_digits;

    if check_delay(0) then begin

      ix_text := ix_text + 1;

      if ix_text = 21 then 

        ix_text := 0;

      update_buffer(ix_text);

      set_delay(0, 300);

    end;

    if check_delay(1) then begin

      ix_led := ix_led + 1;

      if ix_led = 31 then 

        ix_led := 0;

      PORTLED(leds_sequence[ix_led]);

      set_delay(1, 100)

    end;

  end; //loop

end.