{ Copyright (C)2026, Philip Munts dba Munts Technologies.                     }
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PROGRAM UnipolarStepperDriverFull;

CONST
  FullStep : ARRAY [0 .. 3] OF byte = ($09, $0C, $06, $03);

VAR
  Dir  : SBIT AT PINB.B5;
  Step : SBIT AT PINB.B4;

  OutputIndex : Byte;
  OldState    : Boolean;
  NewState    : Boolean;

BEGIN
  PORTB       := $00;
  DDRB        := $0F;
  OutputIndex := 0;
  PORTB       := FullStep[OutputIndex];
  OldState    := Step;

  REPEAT
    NewState := Step;

    IF NewState AND NOT OldState THEN
      BEGIN
        IF Dir THEN
          OutputIndex := (OutputIndex + 1) AND $03
        ELSE
          OutputIndex := (OutputIndex - 1) AND $03;

        PORTB := FullStep[OutputIndex];
      END;

    OldState := NewState;
  UNTIL False;
END.