' =========================================================================
' File...... Crude timer.BS2
' Purpose... Parallel LCD timer
' Author.... Mike Seiler
' E-mail.... ms767210@bigpond.net.au
' {$STAMP BS2}

' -----[ I/O Definitions ]-------------------------------------------------
E CON 6 ' Enable Pin For LCD
RW CON 5 ' R/W Pin For LCD
RS CON 4 ' LCD Register Select  0 = Instruction, 1 = Text
' -----[ Variables ]-------------------------------------------------------
    char VAR Byte         ' Character To Send To LCD
    Index VAR Byte        ' Character pointer
    cursor_pos VAR Byte
    period VAR Bit
    second VAR Byte
    minute VAR Byte
    hour VAR Byte
    minute_tens VAR Nib
    hour_tens VAR Nib

' -----[ Constants ]-------------------------------------------------------
    Clr_Display CON %00000001     ' Clear the display
    EntryMode_Set CON %00000111
    Display_Off CON %00001000     ' Turn display off
    Display_On CON %00001100     ' Turn display on set cursor on
    Modeset CON %00111000        ' Set 8 bit mode 2 lines and 5x7 characters
' Initialise I/O ----------------------------------------------------------
    DIRB = %1110
    OUTB = %0000
    DIRH = %11111111
    OUTH = %00000000
' Message to send
    Msg DATA "11:00am"

Main:
    PAUSE 150             'delay till power reaches desired level on powerup
    char = Modeset
    GOSUB lcdcmd
    char = Display_Off
    GOSUB LCDcmd
    char = Display_On
    GOSUB LCDcmd
    char = Clr_Display
    GOSUB LCDcmd
    GOSUB start
    OUTS = %0000000000000000
    HIGH RS
    char = 0
    GOTO Seconds


LCDcmd:
    OUTH = char
    LOW RS
    PULSOUT E, 1
    RETURN

LCDwr:
    OUTH = char
    HIGH RS
    PULSOUT E, 1
    RETURN

Start:
    FOR index = 0 TO 6
    READ msg + index, char
      GOSUB LCDwr
    NEXT
    RETURN

Seconds:
    FOR second = 1 TO 60
    PAUSE 999
    NEXT

Minutes:
    minute = minute + 1
    IF minute = 10 THEN tens_minutes
    char = minute
    cursor_pos = 132
    GOSUB Update_display
    GOTO seconds

tens_minutes:
    minute_tens = minute_tens + 1
    IF minute_tens = 6 THEN hours
    char = minute_tens
    cursor_pos = 131
    GOSUB Update_display
    RETURN

hours:
    hour = hour + 1
    IF hour = 13 THEN finish
    char = hour
    cursor_pos = 129
    GOSUB Update_display
    RETURN

Update_display:
    OUTH = cursor_pos
    LOW rs
    PULSOUT e, 1
    OUTH = char + 48
    HIGH rs
    PULSOUT e, 1
    RETURN

finish:
    END
    END

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