' ----------------------------------------------------
' LCDShield library
' ----------------------------------------------------

' ----------------------------------------------------
' Backlight on/off
' 0 = off, 1 = on
' ----------------------------------------------------
SUB LCDShield_Backlight ( LCDShield_blstate )
' pin = 31
SETPIN 31, 8
PIN(31) = LCDShield_blstate
END SUB


' ----------------------------------------------------
' Write 4-bit command
' ----------------------------------------------------
SUB LCDShield_Command4( LCDShield_value )

' Data lines
SETPIN 25, 8 : SETPIN 26, 8 : SETPIN 27, 8 : SETPIN 28, 8

' Register Select line
SETPIN 29, 8

' Enable line
SETPIN 30, 8

' Command
PIN(29) = 0

' Enable high
PIN(30) = 1 : PAUSE 1

' Value onto data lines
PIN(28) = LCDShield_value AND &B00001000
PIN(27) = LCDShield_value AND &B00000100
PIN(26) = LCDShield_value AND &B00000010
PIN(25) = LCDShield_value AND &B00000001

' Enable low then high
PIN(30) = 0 : PAUSE 1
PIN(30) = 1 : PAUSE 1

END SUB


' ----------------------------------------------------
' Write 8-bit character
' ----------------------------------------------------
SUB LCDShield_Character( LCDShield_value )

' Character
PIN(29) = 1

' Enable high
PIN(30) = 1 : PAUSE 1

' Value (high nibble) onto data lines
PIN(28) = LCDShield_value AND &B10000000
PIN(27) = LCDShield_value AND &B01000000
PIN(26) = LCDShield_value AND &B00100000
PIN(25) = LCDShield_value AND &B00010000

' Enable low then high
PIN(30) = 0 : PAUSE 1
PIN(30) = 1 : PAUSE 1

' Value (low nibble) onto data lines
PIN(28) = LCDShield_value AND &B00001000
PIN(27) = LCDShield_value AND &B00000100
PIN(26) = LCDShield_value AND &B00000010
PIN(25) = LCDShield_value AND &B00000001

' Enable low then high
PIN(30) = 0 : PAUSE 1
PIN(30) = 1 : PAUSE 1

END SUB


' ----------------------------------------------------
' Write string
' ----------------------------------------------------
SUB LCDShield_String( LCDShield_string$ )
FOR LCDShield_loop = 1 to LEN(LCDShield_string$)
LCDShield_Character( ASC(MID$(LCDShield_string$, LCDShield_loop )))
NEXT
END SUB


' ----------------------------------------------------
' Return button state
' 0 = no button
' 1 = right, 2 = up, 3 = down, 4 = left
' Because A/D on CGCOLORMAX is 3.3V max and this is a
' 5V resistor chain the SEL button does not work.
' ----------------------------------------------------
FUNCTION LCDShield_Button( )
' Button Input line
SETPIN 35, 1
LCDShield_Button = 0
IF PIN(35) < 2.85 THEN
LCDShield_Button = 4
ENDIF
IF PIN(35) < 1.95 THEN
LCDShield_Button = 3
ENDIF
IF PIN(35) < 1.1 THEN
LCDShield_Button = 2
ENDIF
IF PIN(35) < .32 THEN
LCDShield_Button = 1
ENDIF
END FUNCTION

' ====================================================
'
' LCDShield example
'
' ====================================================

' Flash display
for a = 1 to 5
LCDShield_Backlight( 0 ) : PAUSE 40
LCDShield_Backlight( 1 ) : PAUSE 60
next a

' Initialize display
' Select 4 bit mode
LCDShield_Command4(&H03)
LCDShield_Command4(&H03)
LCDShield_Command4(&H03)
LCDShield_Command4(&H02)

' Select 4 bit mode, two LCD lines
LCDShield_Command4(&H02)
LCDShield_Command4(&H0C)

' Select display on, cursor off, no blink
LCDShield_Command4(&H00)
LCDShield_Command4(&H0C)

' Clear display
LCDShield_Command4(&H00)
LCDShield_Command4(&H01)


' Write Hi Mom! message to line 1
LCDShield_Character(72)
LCDShield_Character(73)

LCDShield_Character(32)

LCDShield_Character(77)
LCDShield_Character(111)
LCDShield_Character(109)

LCDShield_Character(33)

PAUSE 1000

' Clear display
LCDShield_Command4(&H00)
LCDShield_Command4(&H01)

' Write message to line 1
LCDShield_String ( "CircuitGizmos" )

' Move to line 2
LCDShield_Command4(&H0C)
LCDShield_Command4(&H00)

' Write message to line 2
LCDShield_String ( "Rules!" )

' Test buttons
for a = 1 to 500
PRINT LCDShield_Button()
PAUSE 1000
next a