' A PID controller using the Hitachi HD44780 LCD controller chip in 4-bit mode

' 4-button interface
Const INPUT_MODE As Byte = 5 'to Pin 5
Const INPUT_UP As Byte = 6 'to Pin 6
Const INPUT_DOWN As Byte = 7 'to Pin 7
Const INPUT_COMMIT As Byte = 8 'to Pin 8

' HD44780 4-bit Data lines
Const HD44780_DB3 As Byte = 9  'Most significant bit
Const HD44780_DB2 As Byte = 10
Const HD44780_DB1 As Byte = 11
Const HD44780_DB0 As Byte = 12 'Least significant bit

' HD44780 Control lines
Const HD44780_ENABLE As Byte = 13 'to pin 6
'Const HD44780_READWRITE As Byte = 14 '1=Read 0=Write, unused so tied to ground
Const HD44780_REGSELECT As Byte = 15 '1=Data 0=Instruction, to pin 4

Const PID_TEMPERATURE_IN As Byte = 20 'to Pin 20
Const PID_HEAT_OUT As Byte = 19 'to Pin 19
Const PID_COLD_OUT As Byte = 18 'to Pin 18
Const PID_PERIODIC_1_OUT As Byte = 17 'to Pin 17
Const PID_PERIODIC_2_OUT As Byte = 16 'to Pin 16

Const LCDREAD As Byte = 1
Const LCDWRITE As Byte = 0
Const LCDDATA As Byte = 1
Const LCDINSTRUCTION As Byte = 0

Dim sTemperatureActual As Single
Dim sTemperatureActualLast As Single
Dim sTemperatureSetpoint As Single

Dim sHeatProportion As Single
Dim sHeatIntegral As Single
Dim sHeatDerivative As Single

Dim sCoolProportion As Single
Dim sCoolIntegral As Single
Dim sCoolDerivative As Single

Dim sPeriodic1ON As Single
Dim sPeriodic1OFF As Single
Dim sPeriodic1ONTimeOut As Single
Dim sPeriodic1OFFTimeOut As Single

Dim sPeriodic2ON As Single
Dim sPeriodic2OFF As Single
Dim sPeriodic2ONTimeOut As Single
Dim sPeriodic2OFFTimeOut As Single

Dim sTemperatureMin As Single
Dim sTemperatureMax As Single
Dim sTmpMin As Single
Dim sTmpMax As Single

Dim bWorkingDisplay As Boolean
Dim bNewTemperature As Boolean

' global temporary variables used by string functions
Dim sTmpString As String 'used for LCDPrintString
Dim bCount As Byte
Dim bMask As Byte
Dim bByte As Byte
Dim bLength As Byte
Dim bCharPos As Byte
Dim sChar As String * 1
Dim sTmp As String 
Dim bInput As Byte
Dim bField As Byte
Dim sTmpValue As Single 

Dim sComposeSingle As Single
Dim bComposeDecimal As Boolean
Dim bComposeWidth As Byte

Dim TaskStack(0 To 90) As Byte '80 bytes is too small
Dim sTaskInputVolts As Single
Dim sTaskTemp As Single
Dim sTaskSecs As Single

Dim bTaskCount As Byte

Sub Main()

	Delay (0.5) 'in case of rescue
	Call PutPin(26,0) ' green led on

	Call LCDInit()
	Call PIDInit()
	CallTask "MyTask", TaskStack

WorkingDisplayLoop:
	bComposeDecimal = True ' both active fields share these same settings
	bComposeWidth = 6 ' both active fields share these same settings
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,1)
	sTmpString = "Actual Temp:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,13)
	sComposeSingle = sTemperatureActual
	Call PIDComposeValue()
	Call LCDPrintString ()
	Call LCDSendCharacter (bx11011111) 'degrees sign

	Call LCDGotoRowCol(1,4)
	sTmpString = "Setpoint:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,13)
	sComposeSingle = sTemperatureSetpoint
	Call PIDComposeValue()
	Call LCDPrintString ()

	sTmpValue = sTemperatureSetpoint
	Do While (True)
		Sleep (0.0)
		If sTemperatureActual <> sTemperatureActualLast Then
			Call LCDGotoRowCol(0,13)
			sComposeSingle = sTemperatureActual
			bComposeDecimal = True
			bComposeWidth = 6
			Call PIDComposeValue()
			Call LCDPrintString ()
			bNewTemperature = False
			Call LCDGotoRowCol(1, 19) ' Go back to setpoint field
		End If

		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				sTmpValue = sTmpValue + 0.1
				If sTmpValue > 9999.9 Then
					sTmpValue = 9999.9
				End If
			Case INPUT_DOWN
				sTmpValue = sTmpValue - 0.1
				If sTmpValue < -999.9 Then
					sTmpValue = -999.9
				End If
			Case INPUT_COMMIT
				sTemperatureSetpoint = sTmpValue
				Call Sleep (0.2) ' pause for lazy-finger
			Case INPUT_MODE
				GoTo HeatSettingsLoop
		End Select 'bInput
		If (bInput = INPUT_UP) Or (bInput = INPUT_DOWN) Then
			Call LCDGotoRowCol(1, 13)
			sComposeSingle = sTmpValue
			Call PIDComposeValue()
			Call LCDPrintString ()
		End If
	Loop  ' Working Display

HeatSettingsLoop:
	bComposeDecimal = False
	bComposeWidth = 4 
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,0)
	sTmpString = "[Heat PID]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(0,14)
	sTmpString = "Prop:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,19)
	sComposeSingle = sHeatProportion
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,1)
	sTmpString = "Int:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,5)
	sComposeSingle = sHeatIntegral
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,13)
	sTmpString = "Deriv:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,19)
	sComposeSingle = sHeatDerivative
	Call PIDComposeValue()
	Call LCDPrintString ()

	bField = 0
	sTmpValue = sHeatProportion
	Call LCDGotoRowCol(0, 23)

	Do While (True)
		Sleep (0.0)
		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				sTmpValue = sTmpValue + 1.0
				If sTmpValue > 9999.0 Then
					sTmpValue = 9999.0
				End If
			Case INPUT_DOWN
				sTmpValue = sTmpValue - 1.0
				If sTmpValue < 0.0 Then
					sTmpValue = 0.0
				End If
			Case INPUT_COMMIT
				Call Sleep (0.2) ' pause for lazy-finger
				Select Case bField
				Case 0
					sHeatProportion = sTmpValue
					bField = 1
					sTmpValue = sHeatIntegral
					Call LCDGotoRowCol(1, 9)
				Case 1
					sHeatIntegral = sTmpValue
					bField = 2
					sTmpValue = sHeatDerivative
					Call LCDGotoRowCol(1, 23)
				Case 2
					sHeatDerivative = sTmpValue
					bField = 0
					sTmpValue = sHeatProportion
					Call LCDGotoRowCol(0, 23)
				End Select
			Case INPUT_MODE
				GoTo CoolSettingsLoop
		End Select 'bInput

		If (bInput = INPUT_UP) Or (bInput = INPUT_DOWN) Then
			Select Case bField
			Case 0
				Call LCDGotoRowCol(0, 19)
			Case 1
				Call LCDGotoRowCol(1, 5)
			Case 2
				Call LCDGotoRowCol(1, 19)
			End Select
			sComposeSingle = sTmpValue
			Call PIDComposeValue()
			Call LCDPrintString ()
		End If
	Loop  ' Heating PID Settings

CoolSettingsLoop:
	bComposeDecimal = False
	bComposeWidth = 4 
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,0)
	sTmpString = "[Cool PID]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(0,14)
	sTmpString = "Prop:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,19)
	sComposeSingle = sCoolProportion
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,1)
	sTmpString = "Int:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,5)
	sComposeSingle = sCoolIntegral
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,13)
	sTmpString = "Deriv:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,19)
	sComposeSingle = sCoolDerivative
	Call PIDComposeValue()
	Call LCDPrintString ()

	bField = 0
	sTmpValue = sCoolProportion
	Call LCDGotoRowCol(0, 23)

	Do While (True)
		Sleep (0.0)
		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				sTmpValue = sTmpValue + 1.0
				If sTmpValue > 9999.0 Then
					sTmpValue = 9999.0
				End If
			Case INPUT_DOWN
				sTmpValue = sTmpValue - 1.0
				If sTmpValue < 0.0 Then
					sTmpValue = 0.0
				End If
			Case INPUT_COMMIT
				Call Sleep (0.2) ' pause for lazy-finger
				Select Case bField
				Case 0
					sCoolProportion = sTmpValue
					bField = 1
					sTmpValue = sCoolIntegral
					Call LCDGotoRowCol(1, 9)
				Case 1
					sCoolIntegral = sTmpValue
					bField = 2
					sTmpValue = sCoolDerivative
					Call LCDGotoRowCol(1, 23)
				Case 2
					sCoolDerivative = sTmpValue
					bField = 0
					sTmpValue = sCoolProportion
					Call LCDGotoRowCol(0, 23)
				End Select
			Case INPUT_MODE
				GoTo Periodic1SettingsLoop
		End Select 'bInput

		If (bInput = INPUT_UP) Or (bInput = INPUT_DOWN) Then
			Select Case bField
			Case 0
				Call LCDGotoRowCol(0, 19)
			Case 1
				Call LCDGotoRowCol(1, 5)
			Case 2
				Call LCDGotoRowCol(1, 19)
			End Select
			sComposeSingle = sTmpValue
			Call PIDComposeValue()
			Call LCDPrintString ()
		End If
	Loop  ' Cooling PID Settings

Periodic1SettingsLoop:
	bComposeDecimal = True
	bComposeWidth = 6 
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,0)
	sTmpString = "[Periodic 1]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,0)
	sTmpString = "[in Minutes]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(0,14)
	sTmpString = "ON:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,17)
	sComposeSingle = sPeriodic1ON
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,13)
	sTmpString = "OFF:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,17)
	sComposeSingle = sPeriodic1OFF
	Call PIDComposeValue()
	Call LCDPrintString ()

	bField = 0
	sTmpValue = sPeriodic1ON
	Call LCDGotoRowCol(0, 23)
	Do While (True)
		Sleep (0.0)
		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				sTmpValue = sTmpValue + 0.1
				If sTmpValue > 9999.9 Then
					sTmpValue = 9999.9
				End If
			Case INPUT_DOWN
				sTmpValue = sTmpValue - 0.1
				If sTmpValue < 0.0 Then
					sTmpValue = 0.0
				End If
			Case INPUT_COMMIT
				Call Sleep (0.2) ' pause for lazy-finger
				Select Case bField
				Case 0
					sPeriodic1ON = sTmpValue
					sPeriodic1ONTimeOut = Timer() + (sPeriodic1ON * 60.0)
					If sPeriodic1ONTimeOut > 86400.0 Then
						sPeriodic1ONTimeOut = sPeriodic1ONTimeOut - 86400.0
					End If

					bField = 1
					sTmpValue = sPeriodic1OFF
					Call LCDGotoRowCol(1, 23)
				Case 1
					sPeriodic1OFF = sTmpValue
					sPeriodic1OFFTimeOut = Timer() + (sPeriodic1OFF * 60.0)
					If sPeriodic1OFFTimeOut > 86400.0 Then
						sPeriodic1OFFTimeOut = sPeriodic1OFFTimeOut - 86400.0
					End If

					bField = 0
					sTmpValue = sPeriodic1ON
					Call LCDGotoRowCol(0, 23)
				End Select
			Case INPUT_MODE
				GoTo Periodic2SettingsLoop
		End Select 'bInput

		If (bInput = INPUT_UP) Or (bInput = INPUT_DOWN) Then
			Select Case bField
			Case 0
				Call LCDGotoRowCol(0, 17)
			Case 1
				Call LCDGotoRowCol(1, 17)
			End Select
			sComposeSingle = sTmpValue
			Call PIDComposeValue()
			Call LCDPrintString ()
		End If
	Loop  ' Periodic 1 Settings

Periodic2SettingsLoop:
	bComposeDecimal = True
	bComposeWidth = 6 
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,0)
	sTmpString = "[Periodic 2]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,0)
	sTmpString = "[in Minutes]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(0,14)
	sTmpString = "ON:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,17)
	sComposeSingle = sPeriodic2ON
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,13)
	sTmpString = "OFF:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,17)
	sComposeSingle = sPeriodic2OFF
	Call PIDComposeValue()
	Call LCDPrintString ()

	bField = 0
	sTmpValue = sPeriodic2ON
	Call LCDGotoRowCol(0, 23)
	Do While (True)
		Sleep (0.0)
		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				sTmpValue = sTmpValue + 0.1
				If sTmpValue > 9999.9 Then
					sTmpValue = 9999.9
				End If
			Case INPUT_DOWN
				sTmpValue = sTmpValue - 0.1
				If sTmpValue < 0.0 Then
					sTmpValue = 0.0
				End If
			Case INPUT_COMMIT
				Call Sleep (0.2) ' pause for lazy-finger
				Select Case bField
				Case 0
					sPeriodic2ON = sTmpValue
					bField = 1
					sTmpValue = sPeriodic2OFF
					Call LCDGotoRowCol(1, 23)
				Case 1
					sPeriodic2OFF = sTmpValue
					bField = 0
					sTmpValue = sPeriodic2ON
					Call LCDGotoRowCol(0, 23)
				End Select
			Case INPUT_MODE
				GoTo MinMAxTempLoop
		End Select 'bInput
	Loop  ' Periodic2SettingsLoop

MinMAxTempLoop:
	sTmpMin = sTemperatureMin
	sTmpMax = sTemperatureMax

	bComposeDecimal = True
	bComposeWidth = 6 
	Call LCDClearDisplay()

	Call LCDGotoRowCol(0,0)
	sTmpString = "[Min Max]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,0)
	sTmpString = "[Reset  ]"
	Call LCDPrintString ()

	Call LCDGotoRowCol(0,12)
	sTmpString = "Min:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(0,16)
	sComposeSingle = sTemperatureMin
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1,12)
	sTmpString = "Max:"
	Call LCDPrintString ()
	Call LCDGotoRowCol(1,16)
	sComposeSingle = sTemperatureMax
	Call PIDComposeValue()
	Call LCDPrintString ()

	Call LCDGotoRowCol(1, 7)
	Do While (True)
		Sleep (0.0)
		bInput = PIDGetButton()
		Select Case bInput
			Case INPUT_UP
				Sleep (0.0)
			Case INPUT_DOWN
				Sleep (0.0)
			Case INPUT_COMMIT ' reset min max values to current temperature
				Call Sleep (0.2) ' pause for lazy-finger
				sTemperatureMin = sTemperatureActual
				sTemperatureMax = sTemperatureMin

				Call LCDGotoRowCol(0,16)
				sComposeSingle = sTemperatureMin
				Call PIDComposeValue()
				Call LCDPrintString ()

				Call LCDGotoRowCol(1,16)
				sComposeSingle = sTemperatureMax
				Call PIDComposeValue()
				Call LCDPrintString ()

				Call LCDGotoRowCol(1, 7)
			Case INPUT_MODE
				GoTo WorkingDisplayLoop
		End Select 'bInput

		If sTemperatureMin < sTmpMin Then
			sTmpMin = sTemperatureMin
			Call LCDGotoRowCol(0,16)
			sComposeSingle = sTemperatureMin
			Call PIDComposeValue()
			Call LCDPrintString ()
			Call LCDGotoRowCol(1, 7) ' reset prompt
		End If

		If sTemperatureMax > sTmpMax Then
			sTmpMax = sTemperatureMax
			Call LCDGotoRowCol(1,16)
			sComposeSingle = sTemperatureMax
			Call PIDComposeValue()
			Call LCDPrintString ()
			Call LCDGotoRowCol(1, 7) ' reset prompt
		End If
	Loop  ' Min Max Report

	Call PutPin(26,1) ' green led off
End Sub 'Main

Sub MyTask ()
	Dim bToggleLED As Byte ' Remove finally, just an 'alive' signal

	bToggleLED = 0
	Do While (True) ' forever
		Call PutPin(25, bToggleLED)

		sTaskTemp = sTemperatureActual / 500.0
		For bTaskCount = 1 to 10 
			Call GetADC(PID_TEMPERATURE_IN, sTaskInputVolts)
			sTaskTemp = sTaskTemp + ((sTaskInputVolts - sTaskTemp)/100.0) 'smoothes value jumps
			Call Sleep (0.01)
		Next
		sTemperatureActualLast = sTemperatureActual
		sTemperatureActual = sTaskTemp * 500.0
		sTemperatureActual = CSng(CLng(sTemperatureActual * 10.0))/10.0 'trunc to 0.1

		' --- Set Min Max temperatures
		If sTemperatureActual > sTemperatureMax Then
			sTemperatureMax = sTemperatureActual
		End If

		If sTemperatureActual < sTemperatureMin Then
			sTemperatureMin = sTemperatureActual
		End If

		' --- Adjust warming/cooling
		' If too warm..
		' -- Stub
		If ((sTemperatureActual - sTemperatureSetpoint) > 1.0) Then ' hysteresis
			'turn on cool-out
		End If
		
		' If too cool..
		If ((sTemperatureSetpoint - sTemperatureActual) < 1.0) Then ' hysteresis
			'turn off warm-out
		End If

		' pulse warm output according to proportional band
		' -- Stub

		' -- Adjust periodic1/periodic2 output
		' -- Stub

'sPeriodic1ON
'sPeriodic1ONTimeOut

'sPeriodic1OFF
'sPeriodic1OFFTimeOut

'sPeriodic2ON
'sPeriodic2OFF
'sPeriodic2ONTimeOut
'sPeriodic2OFFTimeOut

		' -- Remove finally, just an 'alive' signal
		if bToggleLED = 1 Then
			bToggleLED = 0
		Else
			bToggleLED = 1
		End If
		Call Sleep (0.5)
	Loop
End Sub


Function PIDGetButton () As Byte
	If GetPin(INPUT_UP) = 0 Then
		Call Sleep (0.1) 'debounce
		PIDGetButton = INPUT_UP
		Exit Function
	ElseIf GetPin(INPUT_DOWN) = 0 Then
		Call Sleep (0.1) 'debounce
		PIDGetButton = INPUT_DOWN
		Exit Function
	ElseIf GetPin(INPUT_COMMIT) = 0 Then
		Call Sleep (0.1) 'debounce
		PIDGetButton = INPUT_COMMIT
		Exit Function
	ElseIf GetPin(INPUT_MODE) = 0 Then
		Call Sleep (0.1) 'debounce
		PIDGetButton = INPUT_MODE
		Exit Function
	Else
		PIDGetButton = 0
		Exit Function
	End If
End Function


' Left-pads string with spaces. 
Sub PIDComposeValue()
	If bComposeDecimal = True Then
		sTmp = CStr(CLng(sComposeSingle * 10.0))
	Else
		sTmp = CStr(CLng(sComposeSingle))
	End If
	bLength = CByte(Len(sTmp))

	bCount = bLength
	If bComposeDecimal = True Then
		bCount = bCount + 1 ' for the decimal point
		If Abs(sComposeSingle) < 1.0 Then
			bCount = bCount + 1 ' for the leading zero
		End If
	End If		

	sTmpString = ""
	Do While (bComposeWidth - bCount > 0)
		sTmpString = sTmpString & " "
		bCount = bCount + 1
	Loop

	sTmpString = sTmpString & Mid(sTmp, 1, CInt(bLength-1))
	If bComposeDecimal = True Then 
		If Abs(sComposeSingle) < 1.0 Then
			sTmpString = sTmpString & "0"
		End If
		sTmpString = sTmpString & "."
	End If
	sTmpString = sTmpString & Mid(sTmp, CInt(bLength), 1)
End Sub


'Prints the global string sTmpString
Sub LCDPrintString ()
	Call PutPin(HD44780_REGSELECT, LCDDATA)
	For bCharPos = 1 To CByte(Len(sTmpString))
		sChar = Mid(sTmpString, CInt(bCharPos), 1)
		bByte = Asc(sChar)
		bMask = bx10000000
		For bCount = 0 to 3 'Put most significant bits first
			Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
			bMask = bMask \ 2
		Next
		Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
		For bCount = 0 to 3 'Put next 4 bits
			Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
			bMask = bMask \ 2
		Next
		Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
		Call Sleep(0.0005)
	Next
End Sub ' LCDPrintString


Sub PIDInit ()
	Call PutPin(INPUT_MODE, bxInputPullup) ' Pull-up
	Call PutPin(INPUT_UP, bxInputPullup) ' Pull-up
	Call PutPin(INPUT_DOWN, bxInputPullup) ' Pull-up
	Call PutPin(INPUT_COMMIT, bxInputPullup) ' Pull-up

	bWorkingDisplay = False
	bNewTemperature = False
	Call GetADC(PID_TEMPERATURE_IN, sTemperatureActual)
	sTemperatureActual = sTemperatureActual * 500.0
	sTemperatureActualLast = sTemperatureActual

	sTemperatureSetpoint = 68.0

	sHeatProportion = 40.0
	sHeatIntegral = 10.0
	sHeatDerivative = 0.0

	sCoolProportion = 40.0
	sCoolIntegral = 10.0
	sCoolDerivative = 0.0

	sPeriodic1ON = 0.1
	sPeriodic1OFF = 59.9
	sPeriodic1ONTimeOut = 0.0
	sPeriodic1OFFTimeOut = 0.0

	sPeriodic2ON = 720.0
	sPeriodic2OFF = 720.0
	sPeriodic2ONTimeOut = 0.0
	sPeriodic2OFFTimeOut = 0.0
End Sub

Sub LCDInit()
	Call PutPin(HD44780_ENABLE, bxOutputLow)
	Call PutPin(HD44780_REGSELECT, bxOutputLow)
	Call Sleep(0.050) 'for LCD chip startup

	Call LCDPut4Bits ( bx00110000 ) 'function set (assumes 8-bit at startup)
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.005)
	Call LCDPut4Bits ( bx00110000 ) 'function set (assumes 8-bit at startup)
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.00015)
	Call LCDPut4Bits ( bx00110000 ) 'function set (assumes 8-bit at startup)
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call LCDPut4Bits ( bx00100000 ) 'Now actually sets to 4-bit mode
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)

	Call LCDFunctionSet () 'sets the complete function set
	Call LCDDisplayOFF ()
	Call LCDClearDisplay ()
	Call LCDEntryModeSet ()
	Call LCDDisplayON ()
End Sub

Sub LCDFunctionSet8 () '8-bit, 2 lines, no-scroll, blinking cursor
	Call LCDSendCommand ( bx00111000 )
End Sub

Sub LCDFunctionSet () '4-bit, 2 lines, no-scroll, blinking cursor
	Call LCDSendCommand ( bx00101000 )
End Sub

Sub LCDDisplayON ()
	Call LCDSendCommand ( bx00001111 )
End Sub

Sub LCDDisplayOFF ()
	Call LCDSendCommand ( bx00001000 )
End Sub

Sub LCDEntryModeSet ()
	Call LCDSendCommand ( bx00000110 )
End Sub

Sub LCDClearDisplay ()
	Call PutPin(HD44780_ENABLE, bxOutputLow)
	Call PutPin(HD44780_REGSELECT, LCDINSTRUCTION)

	Call PutPin(HD44780_DB3,0)
	Call PutPin(HD44780_DB2,0)
	Call PutPin(HD44780_DB1,0)
	Call PutPin(HD44780_DB0,0)
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call PutPin(HD44780_DB3,0)
	Call PutPin(HD44780_DB2,0)
	Call PutPin(HD44780_DB1,0)
	Call PutPin(HD44780_DB0,1)
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.0016) 'Clear Display needs more time
End Sub

Sub LCDReturnHome ()
	Call LCDSendCommand ( bx00000010 )
	Call Sleep(0.0016)
End Sub


Sub LCDGotoRowCol (ByVal bRow As Byte, ByVal bCol As Byte)
	Call PutPin(HD44780_REGSELECT, LCDINSTRUCTION)
	Call PutPin(HD44780_ENABLE, bxOutputLow)

	bByte = bx10000000 Or (bRow * 64 + bCol)
	bMask = bx10000000
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	For bCount = 0 to 3 'Put next 4 bits
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.00005)
End Sub

'Sub LCDSetDDRAMAddr (ByVal bAddr As Byte)
'	Call LCDSendCommand ( bx10000000 Or bAddr) 'bAddr is 7-bits
'End Sub

Sub LCDSendCommand (ByVal bByte As Byte)
	Call PutPin(HD44780_REGSELECT, LCDINSTRUCTION)
	Call PutPin(HD44780_ENABLE, bxOutputLow)

	bMask = bx10000000
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.00005)
End Sub

Sub LCDSendCharacter (ByVal bByte As Byte)
	Call PutPin(HD44780_REGSELECT, LCDDATA)
	Call PutPin(HD44780_ENABLE, bxOutputLow)

	bMask = bx10000000
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	For bCount = 0 to 3 'Put next 4 bits
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	Call Sleep(0.00005)
End Sub

' 4-bit interface - ENABLE pulse expects WRITE mode 
Sub LCDPutByte (ByVal bByte As Byte)
	bMask = bx10000000
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))

		bMask = bMask \ 2
	Next
	Call PulseOut(HD44780_ENABLE, 0.00005, bxOutputHigh)
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
End Sub 

Sub LCDPut4Bits (ByVal bByte As Byte) 'msb's only
	bMask = bx10000000
	For bCount = 0 to 3 'Put most significant bits first
		Call PutPin(HD44780_DB3 + bCount, ((bByte And bMask)\bMask))
		bMask = bMask \ 2
	Next
End Sub