Unit HD44780

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Description

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The Hitachi HD44780 is a dot matrix liquid crystal display controller. It supports 5x8 or 5x10 characters and includes a 240 character font in ROM, 80 bytes of character RAM and 64 bytes of character generator RAM for custom characters.

The device support 4 bit or 8 bit modes, and has a range of standard functions for display clear, display on/off, cursor on/off, character blink, cursor shift etc.

This unit creates a Console device to represent the LCD and provides the standard console device functions (where appropriate) to draw text, clear the screen, scroll text and manage the cursor.

Currently only 4 bit mode is supported but extension to include 8 bit mode is possible with some additional setup and support functions.

Constants

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To be documented

Type definitions

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To be documented

Public variables

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To be documented

Function declarations

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HD44780 functions

function HD44780ConsoleCreate(GPIO:PGPIODevice; const Name:String; Width,Height,RS,RW,EN,D4,D5,D6,D7:LongWord):PConsoleDevice;

Description: To be documented

Note	None documented

function HD44780ConsoleDestroy(Console:PConsoleDevice):LongWord;

Description: To be documented

Note	None documented

HD44780 console functions

function HD44780ConsoleOpen(Console:PConsoleDevice):LongWord;

Description: Implementation of ConsoleDeviceOpen API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceOpen instead

function HD44780ConsoleClose(Console:PConsoleDevice):LongWord;

Description: Implementation of ConsoleDeviceClose API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceClose instead

function HD44780ConsoleClear(Console:PConsoleDevice; Color:LongWord):LongWord;

Description: Implementation of ConsoleDeviceClear API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceClear instead

function HD44780ConsoleScroll(Console:PConsoleDevice; X1,Y1,X2,Y2,Count,Direction:LongWord):LongWord;

Description: Implementation of ConsoleDeviceScroll API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceScroll instead

function HD44780ConsoleDrawChar(Console:PConsoleDevice; Handle:TFontHandle; Ch:Char; X,Y,Forecolor,Backcolor:LongWord):LongWord;

Description: Implementation of ConsoleDeviceDrawChar API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceDrawChar instead

function HD44780ConsoleDrawText(Console:PConsoleDevice; Handle:TFontHandle; const Text:String; X,Y,Forecolor,Backcolor,Len:LongWord):LongWord;

Description: Implementation of ConsoleDeviceDrawText API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceDrawText instead

function HD44780ConsoleDrawBlock(Console:PConsoleDevice; X1,Y1,X2,Y2,Color:LongWord):LongWord;

Description: Implementation of ConsoleDeviceDrawBlock API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceDrawBlock instead

function HD44780ConsoleDrawWindow(Console:PConsoleDevice; Handle:TWindowHandle):LongWord;

Description: Implementation of ConsoleDeviceDrawWindow API for HD44780

Note	Caller must hold the Window lock Not intended to be called directly by applications, use ConsoleDeviceDrawWindow instead

function HD44780ConsolePutText(Console:PConsoleDevice; Handle:TFontHandle; const Source,Dest:TConsolePoint; Buffer:PConsoleChar; Width,Height,Skip:LongWord):LongWord;

Description: Implementation of ConsoleDevicePutText API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDevicePutText instead

function HD44780ConsoleGetPosition(Console:PConsoleDevice; Position:LongWord; var X1,Y1,X2,Y2:LongWord):LongWord;

Description: Implementation of ConsoleDeviceGetPosition API for HD44780

Note	Not intended to be called directly by applications, use ConsoleDeviceGetPosition instead

HD44780 helper functions

function HD44780WriteChar(Console:PHD44780Console; Ch:Char):LongWord;

Description: Write character data to the HD44780 device

Note	Caller must hold the Console lock

function HD44780WriteData(Console:PHD44780Console; Value:Byte):LongWord;

Description: Write command data to the HD44780 device

Note	Caller must hold the Console lock

function HD44780PulseEnable(Console:PHD44780Console):LongWord;

Description: Pulse the clock enable line off, on, off to send a command

Note	Caller must hold the Console lock

function HD44780CursorHome(Console:PHD44780Console):LongWord;

Description: Return the cursor to the top left corner

Note	Caller must hold the Console lock

function HD44780CursorBlink(Console:PHD44780Console; Blink:Boolean):LongWord;

Description: Set the cursor blinking to on or off

Note	Caller must hold the Console lock

function HD44780CursorVisible(Console:PHD44780Console; Visible:Boolean):LongWord;

Description: Set the cursor to visible or not visible

Note	Caller must hold the Console lock

function HD44780CursorPosition(Console:PHD44780Console; Row,Col:Byte):LongWord;

Description: Set the cursor position to Row, Col

Note	Caller must hold the Console lock

function HD44780DisplayEnabled(Console:PHD44780Console; Enabled:Boolean):LongWord;

Description: Set the display state to on or off

Note	Caller must hold the Console lock

function HD44780AddCharacter(Console:PHD44780Console; Location:Byte; Character:THD44780Character):LongWord;

Description: Add a custom character to the display

Note	Caller must hold the Console lock

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