Difference between revisions of "Unit HD44780"

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''To be documented''
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''None defined''
  
 
=== Function declarations ===
 
=== Function declarations ===

Revision as of 02:43, 30 December 2016

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Description


Hitachi HD44780 LCD controller Driver unit

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



HD44780 specific constants HD44780_CONSOLE_*
HD44780_CONSOLE_DESCRIPTION = 'Hitachi HD44780 LCD Controller'; Description of HD44780 device


HD44780 instruction constants HD44780_*
HD44780_CLEARDISPLAY = $01;  
HD44780_RETURNHOME = $02;  
HD44780_ENTRYMODESET = $04;  
HD44780_DISPLAYCONTROL = $08;  
HD44780_CURSORSHIFT = $10;  
HD44780_FUNCTIONSET = $20;  
HD44780_SETCGRAMADDR = $40;  
HD44780_SETDDRAMADDR = $80;  


HD44780 entry mode set constants HD44780_ENTRYMODESET_*
HD44780_ENTRYMODESET_RIGHT = $00;  
HD44780_ENTRYMODESET_LEFT = $02;  
HD44780_ENTRYMODESET_SHIFTINC = $01;  
HD44780_ENTRYMODESET_SHIFTDEC = $00;  


HD44780 display control constants HD44780_DISPLAYCONTROL_*
HD44780_DISPLAYCONTROL_DISPLAYON = $04;  
HD44780_DISPLAYCONTROL_DISPLAYOFF = $00;  
HD44780_DISPLAYCONTROL_CURSORON = $02;  
HD44780_DISPLAYCONTROL_CURSOROFF = $00;  
HD44780_DISPLAYCONTROL_BLINKON = $01;  
HD44780_DISPLAYCONTROL_BLINKOFF = $00;  


HD44780 cursor shift constants HD44780_CURSORSHIFT_*
HD44780_CURSORSHIFT_DISPLAY = $08;  
HD44780_CURSORSHIFT_CURSOR = $00;  
HD44780_CURSORSHIFT_RIGHT = $04;  
HD44780_CURSORSHIFT_LEFT = $00;  


HD44780 function set constants HD44780_FUNCTIONSET_*
HD44780_FUNCTIONSET_8BITMODE = $10;  
HD44780_FUNCTIONSET_4BITMODE = $00;  
HD44780_FUNCTIONSET_2LINE = $08;  
HD44780_FUNCTIONSET_1LINE = $00;  
HD44780_FUNCTIONSET_5X10DOTS = $04;  
HD44780_FUNCTIONSET_5X8DOTS = $00;  


HD44780 row offset constants HD44780_ROW_OFFSETS*
4 rows
HD44780_ROW_OFFSETS:array[0..3] of Byte = ($00,$40,$14,$54);


Type definitions


To be documented

Public variables


None defined

Function declarations



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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