Difference between revisions of "Unit HD44780"

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----
 
----
  
''To be documented''
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'''HD44780 character types'''
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<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial;">
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<code>PHD44780Character = ^THD44780Character;</code>
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<code>THD44780Character = array[0..7] of Byte;</code>
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<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
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{| class="wikitable" style="font-size: 14px; background: white;"
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|-
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| &nbsp;
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| style="width: 50%;"|&nbsp;
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|-
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|}
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</div></div>
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'''HD44780 console types'''
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<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial;">
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<code>PHD44780Console = ^THD44780Console;</code>
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<code>THD44780Console = record</code>
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<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
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{| class="wikitable" style="font-size: 14px; background: white;"
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|-
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|colspan="2"|''Console Properties''
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|-
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| <code>Console:TConsoleDevice;</code>
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| &nbsp;
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|-
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|colspan="2"|''HD44780 Properties''
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|-
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| <code>GPIO:PGPIODevice;</code>
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| The GPIO device this Console is connected to
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|-
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| <code>RS:LongWord;</code>
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| The GPIO pin for the RS line
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|-
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| <code>RW:LongWord;</code>
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| The GPIO pin for the RW line
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|-
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| <code>EN:LongWord;</code>
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| The GPIO pin for the EN line
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|-
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| <code>D4:LongWord;</code>
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| The GPIO pin for the D4 line
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|-
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| <code>D5:LongWord;</code>
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| The GPIO pin for the D5 line
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|-
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| <code>D6:LongWord;</code>
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| The GPIO pin for the D6 line
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|-
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| <code>D7:LongWord;</code>
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| The GPIO pin for the D7 line
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|-
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| <code>EntryMode:Byte;</code>
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| Current value of the Entry Mode settings
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|-
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| <code>FunctionSet:Byte;</code>
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| Current value of the Function Set settings
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|-
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| <code>DisplayControl:Byte;</code>
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| Current value of the Display Control settings
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|-
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|colspan="2"|''Cursor Properties''
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|-
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| <code>CursorX:Byte;</code>
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| &nbsp;
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|-
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| <code>CursorY:Byte;</code>
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| &nbsp;
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|-
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|colspan="2"|''Buffer Properties''
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|-
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| <code>Size:LongWord;</code>
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| &nbsp;
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|-
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| <code>Buffer:PByte;</code>
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| &nbsp;
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|-
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|}
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</div></div>
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<br />
  
 
=== Public variables ===
 
=== Public variables ===

Revision as of 04:14, 19 January 2017

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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



HD44780 character types

PHD44780Character = ^THD44780Character;

THD44780Character = array[0..7] of Byte;

   

HD44780 console types

PHD44780Console = ^THD44780Console;

THD44780Console = record

Console Properties
Console:TConsoleDevice;  
HD44780 Properties
GPIO:PGPIODevice; The GPIO device this Console is connected to
RS:LongWord; The GPIO pin for the RS line
RW:LongWord; The GPIO pin for the RW line
EN:LongWord; The GPIO pin for the EN line
D4:LongWord; The GPIO pin for the D4 line
D5:LongWord; The GPIO pin for the D5 line
D6:LongWord; The GPIO pin for the D6 line
D7:LongWord; The GPIO pin for the D7 line
EntryMode:Byte; Current value of the Entry Mode settings
FunctionSet:Byte; Current value of the Function Set settings
DisplayControl:Byte; Current value of the Display Control settings
Cursor Properties
CursorX:Byte;  
CursorY:Byte;  
Buffer Properties
Size:LongWord;  
Buffer:PByte;  


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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