View source for Unit HD44780

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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 ===
----


<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 specific constants''' <code> HD44780_CONSOLE_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_CONSOLE_DESCRIPTION = 'Hitachi HD44780 LCD Controller';</code>
| Description of HD44780 device
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 instruction''' <code> HD44780_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_CLEARDISPLAY = $01;</code>
| style="width: 50%;"|&nbsp;
|-
| <code>HD44780_RETURNHOME = $02;</code>
| &nbsp;
|-
| <code>HD44780_ENTRYMODESET = $04;</code>
| &nbsp;
|-
| <code>HD44780_DISPLAYCONTROL = $08;</code>
| &nbsp;
|-
| <code>HD44780_CURSORSHIFT = $10;</code>
| &nbsp;
|-
| <code>HD44780_FUNCTIONSET = $20;</code>
| &nbsp;
|-
| <code>HD44780_SETCGRAMADDR = $40;</code>
| &nbsp;
|-
| <code>HD44780_SETDDRAMADDR = $80;</code>
| &nbsp;
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 entry mode set''' <code> HD44780_ENTRYMODESET_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_ENTRYMODESET_RIGHT = $00;</code>
| style="width: 50%;"|&nbsp;
|-
| <code>HD44780_ENTRYMODESET_LEFT = $02;</code>
| &nbsp;
|-
| <code>HD44780_ENTRYMODESET_SHIFTINC = $01;</code>
| &nbsp;
|-
| <code>HD44780_ENTRYMODESET_SHIFTDEC = $00;</code>
| &nbsp;
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 display control''' <code> HD44780_DISPLAYCONTROL_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_DISPLAYCONTROL_DISPLAYON = $04;</code>
| style="width: 50%;"|&nbsp;
|-
| <code>HD44780_DISPLAYCONTROL_DISPLAYOFF = $00;</code>
| &nbsp;
|-
| <code>HD44780_DISPLAYCONTROL_CURSORON = $02;</code>
| &nbsp;
|-
| <code>HD44780_DISPLAYCONTROL_CURSOROFF = $00;</code>
| &nbsp;
|-
| <code>HD44780_DISPLAYCONTROL_BLINKON = $01;</code>
| &nbsp;
|-
| <code>HD44780_DISPLAYCONTROL_BLINKOFF = $00;</code>
| &nbsp;
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 cursor shift''' <code> HD44780_CURSORSHIFT_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_CURSORSHIFT_DISPLAY = $08;</code>
| style="width: 50%;"|&nbsp;
|-
| <code>HD44780_CURSORSHIFT_CURSOR = $00;</code>
| &nbsp;
|-
| <code>HD44780_CURSORSHIFT_RIGHT = $04;</code>
| &nbsp;
|-
| <code>HD44780_CURSORSHIFT_LEFT = $00;</code>
| &nbsp;
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 function set''' <code> HD44780_FUNCTIONSET_* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| <code>HD44780_FUNCTIONSET_8BITMODE = $10;</code>
| style="width: 50%;"|&nbsp;
|-
| <code>HD44780_FUNCTIONSET_4BITMODE = $00;</code>
| &nbsp;
|-
| <code>HD44780_FUNCTIONSET_2LINE = $08;</code>
| &nbsp;
|-
| <code>HD44780_FUNCTIONSET_1LINE = $00;</code>
| &nbsp;
|-
| <code>HD44780_FUNCTIONSET_5X10DOTS = $04;</code>
| &nbsp;
|-
| <code>HD44780_FUNCTIONSET_5X8DOTS = $00;</code>
| &nbsp;
|-
|}
</div></div>
<br /> 
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
<div style="font-size: 14px; padding-left: 12px;">'''HD44780 row offset''' <code> HD44780_ROW_OFFSETS* </code></div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
|colspan="2"|4 rows
|-
|colspan="2"|<code>HD44780_ROW_OFFSETS:array[0..3] of Byte = ($00,$40,$14,$54);</code>
|-
|}
</div></div>
<br />

=== Type definitions ===
----


'''HD44780 character'''

<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial;">
<code>PHD44780Character = ^THD44780Character;</code>

<code>THD44780Character = array[0..7] of Byte;</code>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
| &nbsp;
| style="width: 50%;"|&nbsp;
|-
|}
</div></div>

'''HD44780 console'''

<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial;">
<code>PHD44780Console = ^THD44780Console;</code>

<code>THD44780Console = record</code>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
|colspan="2"|''Console Properties''
|-
| <code>Console:TConsoleDevice;</code>
| &nbsp;
|-
|colspan="2"|''HD44780 Properties''
|-
| <code>GPIO:PGPIODevice;</code>
| The GPIO device this Console is connected to
|-
| <code>RS:LongWord;</code>
| The GPIO pin for the RS line
|-
| <code>RW:LongWord;</code>
| The GPIO pin for the RW line
|-
| <code>EN:LongWord;</code>
| The GPIO pin for the EN line
|-
| <code>D4:LongWord;</code>
| The GPIO pin for the D4 line
|-
| <code>D5:LongWord;</code>
| The GPIO pin for the D5 line
|-
| <code>D6:LongWord;</code>
| The GPIO pin for the D6 line
|-
| <code>D7:LongWord;</code>
| The GPIO pin for the D7 line
|-
| <code>EntryMode:Byte;</code>
| Current value of the Entry Mode settings
|-
| <code>FunctionSet:Byte;</code>
| Current value of the Function Set settings
|-
| <code>DisplayControl:Byte;</code>
| Current value of the Display Control settings
|-
|colspan="2"|''Cursor Properties''
|-
| <code>CursorX:Byte;</code>
| &nbsp;
|-
| <code>CursorY:Byte;</code>
| &nbsp;
|-
|colspan="2"|''Buffer Properties''
|-
| <code>Size:LongWord;</code>
| &nbsp;
|-
| <code>Buffer:PByte;</code>
| &nbsp;
|-
|}
</div></div>
<br />

=== Public variables ===
----

''None defined''

=== Function declarations ===
----


'''HD44780 functions'''

<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleCreate(GPIO:PGPIODevice; const Name:String; Width,Height,RS,RW,EN,D4,D5,D6,D7:LongWord):PConsoleDevice;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| None documented
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleDestroy(Console:PConsoleDevice):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| None documented
|-
|}
</div></div>
<br />

'''HD44780 console functions'''

<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleOpen(Console:PConsoleDevice):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceOpen API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceOpen instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleClose(Console:PConsoleDevice):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceClose API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceClose instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleClear(Console:PConsoleDevice; Color:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceClear API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceClear instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleScroll(Console:PConsoleDevice; X1,Y1,X2,Y2,Count,Direction:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceScroll API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceScroll instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleDrawChar(Console:PConsoleDevice; Handle:TFontHandle; Ch:Char; X,Y,Forecolor,Backcolor:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceDrawChar API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceDrawChar instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleDrawText(Console:PConsoleDevice; Handle:TFontHandle; const Text:String; X,Y,Forecolor,Backcolor,Len:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceDrawText API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceDrawText instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleDrawBlock(Console:PConsoleDevice; X1,Y1,X2,Y2,Color:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceDrawBlock API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceDrawBlock instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleDrawWindow(Console:PConsoleDevice; Handle:TWindowHandle; Flags:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceDrawWindow API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Window lock
Not intended to be called directly by applications, use ConsoleDeviceDrawWindow instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsolePutText(Console:PConsoleDevice; Handle:TFontHandle; const Source,Dest:TConsolePoint; Buffer:PConsoleChar; Width,Height,Skip:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDevicePutText API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDevicePutText instead
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780ConsoleGetPosition(Console:PConsoleDevice; Position:LongWord; var X1,Y1,X2,Y2:LongWord):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Implementation of ConsoleDeviceGetPosition API for HD44780</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Not intended to be called directly by applications, use ConsoleDeviceGetPosition instead
|-
|}
</div></div>
<br />

'''HD44780 helper functions'''

<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780WriteChar(Console:PHD44780Console; Ch:Char):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Write character data to the HD44780 device</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780WriteData(Console:PHD44780Console; Value:Byte):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Write command data to the HD44780 device</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780PulseEnable(Console:PHD44780Console):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Pulse the clock enable line off, on, off to send a command</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780CursorHome(Console:PHD44780Console):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Return the cursor to the top left corner</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780CursorBlink(Console:PHD44780Console; Blink:Boolean):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the cursor blinking to on or off</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780CursorVisible(Console:PHD44780Console; Visible:Boolean):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the cursor to visible or not visible</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780CursorPosition(Console:PHD44780Console; Row,Col:Byte):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the cursor position to Row, Col</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780DisplayEnabled(Console:PHD44780Console; Enabled:Boolean):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the display state to on or off</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
<pre style="border: 0; padding-bottom:0px;">function HD44780AddCharacter(Console:PHD44780Console; Location:Byte; Character:THD44780Character):LongWord;</pre>
<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Add a custom character to the display</div>
<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
{| class="wikitable" style="font-size: 14px; background: white;"
|-
! '''Note'''
| Caller must hold the Console lock
|-
|}
</div></div>
<br />

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