SPI Lcd Library

The mikroBasic PRO for PIC provides a library for communication with Lcd (with HD44780 compliant controllers) in 4-bit mode via SPI interface.

For creating a custom set of Lcd characters use Lcd Custom Character Tool.

  Important :

Library Dependency Tree

SPI Lcd Library Dependency Tree

External dependencies of SPI Lcd Library

The implementation of SPI Lcd Library routines is based on Port Expander Library routines.

External dependencies are the same as Port Expander Library external dependencies.

Library Routines

SPI_Lcd_Config

Prototype

sub procedure SPI_Lcd_Config(dim DeviceAddress as byte)

Returns

Nothing.

Description

Initializes the Lcd module via SPI interface.

Parameters :

  • DeviceAddress: SPI expander hardware address, see schematic at the bottom of this page

Requires Global variables :
  • SPExpanderCS: Chip Select line
  • SPExpanderRST: Reset line
  • SPExpanderCS_Direction: Direction of the Chip Select pin
  • SPExpanderRST_Direction: Direction of the Reset pin
must be defined before using this function.


SPI module needs to be initialized. See SPI1_Init and SPI1_Init_Advanced routines.

Example
' port expander pinout definition
dim SPExpanderRST as sbit at RC0_bit
    SPExpanderCS as sbit at RC1_bit
    SPExpanderRST_Direction as sbit at TRISC0_bit
    SPExpanderCS_Direction as sbit at TRISC1_bit
' end of port expander pinout definition
...  
' If Port Expander Library uses SPI1 module
SPI1_Init()                   ' Initialize SPI module used with PortExpander
SPI_Lcd_Config(0)             ' initialize lcd over spi interface

SPI_Lcd_Out

Prototype

sub procedure SPI_Lcd_Out(dim row as byte, dim column as byte, dim byref text as string)

Returns

Nothing.

Description

Prints text on the Lcd starting from specified position. Both string variables and literals can be passed as a text.

Parameters :

  • row: starting position row number
  • column: starting position column number
  • text: text to be written

Requires

Lcd needs to be initialized for SPI communication, see SPI_Lcd_Config routines.

Example
' Write text "Hello!" on Lcd starting from row 1, column 3:
SPI_Lcd_Out(1, 3, "Hello!")

SPI_Lcd_Out_CP

Prototype

sub procedure SPI_Lcd_Out_CP(dim text as string)

Returns

Nothing.

Description

Prints text on the Lcd at current cursor position. Both string variables and literals can be passed as a text.

Parameters :

  • text: text to be written

Requires

Lcd needs to be initialized for SPI communication, see SPI_Lcd_Config routines.

Example
' Write text "Here!" at current cursor position:
SPI_Lcd_Out_CP("Here!")

SPI_Lcd_Chr

Prototype

sub procedure SPI_Lcd_Chr(dim Row as byte, dim Column as byte, dim Out_Char as byte)

Returns

Nothing.

Description

Prints character on Lcd at specified position. Both variables and literals can be passed as character.

Parameters :

  • Row: writing position row number
  • Column: writing position column number
  • Out_Char: character to be written

Requires

Lcd needs to be initialized for SPI communication, see SPI_Lcd_Config routines.

Example
' Write character "i" at row 2, column 3:
SPI_Lcd_Chr(2, 3, "i")

SPI_Lcd_Chr_CP

Prototype

sub procedure SPI_Lcd_Chr_CP(dim Out_Char as byte)

Returns

Nothing.

Description

Prints character on Lcd at current cursor position. Both variables and literals can be passed as character.

Parameters :

  • Out_Char: character to be written

Requires

Lcd needs to be initialized for SPI communication, see SPI_Lcd_Config routines.

Example
' Write character "e" at current cursor position:
SPI_Lcd_Chr_Cp("e")

SPI_Lcd_Cmd

Prototype

sub procedure SPI_Lcd_Cmd(dim out_char as byte)

Returns

Nothing.

Description

Sends command to Lcd.

Parameters :

  • out_char: command to be sent

  Note : Predefined constants can be passed to the function, see Available SPI Lcd Commands.
Requires

Lcd needs to be initialized for SPI communication, see SPI_Lcd_Config routines.

Example
' Clear Lcd display:
SPI_Lcd_Cmd(_LCD_CLEAR)

Available SPI Lcd Commands

SPI Lcd Command Purpose
_LCD_FIRST_ROW Move cursor to the 1st row
_LCD_SECOND_ROW Move cursor to the 2nd row
_LCD_THIRD_ROW Move cursor to the 3rd row
_LCD_FOURTH_ROW Move cursor to the 4th row
_LCD_CLEAR Clear display
_LCD_RETURN_HOME Return cursor to home position, returns a shifted display to its original position. Display data RAM is unaffected.
_LCD_CURSOR_OFF Turn off cursor
_LCD_UNDERLINE_ON Underline cursor on
_LCD_BLINK_CURSOR_ON Blink cursor on
_LCD_MOVE_CURSOR_LEFT Move cursor left without changing display data RAM
_LCD_MOVE_CURSOR_RIGHT Move cursor right without changing display data RAM
_LCD_TURN_ON Turn Lcd display on
_LCD_TURN_OFF Turn Lcd display off
_LCD_SHIFT_LEFT Shift display left without changing display data RAM
_LCD_SHIFT_RIGHT Shift display right without changing display data RAM

Library Example

This example demonstrates how to communicate Lcd via the SPI module, using serial to parallel convertor MCP23S17.

Copy Code To ClipboardCopy Code To Clipboard
program SPI_Lcd

dim text as char[17]

' Port Expander module connections
dim SPExpanderRST as sbit at RC0_bit
    SPExpanderCS  as sbit at RC1_bit
    SPExpanderRST_Direction as sbit at TRISC0_bit
    SPExpanderCS_Direction  as sbit at TRISC1_bit
' End Port Expander module connections

main:

  ANSEL  = 0                             ' Configure AN pins as digital
  ANSELH = 0
  C1ON_bit = 0                           ' Disable comparators
  C2ON_bit = 0
  text = "mikroElektronika"

  ' If Port Expander Library uses SPI1 module
  SPI1_Init()                                   ' Initialize SPI module used with PortExpander

'  ' If Port Expander Library uses SPI2 module
'  SPI2_Init()                                   ' Initialize SPI module used with PortExpander
  SPI_Lcd_Config(0)                     ' Initialize Lcd over SPI interface
  SPI_Lcd_Cmd(_LCD_CLEAR)               ' Clear display
  SPI_Lcd_Cmd(_LCD_CURSOR_OFF)          ' Turn cursor off
  SPI_Lcd_Out(1,6, "mikroE")            ' Print text to Lcd, 1st row, 6th column
  SPI_Lcd_Chr_CP("!")                   ' Append '!'
  SPI_Lcd_Out(2,1, text)                ' Print text to Lcd, 2nd row, 1st column

  ' SPI_Lcd_Out(3,1,"mikroE")          ' For Lcd with more than two rows
  ' SPI_Lcd_Out(4,15,"mikroE")         ' For Lcd with more than two rows
end.

HW Connection

SPI Lcd HW connection

SPI Lcd HW connection

Copyright (c) 2002-2012 mikroElektronika. All rights reserved.
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