SPI Lcd Library

The mikroPascal PRO for PIC32 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

procedure SPI_Lcd_Config(DeviceAddress : byte);

Description

Initializes the Lcd module via SPI interface.

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

Nothing.

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.


The SPI module needs to be initialized. See SPIx_Init and SPIx_Init_Advanced routines.

Example
// Port Expander module connections
var SPExpanderRST : sbit at LATF0_bit;
var SPExpanderCS  : sbit at LATF1_bit;
var SPExpanderRST_Direction : sbit at TRISF0_bit;
var SPExpanderCS_Direction  : sbit at TRISF1_bit;
// End Port Expander module connections

// If Port Expander Library uses SPI1 module
SPI1_Init();                           // Initialize SPI module used with PortExpander
SPI_Lcd_Config(0);                     // initialize Lcd over SPI interface
Notes

None.

SPI_Lcd_Out

Prototype

procedure SPI_Lcd_Out(row, column : byte; var text : string);

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
Returns

Nothing.

Requires

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

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

None.

SPI_Lcd_Out_Cp

Prototype

procedure SPI_Lcd_Out_CP(var text : string); // write text at current pos

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
Returns

Nothing.

Requires

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

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

None.

SPI_Lcd_Chr

Prototype

procedure SPI_Lcd_Chr(Row, Column, Out_Char : byte);

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
Returns

Nothing.

Requires

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

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

None.

SPI_Lcd_Chr_Cp

Prototype

procedure SPI_Lcd_Chr_CP(Out_Char : byte);

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
Returns

Nothing.

Requires

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

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

None.

SPI_Lcd_Cmd

Prototype

procedure SPI_Lcd_Cmd(out_char : byte);

Description

Sends command to Lcd.

Parameters
  • out_char: command to be sent
Returns

Nothing.

Requires

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

Example
// Clear Lcd display:
SPI_Lcd_Cmd(_LCD_CLEAR);
Notes

Predefined constants can be passed to the routine, see Available SPI Lcd Commands.

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

Default Pin Configuration

Use SPI_Lcd_Init for default pin settings (see the first figure below).

Copy Code To ClipboardCopy Code To Clipboard
program Spi_Lcd;

var text : array[16] of char;
var counter : byte;

// Port Expander module connections
var SPExpanderRST : sbit at LATD8_bit;
    SPExpanderCS  : sbit at LATD9_bit;
    SPExpanderRST_Direction : sbit at TRISD8_bit;
    SPExpanderCS_Direction  : sbit at TRISD9_bit;
// End Port Expander module connections

procedure Move_Delay();                  // Function used for text moving
  begin
    Delay_ms(500);                       // You can change the moving speed here
  end;
  
  begin
    text := 'mikroElektronika';
    CHECON := 0x32;
    AD1PCFG := 0xFFFF;                                       // Configure AN pins as digital

    // If Port Expander Library uses SPI2 module
    // Initialize SPI module used with PortExpander
    SPI2_Init_Advanced(_SPI_MASTER,_SPI_8_BIT, 4, _SPI_SS_DISABLE,_SPI_DATA_SAMPLE_MIDDLE,_SPI_CLK_IDLE_LOW,_SPI_ACTIVE_2_IDLE);
    
    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

    Delay_ms(2000);

    // Moving text
    for counter := 0 to 3 do             // Move text to the right 4 times
      begin
        Spi_Lcd_Cmd(_LCD_SHIFT_RIGHT);
        Move_Delay();
      end;

    while TRUE do                              // Endless loop
      begin
        for counter := 0 to 6 do               // Move text to the left 7 times
          begin
            Spi_Lcd_Cmd(_LCD_SHIFT_LEFT);
            Move_Delay();
          end;

        for counter := 0 to 6 do               // Move text to the right 7 times
          begin
            Spi_Lcd_Cmd(_LCD_SHIFT_RIGHT);
            Move_Delay();
          end;

      end;
  end.

Lcd HW connection by default initialization (using SPI_Lcd_Init)

Lcd HW connection by default initialization (using SPI_Lcd_Init)

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