SPI Lcd Library

The mikroPascal 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 :

The library uses the SPI module for communication. The user must initialize the SPI module before using the SPI Lcd Library.
This Library is designed to work with the mikroElektronika's Serial Lcd Adapter Board pinout. See schematic at the bottom of this page for details.

Library Dependency Tree

External dependencies of SPI LcdLibrary

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.

SPI_Lcd_Config

Prototype	procedure SPI_Lcd_Config(DeviceAddress: 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 var SPExpanderCS : sbit at RC1_bit; SPExpanderRST : sbit at RC0_bit; SPExpanderCS_Direction : sbit at TRISC1_bit; SPExpanderRST_Direction : sbit at TRISC_bit; // 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	procedure SPI_Lcd_Out(row: byte; column: byte; var text: 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	procedure SPI_Lcd_Out_CP(var text : 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	procedure SPI_Lcd_Chr(Row : byte; Column : byte; Out_Char : 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	procedure SPI_Lcd_Chr_CP(Out_Char : 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	procedure SPI_Lcd_Cmd(out_char : 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.

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program Spi_Lcd;

var text : string[16];

// Port Expander module connections
var SPExpanderRST : sbit at RC0_bit;
    SPExpanderCS  : sbit at RC1_bit;
    SPExpanderRST_Direction : sbit at TRISC0_bit;
    SPExpanderCS_Direction  : sbit at TRISC1_bit;
// End Port Expander module connections

begin

  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

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