Lcd Library

The mikroC PRO for PIC32 provides a library for communication with Lcds (with HD44780 compliant controllers) through the 4-bit interface. An example of Lcd connections is given on the schematic at the bottom of this page.

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

Library Dependency Tree

External dependencies of Lcd Library

The following variables must be defined in all projects using Lcd Library :	Description :	Example :
`extern sfr atomic sbit LCD_RS:`	Register Select line.	`sbit LCD_RS at LATD0_bit;`
`extern sfr atomic sbit LCD_EN:`	Enable line.	`sbit LCD_EN at LATD1_bit;`
`extern sfr atomic sbit LCD_D4;`	Data 4 line.	`sbit LCD_D4 at LATB0_bit;`
`extern sfr atomic sbit LCD_D5;`	Data 5 line.	`sbit LCD_D5 at LATB1_bit;`
`extern sfr atomic sbit LCD_D6;`	Data 6 line.	`sbit LCD_D6 at LATB2_bit;`
`extern sfr atomic sbit LCD_D7;`	Data 7 line.	`sbit LCD_D7 at LATB3_bit`
`extern sfr atomic sbit LCD_RS_Direction;`	Register Select direction pin.	`sbit LCD_RS_Direction at TRISD0_bit;`
`extern sfr atomic sbit LCD_EN_Direction;`	Enable direction pin.	`sbit LCD_EN_Direction at TRISD1_bit;`
`extern sfr atomic sbit LCD_D4_Direction;`	Data 4 direction pin.	`sbit LCD_D4_Direction at TRISB0_bit;`
`extern sfr atomic sbit LCD_D5_Direction;`	Data 5 direction pin.	`sbit LCD_D5_Direction at TRISB1_bit;`
`extern sfr atomic sbit LCD_D6_Direction;`	Data 6 direction pin.	`sbit LCD_D6_Direction at TRISB2_bit;`
`extern sfr atomic sbit LCD_D7_Direction;`	Data 7 direction pin.	`sbit LCD_D7_Direction at TRISB3_bit;`

Lcd_Init

Prototype	void Lcd_Init();
Description	Initializes Lcd module.
Parameters	None.
Returns	Nothing.
Requires	Global variables: `LCD_RS:` Register Select (data/instruction) signal pin `LCD_EN:` Enable signal pin `LCD_D4:` Data bit 4 `LCD_D5:` Data bit 5 `LCD_D6:` Data bit 6 `LCD_D7:` Data bit 7 `LCD_RS_Direction:` Direction of the Register Select pin `LCD_EN_Direction:` Direction of the Enable signal pin `LCD_D4_Direction:` Direction of the Data 4 pin `LCD_D5_Direction:` Direction of the Data 5 pin `LCD_D6_Direction:` Direction of the Data 6 pin `LCD_D7_Direction:` Direction of the Data 7 pin must be defined before using this function.
Example	// Lcd module connections sbit LCD_RS at LATD0_bit; sbit LCD_EN at LATD1_bit; sbit LCD_D4 at LATB0_bit; sbit LCD_D5 at LATB1_bit; sbit LCD_D6 at LATB2_bit; sbit LCD_D7 at LATB3_bit; sbit LCD_RS_Direction at TRISD0_bit; sbit LCD_EN_Direction at TRISD1_bit; sbit LCD_D4_Direction at TRISB0_bit; sbit LCD_D5_Direction at TRISB1_bit; sbit LCD_D6_Direction at TRISB2_bit; sbit LCD_D7_Direction at TRISB3_bit; // End Lcd module connections ... Lcd_Init();
Notes	None.

Lcd_Out

Prototype	void Lcd_Out(unsigned int row, unsigned int column, char *text);
Description	Prints text on 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	The Lcd module needs to be initialized. See Lcd_Init routine.
Example	// Write text "Hello!" on Lcd starting from row 1, column 3: Lcd_Out(1, 3, "Hello!");
Notes	None.

Lcd_Out_Cp

Prototype	void Lcd_Out_Cp(char *text);
Returns	Nothing.
Description	Prints text on Lcd at current cursor position. Both string variables and literals can be passed as a text.
Parameters	`text:` text to be written
Requires	The Lcd module needs to be initialized. See Lcd_Init routine.
Example	// Write text "Here!" at current cursor position: Lcd_Out_Cp("Here!");
Notes	None.

Lcd_Chr

Prototype	void Lcd_Chr(unsigned int row, unsigned int column, char out_char);
Description	Prints character on Lcd at specified position. Both variables and literals can be passed as a character.
Parameters	`row:` writing position row number `column:` writing position column number `out_char:` character to be written
Returns	Nothing.
Requires	The Lcd module needs to be initialized. See Lcd_Init routine.
Example	// Write character "i" at row 2, column 3: Lcd_Chr(2, 3, 'i');
Notes	None.

Lcd_Chr_Cp

Prototype	void Lcd_Chr_Cp(char out_char);
Description	Prints character on Lcd at current cursor position. Both variables and literals can be passed as a character.
Parameters	`out_char:` character to be written
Returns	Nothing.
Requires	The Lcd module needs to be initialized. See Lcd_Init routine.
Example	// Write character "e" at current cursor position: Lcd_Chr_Cp('e');
Notes	None.

Lcd_Cmd

Prototype	void Lcd_Cmd(char out_char);
Description	Sends command to Lcd.
Parameters	`out_char:` command to be sent
Returns	Nothing.
Requires	The Lcd module needs to be initialized. See Lcd_Init table.
Example	// Clear Lcd display: Lcd_Cmd(_LCD_CLEAR);
Notes	Predefined constants can be passed to the function, see Available Lcd Commands.

Available Lcd Commands

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

The following code demonstrates usage of the Lcd Library routines:

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// LCD module connections
sbit LCD_RS at LATB2_bit;
sbit LCD_EN at LATB3_bit;
sbit LCD_D4 at LATB4_bit;
sbit LCD_D5 at LATB5_bit;
sbit LCD_D6 at LATB6_bit;
sbit LCD_D7 at LATB7_bit;

sbit LCD_RS_Direction at TRISB2_bit;
sbit LCD_EN_Direction at TRISB3_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;
// End LCD module connections

char txt1[] = "mikroElektronika";    
char txt2[] = "LV32MX v6";
char txt3[] = "Lcd4bit";
char txt4[] = "example";

char i;                              // Loop variable

void Move_Delay() {                  // Function used for text moving
  Delay_ms(750);                     // You can change the moving speed here
}

void main(){
  CHECON = 0x32;
  AD1PCFG  = 0xFFFF;                 // Configure AN pins as digital I/O

  Lcd_Init();                        // Initialize LCD

  Lcd_Cmd(_LCD_CLEAR);               // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off
  Lcd_Out(1,6,txt3);                 // Write text in first row

  Lcd_Out(2,6,txt4);                 // Write text in second row
  Delay_ms(2000);
  Lcd_Cmd(_LCD_CLEAR);               // Clear display

  Lcd_Out(1,1,txt1);                 // Write text in first row
  Lcd_Out(2,5,txt2);                 // Write text in second row

  Delay_ms(2000);

  // Moving text
  for(i=0; i<4; i++) {               // Move text to the right 4 times
    Lcd_Cmd(_LCD_SHIFT_RIGHT);
    Move_Delay();
  }

  while(1) {                         // Endless loop
    for(i=0; i<8; i++) {             // Move text to the left 7 times
      Lcd_Cmd(_LCD_SHIFT_LEFT);
      Move_Delay();
    }

    for(i=0; i<8; i++) {             // Move text to the right 7 times
      Lcd_Cmd(_LCD_SHIFT_RIGHT);
      Move_Delay();
    }
  }
}

Lcd HW connection

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