Lcd Library
The mikroC PRO for dsPIC30/33 and PIC24 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 sbit LCD_RS: |
Register Select line. | sbit LCD_RS at LATD0_bit; |
extern sfr sbit LCD_EN: |
Enable line. | sbit LCD_EN at LATD1_bit; |
extern sfr sbit LCD_D4; |
Data 4 line. | sbit LCD_D4 at LATB0_bit; |
extern sfr sbit LCD_D5; |
Data 5 line. | sbit LCD_D5 at LATB1_bit; |
extern sfr sbit LCD_D6; |
Data 6 line. | sbit LCD_D6 at LATB2_bit; |
extern sfr sbit LCD_D7; |
Data 7 line. | sbit LCD_D7 at LATB3_bit |
extern sfr sbit LCD_RS_Direction; |
Register Select direction pin. | sbit LCD_RS_Direction at TRISD0_bit; |
extern sfr sbit LCD_EN_Direction; |
Enable direction pin. | sbit LCD_EN_Direction at TRISD1_bit; |
extern sfr sbit LCD_D4_Direction; |
Data 4 direction pin. | sbit LCD_D4_Direction at TRISB0_bit; |
extern sfr sbit LCD_D5_Direction; |
Data 5 direction pin. | sbit LCD_D5_Direction at TRISB1_bit; |
extern sfr sbit LCD_D6_Direction; |
Data 6 direction pin. | sbit LCD_D6_Direction at TRISB2_bit; |
extern sfr sbit LCD_D7_Direction; |
Data 7 direction pin. | sbit LCD_D7_Direction at TRISB3_bit; |
Library Routines
Lcd_Init
Prototype |
void Lcd_Init(); |
---|---|
Description |
Initializes Lcd module. |
Parameters |
None. |
Returns |
Nothing. |
Requires |
External dependencies of the library from the top of the page 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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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:
// 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 char txt1[] = "mikroElektronika"; char txt2[] = "EasydsPIC4A"; char txt3[] = "Lcd4bit"; char txt4[] = "example"; char i; // Loop variable void Move_Delay() { // Function used for text moving Delay_ms(500); // You can change the moving speed here } void main(){ ADPCFG = 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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