Lesson nr.17-Alphanumeric LCD and Push Button

Hardware setup:
In this experiment we will work with alphanumeric LCD and push button.
Communication with LCD will be performed through 4-bits and connections is made as follows: D4 with RB0, D5 with RB1, D6 with RB2, D7 with RB3, RS with RB4 and EN with RB5. The Push button is connected to PORT RA4 (for increment) and PORT RA6 (for decrement). Of course both button have pull-up resistors (4k7).
To make this project more interesting , you can reach from 0000 to 9999 by pressing the button.



Circuit Diagram:
For those who want to build it on their own breadboard or other platform, here is the electronic scheme built in Eagle Cad, free version:

Software:
Here is the C program written for MikroC PRO for PIC 2010 (version v4.15).

/*
'*******************************************************************************
'  Lesson nr.17:
'          Alphanumeric LCD and Push Button.
'  Done by:
'          Aureliu Raducu Macovei, 2010.
'  Description:
'          In this experiment we will work with alphanumeric LCD and push button.
'          Communication with LCD will be performed through 4-bits and connections
'          is made as follows: D4 with RB0, D5 with RB1, D6 with RB2, D7 with RB3;
'                              RS with RB4 and EN with RB5.
'          The Push button is connected to PORT RA4 (for increment) and PORT RA6
'          (for decrement). Of course both button have pull-up resistors (4k7).
'          To make this project more interesting , you can reach from 0000 to 9999 
'          by pressing the button.
'  Test configuration:
'    MCU:                        PIC16F628A
'    Test.Board:                 WB-106 Breadboard 2420 dots
'    SW:                         MikroC PRO for PIC 2010 (version v4.15)
'  Configuration Word
'    Oscillator:                 INTOSC:I/O on RA.6, I/O on RA.7
'    Watchdog Timer:             OFF
'    Power up Timer:             Disabled
'    Master Clear Enable:        Enabled
'    Browun Out Detect:          Enabled
'    Low Voltage Program:        Disabled
'    Data EE Read Protect:       Disabled
'    Code Protect:               OFF
'*******************************************************************************
*/
// LCD module connections
sbit LCD_RS at RB4_bit;                 // LCD_RS assigned to PORT RB4;
sbit LCD_EN at RB5_bit;                 // LCD_EN assigned to PORT RB5;
sbit LCD_D4 at RB0_bit;                 // LCD_D4 assigned to PORT RB0;
sbit LCD_D5 at RB1_bit;                 // LCD_D5 assigned to PORT RB1;
sbit LCD_D6 at RB2_bit;                 // LCD_D6 assigned to PORT RB2;
sbit LCD_D7 at RB3_bit;                 // LCD_D7 assigned to PORT RB3;

sbit LCD_RS_Direction at TRISB4_bit;    // LCD_RS assigned to TRIS B4;
sbit LCD_EN_Direction at TRISB5_bit;    // LCD_EN assigned to TRIS B5;
sbit LCD_D4_Direction at TRISB0_bit;    // LCD_D4 assigned to TRIS B0;
sbit LCD_D5_Direction at TRISB1_bit;    // LCD_D5 assigned to TRIS B1;
sbit LCD_D6_Direction at TRISB2_bit;    // LCD_D6 assigned to TRIS B2;
sbit LCD_D7_Direction at TRISB3_bit;    // LCD_D7 assigned to TRIS B3;
// End LCD module connections

char Message1[]="LCD and Button";       // Message for line1;
unsigned int number = 0;

char *digit = "0000";

void Display_init()   // define display_init;
{                    
 digit[0] = number/1000 + 48;           // thousands digit;
 digit[1] = (number/100)%10 +48;        // hundreds digit;
 digit[2] = (number/10)%10 + 48;        // tens digit;
 digit[3] = number%10 +48;              // unit digit;
 Lcd_Out(2,7,digit);                    // display on LCD from column 2, character 7;
}

void main()                             // main;
{
 CMCON |= 7;                            // turn off analogue comparator and make PORTA to digital I/O;
 TRISA6_bit = 1;                        // make PORT RA6 as input for button;
 TRISA7_bit = 1;                        // make PORT RA7 as input for button;
 PORTA = 0;                             // Turn ON PORTA;
 TRISB = 0;                             // Set PORTB direction to be output;
 PORTB = 0;                             // Turn ON PORTB;

 Lcd_init();                            // LCD Initialization;
 Lcd_cmd(_LCD_CLEAR);                   // Clear LCD;
 Lcd_cmd(_LCD_CURSOR_OFF);              // Cursor mode, off;
 Lcd_out(1,2,Message1);                 // display message1 from column 1, character 3;

 do{
    if(Button(&PORTA,4,1,0)){
                             Delay_ms(200);    // If button is pressed, delay 0,2s and increment "number" with 1;
                             number = number +1;
                             }
    if(Button(&PORTA,6,1,0)){
                             Delay_ms(200);    // If button is pressed, delay 0,2s and decrement "number" with 1;
                             number = number -1;
                             }
    if (number > 9999u)                 // if it's more than 9999 go to 0;
    number = 0;
    display_init();                     // call display_init();
    } while(1);                         // infinite loop;
 }                                      // end.