LCD.c

#include "defines.h"
#include <inttypes.h>
#include "tiva.h"
#include "Timer.h"
#include <string.h>
#define RS 0x10  //Pin 4 in Port A
#define RW 0x08  //Pin 3 in Port A
#define EN 0x04  //Pin 2 in Port A


/* LCD Control: this function will be called every time you want to give the LCD a command */
void LCD_CMD(unsigned char signal){
		GPIO_PORTA_DATA_R = 0x00; 								//Set RS,RW to 0 to Enable write
		SysTick_Wait(8000);
		GPIO_PORTA_DATA_R |= 0x04; 								//Enable write data
		SysTick_Wait(8000);
		GPIO_PORTB_DATA_R = signal; 							//Set Data of PortB
		SysTick_Wait(8000);
		GPIO_PORTA_DATA_R = 0x00; 								//To Disable changes for LCD
	
		/*Commands of code 0000 --> 0111 Requires 2ms to be sure they are executed
		Commands above that Requires 40 microsec to be sure they are executed*/
		if(signal < 4) SysTick_Wait(160000); 			// 2ms
		else SysTick_Wait(3200); 									// 40 micro sec
}
/* this function will be used every time we want to show something on LCD */
void LCD_Clear_Display(void){
	LCD_CMD(0x01);             									//Remove Chars
	LCD_CMD(0x02);             									//Return cursor to zero position
}

void LCD_Init(void){

    /*Enable PortA bits 2-4 for Rs Rw Enable*/
    GPIO_PORTA_CR_R |= 0x1C;									//enable changes for PA2-4
		GPIO_PORTA_AMSEL_R &= ~0x1C;							// analog disable for PA2-4
		GPIO_PORTA_PCTL_R &= ~0x000FFF00;					//use PA2-4 as GPIO
		GPIO_PORTA_AFSEL_R &= ~0x1C;							//disable alternate function of PA2-4
		GPIO_PORTA_DIR_R |= 0x1C;									// use PA2-4 as output					
		GPIO_PORTA_DEN_R |= 0x1C;									//digital enable for PA2-4
		//Enable port B bits 0-7 for
		GPIO_PORTB_CR_R |= 0xFF;									//repeat
		GPIO_PORTB_AMSEL_R &= ~0xFF;
		GPIO_PORTB_PCTL_R &= ~0xFFFFFFFF;
		GPIO_PORTB_AFSEL_R &= ~0xFF;
		GPIO_PORTB_DIR_R |= 0xFF;						
		GPIO_PORTB_DEN_R |= 0xFF;	

		LCD_CMD(0x38);           									// Enable 8 bit mode
		LCD_CMD(0x0F);           									// Turn on Display
		LCD_Clear_Display();     									// calling this function in order to clear the LCD at beginning
}

/* LCD_Write a function that writes character on LCD */
void LCD_Write(unsigned char Data){
	GPIO_PORTA_DATA_R = 0x10; 								  //which means RS=1, RW=0, EN=0 to control that the entered is data not command
	SysTick_Wait(8000);
	GPIO_PORTA_DATA_R |= 0x04; 									//Enable write data
	SysTick_Wait(8000);
	GPIO_PORTB_DATA_R = Data;  									//LCD has the data entered on port B
	SysTick_Wait(8000);
	GPIO_PORTA_DATA_R = 0x00;										//To Disable changes for LCD
	SysTick_Wait(8000);
	LCD_CMD(0x06);             									//Increment from left to right
}

/*LCD_Show function to write the whole string on LCD */
void LCD_Show(char *str){   									// write a string on LCD
  int l=strlen(str);        									// l = string length
  int i=0;                    								//itterator
  while(i<l){
		LCD_Write(str[i]);       								  // call the function LCD_Write 
		i++; 											    						// increment the itterator
    }
}