/*  Name     : main.c
 *  Purpose  : Source code for UART Interfacing with AT89C52.
 *  Author   : Gemicates
 *  Date     : 2017-06-21
 *  Website  : www.gemicates.org
 *  Revision : none
 */
#include <regx52.h>
#include <string.h>

#define lcd P2

sbit rs=P1^0;
sbit rw=P1^1;
sbit e=P1^2;

// LCD FUNCTIONS
			void lcddata(char t);     
			void lcdstring( char *l);
			void cmd(unsigned char);
			void com();

// UART FUNCTIONS
			void init();
			void tdata(unsigned char);
			unsigned char rdata(void);

//DELAY FUNCTION
			void delay(unsigned char);

//MAIN FUNCTION//
			void main()
				{
					unsigned int i,j;
					unsigned char c,*d;
					d="gemicates";                                                // Tranamitted Value
					j=strlen(d);
							P1=0x00;
							P2=0x00;
					init();				                              // UART intialization
					com();				                              // LCD intialization
							cmd(0x80);
							lcdstring("TRANSMITTED CHAR");                // LCD string Print  
                                                                                                      // CHARCTER TRANSMISSION LOOP
							cmd(0xc4);				
									for(i=0;i<j;i++)
									{
										tdata(d[i]);
										lcddata(d[i]);
									}
									delay(1000);
							cmd(0x01);
							cmd(0x82);
							lcdstring("RECEIVED CHAR");                   // LCD string Print 
							cmd(0xc7);
									                              // CHARCTER RECEIVE LOOP
									while(1)  
									{
									c=rdata();
									lcddata(c);
									cmd(0xc7);
									}
				}

//SUB FUNCTIONS//

void delay(unsigned char t)	                                                                      // Delay Function
{
	unsigned int i,j;
	for(i=0;i<t;i++)
	for(j=0;j<1275;j++);
}

void init() 		                                                                              // UART INITIALIZATION
{
	TMOD=0x20;
	TH1=0xFD;
	SCON=0x50;
	TR1=1;
}

void tdata(unsigned char t)                                                                           // DATA Transmission
{
	SBUF=t;
	while(TI==0);
	TI=0;
}

unsigned char rdata(void)	                                                                      // DATA Receive
{
	unsigned char d;
	d=SBUF;
	while(RI==0);
	RI=0;
	return d;
}
  
void lcddata(char t)                                                                                  // LCD Data Function
{
	rs=1;
	lcd=t;	
	rw=0;
	e=1;
	delay(1);
	e=0;
}


void cmd(unsigned char c)	                                                                      // LCD Command Function
{
	lcd=c;
	rs=0;
	rw=0;
	e=1;
	delay(1);
	e=0;
}

void com() 	                                                                                      // LCD Decleration Function				
{
	cmd(0x38);
	delay(10);
	cmd(0x0c);
	delay(10);
	cmd(0x01);
	delay(10);
	cmd(0x80);
	delay(10);
}

void lcdstring(char *l) 	                                                                      // LCD String Function 
{
	while(*l !=0)
	{
		lcddata(*l++);
	}
}