/*  Name     : main.c
 *  Purpose  : Source code for LDR Interfacing with AT89C52.
 *  Author   : Gemicates
 *  Date     : 2017-06-15
 *  Website  : www.gemicates.org
 *  Revision : None
 */
 

 //Program to check the working of LDR using LCD on its output port.
#include <REGX52.H>

#define lcd P0						// LCD data pins
sbit rs = P1^5;  					// register select pin
sbit rw= P1^6;  					// read write pin
sbit e = P1^7;  					// enable pin

#define input P2  				        // Input port to read the values of ADC
#define output P0  				        // Output port, connected to LED's.

sbit wr= P1^1;  					// Write pin. It is used to start the conversion. 
sbit rd= P1^0;  					// Read pin. It is used to extract the data from internal register to the output pins of ADC.
sbit intr= P1^2;  				        // Interrupt pin. This is used to indicate the end of conversion. It goes low when conversion is complete.

unsigned char number,value,v1,v2,v3;

void delay(unsigned int msec )                          // The delay function provides delay in msec.
{
	int i,j ;
	for(i=0;i<msec;i++)
  for(j=0;j<1275; j++);
}

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 initialization function
{
cmd(0x38);
delay(10);
cmd(0x0c);
delay(10);
cmd(0x01);
delay(10);
}

void string(char *d)		                        // lcd string print function
{
while(*d !=0)
{
	lcddata(*d++);
}
}

void BCD()						// BCD conversion function
{
	number=output;
	value=number;
	v1=value/100+0x30;
	v2=value%100/10+0x30;
	v3=value%10+0x30;
	string("value :");
	cmd(0x88);
	lcddata(v1);
	lcddata(v2);
	lcddata(v3);
	
//	value=number*19.62;
//	v1=value/100+0x30;
//	v2=value%100/10+0x30;
//	v3=value%10+0x30;
//      cmd(0xc0);
//	
//	string("volts :");
//	cmd(0xc8);
//	lcddata(v1);
//	lcddata('.');
//	lcddata(v2);
//	lcddata(v3);
}


void adc()  					        // Function to read the values from ADC0804 and display on the LCD.
{
	rd=1;     
	wr=0;     
	delay(1);
	wr=1;
	while(intr==1);
	rd=0;
	output=input;
	BCD();
	delay(1);
	intr=1;
}


void main()
{
  input=0xff;  					        // Declare port 2 as input port.       
	while(1)
	{
		com();
    adc();
		delay(100);
  }
}