// Khai bao cac file header
#include	<AT89X52.H>
#include	<Kit8051.h>

// Khai bao cac bien toan cuc
unsigned char code string1[] = "8051 Starter Kit";
unsigned char code string2[] = "Dien ap = ";
unsigned char voltage,digit1,digit2;

// Khai bao cac ham
void InitSystem(void);
void Delay(unsigned int n);
void DelayShort(void);
void InitLCD(void);
void WriteCommand(unsigned char command);
void WriteCharacter(unsigned char character);
void WriteLCD(unsigned char x);
void SendString2LCD(unsigned char code *p);
void DisplayText(void);
void DisplayVoltage(void);
void Convert();
void Calculate();

// Dinh nghia cac ham
void InitSystem(void)
{
	// Cam LCD
	LCD_E = 0;
	// Sang den backlight
	LCD_BL = 0;
	// Tre de LCD tu khoi tao ben trong (it nhat 15ms)
	Delay(100);
	// Tat den backlight
	LCD_BL = 1;
	InitLCD();
}
void Delay(unsigned int n)
{
	unsigned int i,j;
	for(i=0;i<n;i++)
		for(j=0;j<100;j++);
}
void DelayShort(void)
{
	unsigned char i;
	for(i=0;i<10;i++);
}
void InitLCD(void)
{
	WriteCommand(0x30);
	WriteCommand(0x30);
	WriteCommand(0x30);
	
	// 8 bit, 2 lines, font 5x7
	WriteCommand(0x38);
	// Display on, hide cursor
	WriteCommand(0x0C);

	// Xoa man hinh
	WriteCommand(0x01);
}
void DisplayText(void)
{
	// Dich con tro den dau dong thu nhat
	WriteCommand(0x80);
	SendString2LCD(string1);
	// Dich con tro den dau dong thu hai
	WriteCommand(0xC1);
	SendString2LCD(string2);
	// Dich con tro den vi tri don vi do
	WriteCommand(0xCE);
	WriteCharacter('V');
}
void WriteLCD(unsigned char x)
{
	LCD_RW = 0;
	LCD_DATA = x;

	LCD_E = 1;
	LCD_E = 0;
	Delay(5);
}
void WriteCommand(unsigned char command)
{
	LCD_RS = 0;
	WriteLCD(command);
}
void WriteCharacter(unsigned char character)
{
	LCD_RS = 1;
	WriteLCD(character);
}
void SendString2LCD(unsigned char code *p)
{
	unsigned char i=0;
	while(p[i]!=0)
	{
		WriteCharacter(p[i]);
		i++;
		Delay(50);
	}
}
void Convert(void)
{
	// Ra lenh chuyen doi
	ADC_RD = 1;
	ADC_CS = 0;
	DelayShort();
	ADC_WR = 0;
	DelayShort();
	ADC_WR = 1;
	DelayShort();
	ADC_CS = 1;

	// Cho chuyen doi xong
//	Delay(10);
	while(ADC_DONE==1);
	// Chuyen Port thanh cong vao de chuan bi doc du lieu
	ADC_DATA = 0xFF;
	ADC_CS = 0;
	DelayShort();
	ADC_RD = 0;
	DelayShort();
	// Doc du lieu vao
	voltage = ADC_DATA;
	ADC_RD = 1;
	DelayShort();
	ADC_CS = 1;
}
void Calculate(void)
{
	unsigned int temp;
	temp = (voltage*10);
	temp = temp/52;
	// tinh ra dien ap tu gia tri ADC dua ve
	// tach phan nguyen va phan thap phan
	digit1 = (unsigned char) (temp/10);
	digit2 = (unsigned char)(temp%10);
	// chuyen sang ma ASCII
	digit1 = digit1 + 0x30;
	digit2 = digit2 + 0x30;
}
void DisplayVoltage(void)
{
	// Dua con tro den vi tri can hien thi
	WriteCommand(0xCB);
	WriteCharacter(digit1);
	WriteCharacter('.');
	WriteCharacter(digit2);
}
// Chuong trinh chinh
void main(void)
{
	// Khoi tao he thong
	InitSystem();
	DisplayText();
	// Vong lap vo tan
	while(1)
	{
		Convert();
		Calculate();
		DisplayVoltage();
	}
}