//---------------------------------------------------------------------------------------
// Programm Nr.: 11
// Content     : ADC (single conversion) on pressing a key + output 10-bit on LCD
//             : two int->ascii for lcd routines with leading zero subpression
// Author      : digital AG Halle
// Date        : 27.07.2008
// System      : ATmega8-16PU - Dai Hoc Hue Development Board
//---------------------------------------------------------------------------------------

//--included Files-----------------------------------------------------------------------

#include <avr/io.h>
#include <util/delay.h>

//--declarations-------------------------------------------------------------------------

#ifndef F_CPU
#define F_CPU 8000000	//CPU frequency = 8 MHz
#endif


#define LCD_PORT      PORTD
#define LCD_DDR       DDRD
#define LCD_RS        0x04
#define LCD_EN        5

void lcd_enable(void);	  	    	//setup communication to the lcd
void lcd_data(unsigned char temp1);	//send a byte to the lcd
void lcd_clear(void);			//erase all displayed signs
void lcd_init(void);			//initialise lcd
void set_cursor(uint8_t x, uint8_t y);	//set cursor to position x,y
void lcd_string(char *data);		//send a string to the lcd

void messure();								  //ADC routine to catch a 10-bit value
void output(uint8_t proc);					  //general output routine
void processing1(uint16_t value,uint8_t row); //lcd output routine
void processing2(uint16_t value,uint8_t row); //lcd output routine with leading zero subpression

uint8_t KEYS;
uint8_t KEYS_OLD;
uint8_t proced;

uint16_t result;		//16 bit value for the 10-Bit result of the ADC messure
uint32_t voltage; 		//32 bit calculation variable


//--MAIN PROGRAMM------------------------------------------------------------------------

int main(void)
{

	//--INITIALISATION---------------------------------------------------------------

	//ADC_INIT:
		ADMUX |= (1<<REFS0);	// for left adjust use: | (1<<ADLAR);
		//ext. Vref = AVcc, right adjusted result, channel 0
		ADCSRA |=  (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0) | (1<<ADEN); 
		//prescaler = 128 (rate = 62,5 kHz), single conversion
	
	//PORT_INIT:
		DDRC=224;	//Port C key inputs and bit0 analog channel 0 input
		PORTC=30;	//Pullup (keys and analog input)
		DDRD=255; 	//Port D: all bits defined as output (for the status LEDs)
		PORTD=255; 	//all LEDs off

	//--PROGRAMM CODE BEFORE MAIN LOOP (USED JUST ONE TIME)--------------------------
		
		lcd_init();
		KEYS_OLD=PINC;

	//--MAIN LOOP--------------------------------------------------------------------
	
	while(1)
	{
	 	KEYS=PINC;

		if (KEYS_OLD!=KEYS) 
		{
			//mask  = 1110 0010 = 226 dec.
			if ((KEYS&226)==!(0x02))	//if key 1 was pressed
			{

				messure();				

			//calculation of voltage
			//AVref= 5.00 V
				voltage = (result*49)/100; //interger (no digits behind the dot)
											//5.00V /1024 =4.9 mV
				proced=1;
				output(proced);
			
			}
			//mask  = 1110 0100 = 228 dec.
			if ((KEYS&228)==!(0x04))	//if key 2 was pressed
			{

				messure();				

			//calculation of voltage
			//AVref= 5.00 V
				voltage = (result*49)/100; //interger (no digits behind the dot)
											//5.00V /1024 =4.9 mV
				proced=2;
				output(proced);
			
			}
		}
		KEYS_OLD=KEYS;
	}
	return 0;
}

//--MAIN PROGRAMM END--------------------------------------------------------------------

//--EXTERNAL ROUTINES (FOR THE LCD)------------------------------------------------------

void messure()
{
		ADCSRA |= (1<<ADSC);
				//ADC enable
			while(ADCSRA & (1<<ADSC)); //wait for first complete messure cycle
						   //(first cycle is a dummy cycle)
        
			while(!(ADCSRA & 0x10));// wait for ADIF flag '1'
						// (end of messuring)
			

		// 	    *** ALLWAYS READ ADCL REGISTER FIRST !!! ***
		// *** READ ALLWAYS BOTH REGISTERS OR THE ADC WILL HANG UP !!! ***

				result = ADCL;			// read ADCL register
				result += (ADCH<<8);	// read ADCH register and add the 2 bits to result
										// result is 0...1023
		//stop the internal ADC after the messure
			ADCSRA ^= (1<<ADSC);	
}

void output(uint8_t proc)
{
			set_cursor(0,1);		//cursor at 1st row, digit 0
			lcd_string("result = ");//print out on LCD

			if (proc==1){
				processing1(result,1);	//send result as ascii to the LCD into row 1
				processing1(voltage,2);//row 2
			}
			else{
				processing2(result,1);	//send result as ascii to the LCD into row 1
				processing2(voltage,2);//row 2
			}
	
			lcd_string(" V");			//unit of voltage

}

void processing1(uint16_t value,uint8_t row)
{
uint8_t offset = 0;

	//creates from the result-value a ascii-value for displaying

		set_cursor(9,row);
			lcd_data(0x30+(value/10000));		//digit 10000
		set_cursor(10,row);
			lcd_data(0x30+((value/1000)%10));	//digit  1000
     		set_cursor(11,row);
			lcd_data(0x30+((value/100)%10));	//digit   100
			if(row==2){
				offset = 1;						//shift last 2 digits 1 right
				set_cursor(12,row);	
				lcd_data(0x2c);					//komma
			}
		set_cursor(12,(row+offset));
			lcd_data(0x30+((value/10)%10));		//digit    10
		set_cursor(13,(row+offset));
			lcd_data(0x30+(value%10));			//digit     1	

}

void processing2(uint16_t value,uint8_t row)  //advanced output routine without leading zeros
{
uint8_t offset = 0;
uint8_t calc = 0;

		set_cursor(9,row);
			calc=(value/10000);
			if (calc==0)
				lcd_data(0x20);					//0x20 ascii = space
			else
				lcd_data(0x30+(value/10000));	//digit 10000

		set_cursor(10,row);
			calc=((value/1000)%10);
			if ((calc==0)&&((value/10000)==0))
				lcd_data(0x20);					//0x20 ascii = space
			else
				lcd_data(0x30+((value/1000)%10));//digit  1000

     		set_cursor(11,row);					//the last zero has to stay allways
			lcd_data(0x30+((value/100)%10));	//digit   100
			if(row==2){
				offset = 1;						//shift last 2 digits 1 right
				set_cursor(12,row);	
				lcd_data(0x2c);					//komma
			}
		set_cursor(12,(row+offset));
			lcd_data(0x30+((value/10)%10));		//digit    10
		set_cursor(13,(row+offset));
			lcd_data(0x30+(value%10));			//digit     1	

}

void lcd_data(unsigned char temp1) //send a data byte to the lcd
{
   unsigned char temp2 = temp1;
 
   LCD_PORT |= (1<<LCD_RS);        // set line RS to 1 
 
   temp1 = temp1 >> 4;
   temp1 = temp1 & 0x0F;
   LCD_PORT &= 0xF0;
   LCD_PORT |= temp1;               // set
   lcd_enable();
 
   temp2 = temp2 & 0x0F;
   LCD_PORT &= 0xF0;
   LCD_PORT |= temp2;               // set
   lcd_enable();
   
   _delay_us(42);
}

void lcd_command(unsigned char temp1) //send a command to the lcd
{
   unsigned char temp2 = temp1;
 
   LCD_PORT &= ~(1<<LCD_RS);        // set RS to 0 
 
   temp1 = temp1 >> 4;              // get high nibble
   temp1 = temp1 & 0x0F;            // mask
   LCD_PORT &= 0xF0;
   LCD_PORT |= temp1;               // set
   lcd_enable();
 
   temp2 = temp2 & 0x0F;            // get and mask low nibble
   LCD_PORT &= 0xF0;
   LCD_PORT |= temp2;               // set
   lcd_enable();
   
   _delay_us(42);
}

void lcd_enable(void)		//send the enable puls to the lcd
{
   LCD_PORT |= (1<<LCD_EN);
    _delay_us(1);                   
   LCD_PORT &= ~(1<<LCD_EN);
}

void lcd_init(void)		//initialize the lcd
{
   LCD_DDR = LCD_DDR | 0x0F | (1<<LCD_RS) | (1<<LCD_EN);   // Port auf Ausgang schalten
 
   //for intitialization do this 3 times !
 
   _delay_ms(15);
   LCD_PORT &= 0xF0;
   LCD_PORT |= 0x03;            
   LCD_PORT &= ~(1<<LCD_RS);      // RS to 0
   lcd_enable();
 
   _delay_ms(5);
   lcd_enable();
 
   _delay_ms(1);
   lcd_enable();
 
   //activate 4-bit-mode
   LCD_PORT &= 0xF0;
   LCD_PORT |= 0x02;
   lcd_enable();
 
   //mode: 4-bit; 2 rows; character of 5x7 dots
   lcd_command(0x28);
    
   //lcd on; cursor off; no blinking
   lcd_command(0x0C); 
 
   //increment; no scrolling
   lcd_command(0x06);
 
   lcd_clear();
}
 
void lcd_clear(void) 		//cleares the full lcd content
{
   lcd_command(0x01);
   _delay_ms(5);
}
 
void lcd_home(void)		//set the cursor to x0,y0
{
   lcd_command(0x02);
   _delay_ms(5);
}
 
void set_cursor(uint8_t x, uint8_t y) 	//set cursor to another position
					//x=0-20 (colum); y=1,2 (row)
{
  switch (y) {
    case 1: lcd_command(0x80+0x00+x); break;    // 1st row
    case 2: lcd_command(0x80+0x40+x); break;    // 2nd row
  }
}
 
void lcd_string(char *data)	//send a string to the lcd
{
    while(*data) {
        lcd_data(*data);
        data++;
    }
}

//--PROGRAMM END-------------------------------------------------------------------------