#include <avr/io.h>
#include <math.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#ifndef F_CPU
	#define F_CPU 16000000L
	#include <util/delay.h> 
#endif
#define UART_UBRR_CALC(BAUD_,FREQ_) ((FREQ_)/((BAUD_)*16L)-1)
#define UART_BAUD_RATE      115200
#define UART_BUFFER            64
#define FREQUENCY 20000L

/////////////////////////////////////////////////////////////////////////////////

uint8_t uart_buffer[UART_BUFFER];
int8_t  uart_count  = 0; 
uint16_t volatile phase0 =0;
/////////////////////////////////////////////////////////////////////////////////

//Interrupts 
ISR(SIG_INPUT_CAPTURE1)
{
	//timer capture	
	phase0 = TCNT1;
}
ISR(SIG_UART_RECV)
{ /* INTERRUPT: receive char from UART and save it the buffer
*/
    if (uart_count < UART_BUFFER) uart_buffer[uart_count++] = UDR;
} 

//
/////////////////////////////////////////////////////////////////////////////////
//Methodes
inline void uart_init(uint8_t tx, uint8_t rx)
{
    uint16_t baudrate;
    baudrate = UART_BAUD_RATE/2;
    UBRRH    = (uint8_t) (UART_UBRR_CALC(baudrate,F_CPU)>>8);
    UBRRL    = (uint8_t) UART_UBRR_CALC(baudrate,F_CPU);
    UCSRA |= (1<<U2X);
    UCSRB |= (1<<RXCIE);
	UCSRC = (1 << URSEL) | (1 << UCSZ1) | (1 << UCSZ0);
    if(tx) UCSRB |= (1<<TXEN);
    if(rx) UCSRB |= (1<<RXEN);
}
void uart_puts(uint8_t *data)
{ /* send string per UART
   */
    while(*data)
    {
        uart_putc(*data);
        data++;
    }
}
void uart_putf(float data)
{ 
	/* send float per UART BUG: unnötige Leerzeichen am Anfang?  */
    uint8_t buffer[7];
    uart_puts(dtostrf(data, 6, 3, buffer));
}
void uart_putc(uint8_t c)
{
    while (!(UCSRA & (1<<UDRE)));
    UDR = c;
}
void uart_puti(uint16_t data)
{
    uint8_t buffer[7];
    uart_puts(utoa(data, buffer, 10));
}
void input_capture_init()
{
	// ICF1 Interrupt free
	TIMSK |= (1<<ICF1);
	//// Timer frequency with 1 Prescaler
	TCCR1B |= (1<<CS10) | (1<<ICNC1);
	TCCR1B &= ~(1<<ICES1);


}
/////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////
//Main programm
int main(void)
{			
    	uart_init(1, 1);
	input_capture_init() ;
	sei();
    while(1) // Unendlich lang wiederholen
    {	
		//wait until PD6 low
		while(!(PIND & (1<<PD6)));
		//timer value initialize, measurement will be started	
		TCNT1 = 0;
		//wit until PD6 high
		while(PIND & (1<<PD6));
		uart_puti(phase2);
		uart_putc('\n');
		uart_putc(13);
    }
}