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#include <avr/io.h>
#include <avr/interrupt.h>

#include "main.h"
#include "uart1.h"
#include "ubx.h"


/****************************************************************/
/*              Initialization of the USART1                    */
/****************************************************************/
void USART1_Init (void)
{
        // USART1 Control and Status Register A, B, C and baud rate register
        uint8_t sreg = SREG;
        uint16_t ubrr = (uint16_t) ((uint32_t) SYSCLK/(8 * USART1_BAUD) - 1);

        // disable all interrupts before reconfiguration
        cli();

        // disable RX-Interrupt
        UCSR1B &= ~(1 << RXCIE1);
        // disable TX-Interrupt
        UCSR1B &= ~(1 << TXCIE1);
        // disable DRE-Interrupt
        UCSR1B &= ~(1 << UDRIE1);

        // set direction of RXD1 and TXD1 pins
        // set RXD1 (PD2) as an input pin
        PORTD |= (1 << PORTD2);
        DDRD &= ~(1 << DDD2);

        // set TXD1 (PD3) as an output pin
        PORTD |= (1 << PORTD3);
        DDRD  |= (1 << DDD3);

        // USART0 Baud Rate Register
        // set clock divider
        UBRR1H = (uint8_t)(ubrr>>8);
        UBRR1L = (uint8_t)ubrr;

        // enable double speed operation
        UCSR1A |= (1 << U2X1);
        // enable receiver and transmitter
        UCSR1B = (1 << TXEN1) | (1 << RXEN1);
        // set asynchronous mode
        UCSR1C &= ~(1 << UMSEL11);
        UCSR1C &= ~(1 << UMSEL10);
        // no parity
        UCSR1C &= ~(1 << UPM11);
        UCSR1C &= ~(1 << UPM10);
        // 1 stop bit
        UCSR1C &= ~(1 << USBS1);
        // 8-bit
        UCSR1B &= ~(1 << UCSZ12);
        UCSR1C |=  (1 << UCSZ11);
        UCSR1C |=  (1 << UCSZ10);

        // flush receive buffer explicit
        while ( UCSR1A & (1<<RXC1) ) UDR1;

        // enable interrupts at the end
        // enable RX-Interrupt
        UCSR1B |= (1 << RXCIE1);
        // enable TX-Interrupt
        UCSR1B |= (1 << TXCIE1);
        // enable DRE interrupt
        //UCSR1B |= (1 << UDRIE1);


        // restore global interrupt flags
    SREG = sreg;

}

/****************************************************************/
/*               USART1 transmitter ISR                         */
/****************************************************************/
/*ISR(USART1_TX_vect)
{

}
*/
/****************************************************************/
/*               USART1 receiver ISR                            */
/****************************************************************/
ISR(USART1_RX_vect)
{
        uint8_t c;
        c = UDR1; // get data byte

        UBX_Parser(c); // and put it into the ubx protocol parser

}