Rev 2039 |
Blame |
Compare with Previous |
Last modification |
View Log
| RSS feed
#include <avr/io.h>
#include <avr/interrupt.h>
#include "uart1.h"
#include "ubx.h"
#define USART1_BAUD 57600
/****************************************************************/
/* 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) (F_CPU / (8 * USART1_BAUD) - 1);
// disable all interrupts before reconfiguration
cli();
// disable RX-Interrupt, disable TX-Interrupt, disable DRE-Interrupt
UCSR1B &= ~ ((1 << RXCIE1) | (1 << TXCIE1) | (1 << UDRIE1));
// set direction of RXD1 and TXD1 pins
// set RXD1 (PD2) as an input pin, set TXD1 (PD3) as an output pin
PORTD |= (1 << PORTD2) | (1 << PORTD3);
DDRD &= ~(1 << DDD2);
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, no parity, 1 stop bit
UCSR1C &= ~((1 << UMSEL11) | (1 << UMSEL10) | (1 << UPM11) | (1 << UPM10) | (1 << USBS1));
// 8-bit
UCSR1B &= ~(1 << UCSZ12);
UCSR1C |= (1 << UCSZ11) | (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 data register empty ISR */
/****************************************************************/
/*ISR(USART1_UDRE_vect) {
}
*/
/****************************************************************/
/* USART1 transmitter ISR */
/****************************************************************/
/*ISR(USART1_TX_vect) {
}
*/
/****************************************************************/
/* USART1 receiver ISR */
/****************************************************************/
ISR(USART1_RX_vect) {
ubx_parser(UDR1); // get data byte and put it into the ubx protocol parser
}