1
0
mirror of https://github.com/binary-kitchen/doorlockd synced 2024-11-16 20:19:13 +01:00
doorlockd-mirror/avr-code/uart.c

54 lines
936 B
C
Raw Normal View History

2015-09-16 22:58:00 +02:00
#include <stddef.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include "uart.h"
#define UBRR_VAL ((F_CPU+BAUD*8)/(BAUD*16)-1)
#define BAUD_REAL (F_CPU/(16*(UBRR_VAL+1)))
#define BAUD_ERROR ((BAUD_REAL*1000)/BAUD)
#if ((BAUD_ERROR<990) || (BAUD_ERROR>1010))
#error Choose another crystal. Baud error too high.
#endif
static void (*recv_handler)(unsigned char c) = NULL;
ISR(USART_RX_vect)
{
cli();
if(recv_handler)
recv_handler(UDR);
sei();
}
void uart_init()
{
// Enable receive and transmit
UCSRB = (1<<RXEN)|(1<<TXEN)|(1<<RXCIE);
// Asynchronous mode, 8N1
UCSRC = (1<<UCSZ1)|(1<<UCSZ0);
UBRRH = UBRR_VAL >> 8;
UBRRL = UBRR_VAL & 0xFF;
}
void uart_set_recv_handler(void (*handler)(unsigned char c))
{
recv_handler = handler;
}
void uart_putc(const char c)
{
while ( !(UCSRA & (1<<UDRE)) );
UDR = (const unsigned char)c;
}
void uart_puts(const char* str)
{
do {
uart_putc(*str);
} while(*++str);
}