mirror of
https://github.com/binary-kitchen/doorlockd
synced 2024-10-31 22:47:05 +01:00
54 lines
936 B
C
54 lines
936 B
C
#include <stddef.h>
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#include <avr/interrupt.h>
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#include <avr/io.h>
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#include "uart.h"
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#define UBRR_VAL ((F_CPU+BAUD*8)/(BAUD*16)-1)
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#define BAUD_REAL (F_CPU/(16*(UBRR_VAL+1)))
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#define BAUD_ERROR ((BAUD_REAL*1000)/BAUD)
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#if ((BAUD_ERROR<990) || (BAUD_ERROR>1010))
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#error Choose another crystal. Baud error too high.
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#endif
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static void (*recv_handler)(unsigned char c) = NULL;
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ISR(USART_RX_vect)
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{
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cli();
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if(recv_handler)
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recv_handler(UDR);
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sei();
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}
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void uart_init()
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{
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// Enable receive and transmit
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UCSRB = (1<<RXEN)|(1<<TXEN)|(1<<RXCIE);
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// Asynchronous mode, 8N1
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UCSRC = (1<<UCSZ1)|(1<<UCSZ0);
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UBRRH = UBRR_VAL >> 8;
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UBRRL = UBRR_VAL & 0xFF;
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}
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void uart_set_recv_handler(void (*handler)(unsigned char c))
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{
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recv_handler = handler;
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}
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void uart_putc(const char c)
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{
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while ( !(UCSRA & (1<<UDRE)) );
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UDR = (const unsigned char)c;
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}
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void uart_puts(const char* str)
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{
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do {
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uart_putc(*str);
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} while(*++str);
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}
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