63 lines
1.9 KiB
C
63 lines
1.9 KiB
C
/**
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* (C) Copyright Collin J. Doering 2015
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* File: USART.c
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* Author: Collin J. Doering <collin.doering@rekahsoft.ca>
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* Date: Oct 6, 2015
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*/
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#include <avr/io.h>
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#include "USART.h"
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#include <util/setbaud.h>
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#ifndef BAUD /* if not defined in Makefile... */
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#define BAUD 9600 /* set a safe default baud rate */
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#endif
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void initUSART(void) { /* requires BAUD */
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UBRR0H = UBRRH_VALUE; /* defined in setbaud.h */
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UBRR0L = UBRRL_VALUE;
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#if USE_2X
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UCSR0A |= (1 << U2X0);
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#else
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UCSR0A &= ~(1 << U2X0);
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#endif
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/* Enable USART transmitter/receiver */
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UCSR0B = (1 << TXEN0) | (1 << RXEN0);
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UCSR0C = (1 << UCSZ01) | (1 << UCSZ00); /* 8 data bits, 1 stop bit */
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}
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void transmitByte(uint8_t data) {
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/* Wait for empty transmit buffer */
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loop_until_bit_is_set(UCSR0A, UDRE0);
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UDR0 = data; /* send data */
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}
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void transmitString(const char* data) {
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while (*data != '\0') {
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transmitByte(*data);
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data++;
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}
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}
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uint8_t receiveByte(void) {
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loop_until_bit_is_set(UCSR0A, RXC0); /* Wait for incoming data */
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return UDR0; /* return register value */
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}
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