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soft_uart.c
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soft_uart.c
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/*
* uart.c Copyright (C) 2015 Ron Pedde <ron@pedde.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <inttypes.h>
#include <stdarg.h>
#include <avr/io.h>
#include <util/delay.h>
#include "util.h"
#include "hardware.h"
#include "soft_uart.h"
void uart_init(void) {
SETBIT(UART_SOFT_DDR, UART_SOFT_PIN); /* out */
SETBIT(UART_SOFT_PORT, UART_SOFT_PIN); /* high */
}
void uart_send_char(uint8_t byte) {
uint8_t rack;
CLEARBIT(UART_SOFT_PORT, UART_SOFT_PIN); /* low */
_delay_us(UART_SOFT_DELAY_US);
for(rack=0; rack<8; rack++) {
if(byte & 1)
SETBIT(UART_SOFT_PORT, UART_SOFT_PIN);
else
CLEARBIT(UART_SOFT_PORT, UART_SOFT_PIN);
byte >>= 1;
_delay_us(UART_SOFT_DELAY_US);
}
SETBIT(UART_SOFT_PORT, UART_SOFT_PIN);
_delay_us(UART_SOFT_DELAY_US);
}
void uart_send_string(char *str) {
while(*str)
uart_send_char((uint8_t) *str++);
}
uint8_t _hex_nibble(uint8_t nibble) {
if(nibble < 10)
return 0x30 + nibble;
return 0x41 + (nibble - 10);
}
void uart_print_hex_byte(uint8_t byte) {
uart_send_char(_hex_nibble(byte >> 4));
uart_send_char(_hex_nibble(byte & 0x0F));
}
void uart_print_hex_word(uint16_t word) {
uart_print_hex_byte((uint8_t)(word >> 8));
uart_print_hex_byte((uint8_t)(word & 0x00FF));
}