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/***************************************************************************
* Copyright (C) 11/2014 by Olaf Rempel *
* razzor@kopf-tisch.de *
* *
* 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; version 2 of the License, *
* *
* 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, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include <avr/io.h>
#include <avr/interrupt.h>
#include "target.h"
#define UART_CALC_BAUDRATE(baudRate) ((uint32_t)(F_CPU) / ((uint32_t)(baudRate)*16) -1)
/* *********************************************************************** */
static uint8_t uart_rxbuf[UART_RXBUF_SIZE];
static uint8_t uart_txbuf[UART_TXBUF_SIZE];
static volatile uint8_t uart_rx_idx[2];
static volatile uint8_t uart_tx_idx[2];
#define UART_IDX_IN 0
#define UART_IDX_OUT 1
/* *********************************************************************** */
ISR(USART_RX_vect)
{
uint8_t idx = uart_rx_idx[UART_IDX_IN];
uart_rxbuf[idx++] = UDR0;
uart_rx_idx[UART_IDX_IN] = idx % sizeof(uart_rxbuf);
} /* USART_RX_vect */
ISR(USART_UDRE_vect)
{
/* tx buffer empty? */
if (uart_tx_idx[UART_IDX_IN] != uart_tx_idx[UART_IDX_OUT])
{
/* send next byte */
uint8_t idx = uart_tx_idx[UART_IDX_OUT];
UDR0 = uart_txbuf[idx++];
uart_tx_idx[UART_IDX_OUT] = idx % sizeof(uart_txbuf);
}
else
{
/* disable tx-interrupt */
UCSR0B &= ~(1<<UDRIE0);
}
} /* USART_UDRE_vect */
void uart_init(void)
{
/* set baudrate */
UBRR0H = (UART_CALC_BAUDRATE(BAUDRATE)>>8) & 0xFF;
UBRR0L = (UART_CALC_BAUDRATE(BAUDRATE) & 0xFF);
/* USART: rx/tx enable, 8n1 */
UCSR0B = (1<<TXEN0) | (1<<RXEN0) | (1<<RXCIE0);
UCSR0C = (1<<UCSZ01) | (1<<UCSZ00);
} /* uart_init */
void uart_putc(uint8_t data)
{
uint8_t idx = uart_tx_idx[UART_IDX_IN];
uart_txbuf[idx++] = data;
uart_tx_idx[UART_IDX_IN] = idx % sizeof(uart_txbuf);
/* enable tx-interrupt */
UCSR0B |= (1<<UDRIE0);
} /* uart_putc */
uint8_t uart_getc(void)
{
while (uart_rx_idx[UART_IDX_IN] == uart_rx_idx[UART_IDX_OUT]);
/* send next byte */
uint8_t idx = uart_rx_idx[UART_IDX_OUT];
uint8_t result = uart_rxbuf[idx++];
uart_rx_idx[UART_IDX_OUT] = idx % sizeof(uart_rxbuf);
return result;
} /* uart_getc */
uint8_t uart_rx_count(void)
{
return (uart_rx_idx[UART_IDX_IN] - uart_rx_idx[UART_IDX_OUT]) % sizeof(uart_rxbuf);
} /* uart_check */
void uart_putstr(const char *str)
{
while (*str)
{
uart_putc((uint8_t)(*str++));
}
} /* uart_putstr */
static uint8_t bin2hex(uint8_t data)
{
return data + ((data < 0x0A) ? '0' : ('A' - 0x0A));
} /* bin2hex */
static uint8_t hex2bin(uint8_t data)
{
if (data >= '0' && data <= '9')
{
return (data - '0');
}
else
{
data &= ~(0x20);
if (data >= 'A' && data <= 'F')
{
return (data - 'A' + 0x0A);
}
}
return 0x00;
} /* hex2bin */
void uart_put_hex(uint8_t data)
{
uart_putc(bin2hex(data >> 4));
uart_putc(bin2hex(data & 0x0F));
} /* uart_hex */
uint8_t uart_get_hex(void)
{
uint8_t result;
result = hex2bin(uart_getc()) << 4;
result |= hex2bin(uart_getc());
return result;
} /* uart_hex */