usart.h

gehe zur Dokumentation dieser Datei

/*  BSD-License:

Copyright (c) 2007 by Nils Springob, nicai-systems, Germany

All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice,
    this list of conditions and the following disclaimer.
  * Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation
    and/or other materials provided with the distribution.
  * Neither the name nicai-systems nor the names of its contributors may be
    used to endorse or promote products derived from this software without
    specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef NIBOBEE_USART_H_
#define NIBOBEE_USART_H_

#include <stdint.h>
#include <avr/pgmspace.h>

#ifdef __cplusplus
extern "C" {
#endif

#define USART_TXBUF_SIZE 16
#define USART_RXBUF_SIZE 8

void usart_setbaudrate(uint16_t baud);

extern uint8_t usart_txbuf[USART_TXBUF_SIZE];
extern uint8_t usart_rxbuf[USART_RXBUF_SIZE];

extern volatile uint8_t usart_txbuf_begin;
extern volatile uint8_t usart_txbuf_end;

extern volatile uint8_t usart_rxbuf_begin;
extern volatile uint8_t usart_rxbuf_end;

void usart_enable();

void usart_disable();


char usart_getchar();


char usart_putchar(char c);


void usart_write(const char * s);


void usart_write_P(PGM_P s);


void usart_send(const char * s, unsigned int len);


void usart_send_P(PGM_P s, unsigned int len);



static inline char usart_rxempty() {
  return usart_rxbuf_begin==usart_rxbuf_end;
}


static inline char usart_txempty() {
  return usart_txbuf_begin==usart_txbuf_end;
}


static inline char usart_rxfull() {
  return usart_rxbuf_end==USART_RXBUF_SIZE;
}


static inline char usart_txfull() {
  return usart_txbuf_end==USART_TXBUF_SIZE;
}


static inline char usart_rxavail() {
  // fn is isr save (order important)!
  int s=(int)usart_rxbuf_end-(int)usart_rxbuf_begin;
  if (usart_rxfull()) return USART_RXBUF_SIZE;  
  return (s<0)?(USART_RXBUF_SIZE+s):s;
}


static inline char usart_txfree() {
  // fn is isr save (order important)!
  int s=(int)usart_txbuf_end-(int)usart_txbuf_begin;
  if (usart_txfull()) return 0;
  return (s<0)?(-s):(USART_TXBUF_SIZE-s);
}


#ifdef __cplusplus
} // extern "C"
#endif

#endif // NIBOBEE_USART_H_