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/************************************************************************
Title: Interrupt UART library with receive/transmit circular buffers
Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury
File: $Id: uart.h,v 1.8.2.1 2007/07/01 11:14:38 peter Exp $
Software: AVR-GCC 4.1, AVR Libc 1.4
Hardware: any AVR with built-in UART, tested on AT90S8515 & ATmega8 at 4 Mhz
License: GNU General Public License
Usage: see Doxygen manual
LICENSE:
Copyright (C) 2006 Peter Fleury
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 2 of the License, or
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.
************************************************************************/
//
// @defgroup pfleury_uart UART Library
// @code #include <uart.h> @endcode
//
// @brief Interrupt UART library using the built-in UART with transmit and receive circular buffers.
//
// This library can be used to transmit and receive data through the built in UART.
//
// An interrupt is generated when the UART has finished transmitting or
// receiving a byte. The interrupt handling routines use circular buffers
// for buffering received and transmitted data.
//
// The UART_RX_BUFFER_SIZE and UART_TX_BUFFER_SIZE constants define
// the size of the circular buffers in bytes. Note that these constants must be a power of 2.
// You may need to adapt this constants to your target and your application by adding
// CDEFS += -DUART_RX_BUFFER_SIZE=nn -DUART_RX_BUFFER_SIZE=nn to your Makefile.
//
// @note Based on Atmel Application Note AVR306
// @author Peter Fleury pfleury@gmx.ch http://jump.to/fleury
//
#ifndef UART_H
#define UART_H
#if (__GNUC__ * 100 + __GNUC_MINOR__) < 304
#error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !"
#endif
// constants and macros
// @brief UART Baudrate Expression
// @param xtalcpu system clock in Mhz, e.g. 4000000L for 4Mhz
// @param baudrate baudrate in bps, e.g. 1200, 2400, 9600
//
#define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/((baudRate)*16l)-1)
// @brief UART Baudrate Expression for ATmega double speed mode
// @param xtalcpu system clock in Mhz, e.g. 4000000L for 4Mhz
// @param baudrate baudrate in bps, e.g. 1200, 2400, 9600
//
#define UART_BAUD_SELECT_DOUBLE_SPEED(baudRate,xtalCpu) (((xtalCpu)/((baudRate)*8l)-1)|0x8000)
// Size of the circular receive buffer, must be power of 2
#ifndef UART_RX_BUFFER_SIZE
#define UART_RX_BUFFER_SIZE 32
#endif
// Size of the circular transmit buffer, must be power of 2
#ifndef UART_TX_BUFFER_SIZE
#define UART_TX_BUFFER_SIZE 32
#endif
// test if the size of the circular buffers fits into SRAM
#if ( (UART_RX_BUFFER_SIZE+UART_TX_BUFFER_SIZE) >= (RAMEND-0x60 ) )
#error "size of UART_RX_BUFFER_SIZE + UART_TX_BUFFER_SIZE larger than size of SRAM"
#endif
// high byte error return code of uart_getc()
#define UART_FRAME_ERROR 0x0800 // Framing Error by UART
#define UART_OVERRUN_ERROR 0x0400 // Overrun condition by UART
#define UART_BUFFER_OVERFLOW 0x0200 // receive ringbuffer overflow
#define UART_NO_DATA 0x0100 // no receive data available
//
// function prototypes
//
//
// @brief Initialize UART and set baudrate
// @param baudrate Specify baudrate using macro UART_BAUD_SELECT()
// @return none
//
extern void uart_init(unsigned int baudrate);
//
// @brief Get received byte from ringbuffer
//
// Returns in the lower byte the received character and in the
// higher byte the last receive error.
// UART_NO_DATA is returned when no data is available.
//
// @param void
// @return lower byte: received byte from ringbuffer
// @return higher byte: last receive status
// - \b 0 successfully received data from UART
// - \b UART_NO_DATA
// <br>no receive data available
// - \b UART_BUFFER_OVERFLOW
// <br>Receive ringbuffer overflow.
// We are not reading the receive buffer fast enough,
// one or more received character have been dropped
// - \b UART_OVERRUN_ERROR
// <br>Overrun condition by UART.
// A character already present in the UART UDR register was
// not read by the interrupt handler before the next character arrived,
// one or more received characters have been dropped.
// - \b UART_FRAME_ERROR
// <br>Framing Error by UART
//
extern unsigned int uart_getc(void);
//
// @brief Put byte to ringbuffer for transmitting via UART
// @param data byte to be transmitted
// @return none
//
// @brief Initialize USART1 (only available on selected ATmegas) @see uart_init
extern void uart1_init(unsigned int baudrate);
// @brief Get received byte of USART1 from ringbuffer. (only available on selected ATmega) @see uart_getc
extern unsigned int uart1_getc(void);
// @brief Put byte to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_putc
//extern void uart1_putc(unsigned char data);
extern int uart1_putc(unsigned char data);
// @brief Put string to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts
extern void uart1_puts(const char *s );
// @brief Put string from program memory to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts_p
extern void uart1_puts_p(const char *s );
// @brief Macro to automatically put a string constant into program memory
#define uart1_puts_P(__s) uart1_puts_p(PSTR(__s))
extern char *utoa1(char* buffer, const unsigned int size, unsigned int value);
#endif // UART_H