AVR Uart RS232/454 libc AVR系列串口开发库

串口是单片机领域最常见的数据传输接口，我们几乎可以在任何单片机上找到一个或者更多的硬件串行接口（Uart）。单片机开发中，会经常使用到串口，而编写相应的开发库将会大大提高开发效率，省去诸多麻烦。

Peter Fleury编写了AVR系列串口程序编程接口库。Tim Sharpe在Fleury的基础上作了更多的改进。详见：http://beaststwo.org/avr-uart/index.shtml

但是该编程库在使用的时候有若干问题，所以我做了一些修改。改动如下：

1。波特率计算：注释部分为Tim Sharpe原来的代码

#define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/(baudRate)/16-1)
//#define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/((baudRate)*16l)-1)

#define UART_BAUD_SELECT_DOUBLE_SPEED(baudRate,xtalCpu) (((xtalCpu)/(baudRate)/8-1)|0x8000)
//#define UART_BAUD_SELECT_DOUBLE_SPEED(baudRate,xtalCpu) (((xtalCpu)/((baudRate)*8l)-1)|0x8000)

2.增加一些阻塞接口：

/**
 * @brief   block 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  input char
 */
extern unsigned char uart_ngetc(void);

/**
 *  @brief   block Put byte to ringbuffer for transmitting via UART
 *  @param   data byte to be transmitted
 *  @return  none
 */
extern void uart_nputc(unsigned char data);

/**
 *  @brief   block Put string to ringbuffer for transmitting via UART
 *
 *  The string is buffered by the uart library in a circular buffer
 *  and one character at a time is transmitted to the UART using interrupts.
 *  Blocks if it can not write the whole string into the circular buffer.
 *
 *  @param   s string to be transmitted
 *  @return  none
 */
extern void uart_nputs(const char *s );

根据Tim的网页，该库支持的芯片型号有：

Supported AVR Models (in alphabetical order):

• AT90S2313
• AT90S2333
• AT90S4414
• AT90S4433
• AT90S4434
• AT90S8515
• AT90S8535
• ATmega8
• ATmega16
• ATmega32
• ATmega48
• ATmega48P New!
• ATmega64
• ATmega88
• ATmega88P New!
• ATmega103
• ATmega128
• ATmega162
• ATmega163
• ATmega164P
• ATmega168
• ATmega168P New!
• ATmega169
• ATmega323
• ATmega324P
• ATmega325
• ATmega328P New!
• ATmega329
• ATmega640
• ATmega644
• ATmega644P
• ATmega645
• ATmega649
• ATmega1280
• ATmega2560
• ATmega3250
• ATmega3290
• ATmega6450
• ATmega6490
• ATmega8515
• ATmega8535
• ATtiny2313

Happy MCU-ing!

改修后代码：

uart.h：

#ifndef UART_H#define UART_H/************************************************************************Title:    Interrupt UART library with receive/transmit circular buffersAuthor:   Peter Fleury <[e-mail]>   http://jump.to/fleuryFile:     $Id: uart.h,v 1.8.2.1 2007/07/01 11:14:38 peter Exp $Software: AVR-GCC 4.1, AVR Libc 1.4Hardware: any AVR with built-in UART, tested on AT90S8515 & ATmega8 at 4 MhzLicense:  GNU General Public LicenseUsage:    see Doxygen manualLICENSE:    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.************************************************************************//************************************************************************uart_available, uart_flush, uart1_available, and uart1_flush functionswere adapted from the Arduino HardwareSerial.h library by Tim Sharpe on11 Jan 2009.  The license info for HardwareSerial.h is as follows:  HardwareSerial.h - Hardware serial library for Wiring  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.  This library is free software; you can redistribute it and/or  modify it under the terms of the GNU Lesser General Public  License as published by the Free Software Foundation; either  version 2.1 of the License, or (at your option) any later version.  This library 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  Lesser General Public License for more details.  You should have received a copy of the GNU Lesser General Public  License along with this library; if not, write to the Free Software  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA************************************************************************//************************************************************************Changelog for modifications made by Tim Sharpe, starting with the current  library version on his Web site as of 05/01/2009.Date        Description=========================================================================05/12/2009  Added Arduino-style available() and flush() functions for both                        supported UARTs.  Really wanted to keep them out of the library, so                        that it would be as close as possible to Peter Fleury's original                        library, but has scoping issues accessing internal variables from                        another program.  Go C!************************************************************************//** *  @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 [e-mail]  http://jump.to/fleury *//**@{*/#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)/16-1)//#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)/8-1)|0x8000)//#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   non-block 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  input char */extern unsigned char uart_ngetc(void);/** *  @brief   Put byte to ringbuffer for transmitting via UART *  @param   data byte to be transmitted *  @return  none */extern void uart_putc(unsigned char data);/** *  @brief   non-block Put byte to ringbuffer for transmitting via UART *  @param   data byte to be transmitted *  @return  none */extern void uart_nputc(unsigned char data);/** *  @brief   Put string to ringbuffer for transmitting via UART * *  The string is buffered by the uart library in a circular buffer *  and one character at a time is transmitted to the UART using interrupts. *  Blocks if it can not write the whole string into the circular buffer. * *  @param   s string to be transmitted *  @return  none */extern void uart_puts(const char *s );/** *  @brief   non-block Put string to ringbuffer for transmitting via UART * *  The string is buffered by the uart library in a circular buffer *  and one character at a time is transmitted to the UART using interrupts. *  Blocks if it can not write the whole string into the circular buffer. * *  @param   s string to be transmitted *  @return  none */extern void uart_nputs(const char *s );/** * @brief    Put string from program memory to ringbuffer for transmitting via UART. * * The string is buffered by the uart library in a circular buffer * and one character at a time is transmitted to the UART using interrupts. * Blocks if it can not write the whole string into the circular buffer. * * @param    s program memory string to be transmitted * @return   none * @see      uart_puts_P */extern void uart_puts_p(const char *s );/** * @brief    Macro to automatically put a string constant into program memory */#define uart_puts_P(__s)       uart_puts_p(PSTR(__s))/** *  @brief   Return number of bytes waiting in the receive buffer *  @param   none *  @return  bytes waiting in the receive buffer */extern int uart_available(void);/** *  @brief   Flush bytes waiting in receive buffer *  @param   none *  @return  none */extern void uart_flush(void);/** @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);/** @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))/** @brief   Return number of bytes waiting in the receive buffer */extern int uart1_available(void);/** @brief   Flush bytes waiting in receive buffer */extern void uart1_flush(void);/**@}*/#endif // UART_H

uart.c:

/*************************************************************************Title:    Interrupt UART library with receive/transmit circular buffersAuthor:   Peter Fleury <[e-mail]>   http://jump.to/fleuryFile:     $Id: uart.c,v 1.6.2.1 2007/07/01 11:14:38 peter Exp $Software: AVR-GCC 4.1, AVR Libc 1.4.6 or higherHardware: any AVR with built-in UART,License:  GNU General Public LicenseDESCRIPTION:    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 variables define    the buffer size in bytes. Note that these variables must be a    power of 2.USAGE:    Refere to the header file uart.h for a description of the routines.    See also example test_uart.c.NOTES:    Based on Atmel Application Note AVR306LICENSE:    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.*************************************************************************//************************************************************************uart_available, uart_flush, uart1_available, and uart1_flush functionswere adapted from the Arduino HardwareSerial.h library by Tim Sharpe on11 Jan 2009.  The license info for HardwareSerial.h is as follows: HardwareSerial.cpp - Hardware serial library for Wiring  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.  This library is free software; you can redistribute it and/or  modify it under the terms of the GNU Lesser General Public  License as published by the Free Software Foundation; either  version 2.1 of the License, or (at your option) any later version.  This library 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  Lesser General Public License for more details.  You should have received a copy of the GNU Lesser General Public  License along with this library; if not, write to the Free Software  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA  Modified 23 November 2006 by David A. Mellis************************************************************************//************************************************************************Changelog for modifications made by Tim Sharpe, starting with the current  library version on his Web site as of 05/01/2009.Date        Description=========================================================================05/11/2009  Changed all existing UARTx_RECEIVE_INTERRUPT and UARTx_TRANSMIT_INTERRUPT              macros to use the "_vect" format introduced in AVR-Libc                          v1.4.0.  Had to split the 3290 and 6490 out of their existing                          macro due to an inconsistency in the UART0_RECEIVE_INTERRUPT                          vector name (seems like a typo: USART_RX_vect for the 3290/6490                          vice USART0_RX_vect for the others in the macro).                        Verified all existing macro register names against the device                          header files in AVR-Libc v1.6.6 to catch any inconsistencies.05/12/2009  Added support for 48P, 88P, 168P, and 328P by adding them to the               existing 48/88/168 macro.                        Added Arduino-style available() and flush() functions for both                        supported UARTs.  Really wanted to keep them out of the library, so                        that it would be as close as possible to Peter Fleury's original                        library, but has scoping issues accessing internal variables from                        another program.  Go C!05/13/2009  Changed Interrupt Service Routine label from the old "SIGNAL" to               the "ISR" format introduced in AVR-Libc v1.4.0.************************************************************************/#include <avr/io.h>#include <avr/interrupt.h>#include <avr/pgmspace.h>#include "uart.h"/* *  constants and macros *//* size of RX/TX buffers */#define UART_RX_BUFFER_MASK ( UART_RX_BUFFER_SIZE - 1)#define UART_TX_BUFFER_MASK ( UART_TX_BUFFER_SIZE - 1)#if ( UART_RX_BUFFER_SIZE & UART_RX_BUFFER_MASK )#error RX buffer size is not a power of 2#endif#if ( UART_TX_BUFFER_SIZE & UART_TX_BUFFER_MASK )#error TX buffer size is not a power of 2#endif#if defined(__AVR_AT90S2313__) \ || defined(__AVR_AT90S4414__) || defined(__AVR_AT90S4434__) \ || defined(__AVR_AT90S8515__) || defined(__AVR_AT90S8535__) \ || defined(__AVR_ATmega103__) /* old AVR classic or ATmega103 with one UART */ #define AT90_UART #define UART0_RECEIVE_INTERRUPT   UART_RX_vect #define UART0_TRANSMIT_INTERRUPT  UART_UDRE_vect #define UART0_STATUS   USR #define UART0_CONTROL  UCR #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif defined(__AVR_AT90S2333__) || defined(__AVR_AT90S4433__) /* old AVR classic with one UART */ #define AT90_UART #define UART0_RECEIVE_INTERRUPT   UART_RX_vect #define UART0_TRANSMIT_INTERRUPT  UART_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif  defined(__AVR_ATmega8__)  || defined(__AVR_ATmega16__) || defined(__AVR_ATmega32__) \  || defined(__AVR_ATmega323__)  /* ATmega with one USART */ #define ATMEGA_USART #define UART0_RECEIVE_INTERRUPT   USART_RXC_vect #define UART0_TRANSMIT_INTERRUPT  USART_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif  defined(__AVR_ATmega8515__) || defined(__AVR_ATmega8535__)  /* ATmega with one USART */ #define ATMEGA_USART #define UART0_RECEIVE_INTERRUPT   USART_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif defined(__AVR_ATmega163__)  /* ATmega163 with one UART */ #define ATMEGA_UART #define UART0_RECEIVE_INTERRUPT   UART_RX_vect #define UART0_TRANSMIT_INTERRUPT  UART_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif defined(__AVR_ATmega162__) /* ATmega with two USART */ #define ATMEGA_USART0 #define ATMEGA_USART1 #define UART0_RECEIVE_INTERRUPT   USART0_RXC_vect #define UART1_RECEIVE_INTERRUPT   USART1_RXC_vect #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect #define UART1_TRANSMIT_INTERRUPT  USART1_UDRE_vect #define UART0_STATUS   UCSR0A #define UART0_CONTROL  UCSR0B #define UART0_DATA     UDR0 #define UART0_UDRIE    UDRIE0 #define UART1_STATUS   UCSR1A#define UART1_CONTROL  UCSR1B #define UART1_DATA     UDR1 #define UART1_UDRIE    UDRIE1#elif defined(__AVR_ATmega64__) || defined(__AVR_ATmega128__) /* ATmega with two USART */ #define ATMEGA_USART0 #define ATMEGA_USART1 #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect #define UART1_RECEIVE_INTERRUPT   USART1_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect #define UART1_TRANSMIT_INTERRUPT  USART1_UDRE_vect #define UART0_STATUS   UCSR0A #define UART0_CONTROL  UCSR0B #define UART0_DATA     UDR0 #define UART0_UDRIE    UDRIE0 #define UART1_STATUS   UCSR1A #define UART1_CONTROL  UCSR1B #define UART1_DATA     UDR1 #define UART1_UDRIE    UDRIE1#elif defined(__AVR_ATmega161__) /* ATmega with UART */ #error "AVR ATmega161 currently not supported by this libaray !"#elif defined(__AVR_ATmega169__) /* ATmega with one USART */ #define ATMEGA_USART #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif defined(__AVR_ATmega48__) ||defined(__AVR_ATmega88__) || defined(__AVR_ATmega168__) || \      defined(__AVR_ATmega48P__) ||defined(__AVR_ATmega88P__) || defined(__AVR_ATmega168P__) || \      defined(__AVR_ATmega328P__) /* TLS-Added 48P/88P/168P/328P */ /* ATmega with one USART */ #define ATMEGA_USART0 #define UART0_RECEIVE_INTERRUPT   USART_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART_UDRE_vect #define UART0_STATUS   UCSR0A #define UART0_CONTROL  UCSR0B #define UART0_DATA     UDR0 #define UART0_UDRIE    UDRIE0#elif defined(__AVR_ATtiny2313__) #define ATMEGA_USART #define UART0_RECEIVE_INTERRUPT   USART_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART_UDRE_vect #define UART0_STATUS   UCSRA #define UART0_CONTROL  UCSRB #define UART0_DATA     UDR #define UART0_UDRIE    UDRIE#elif defined(__AVR_ATmega329__) ||\      defined(__AVR_ATmega649__) ||\      defined(__AVR_ATmega325__) ||defined(__AVR_ATmega3250__) ||\      defined(__AVR_ATmega645__) ||defined(__AVR_ATmega6450__)  /* ATmega with one USART */  #define ATMEGA_USART0  #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect  #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect  #define UART0_STATUS   UCSR0A  #define UART0_CONTROL  UCSR0B  #define UART0_DATA     UDR0  #define UART0_UDRIE    UDRIE0#elif defined(__AVR_ATmega3290__) ||\      defined(__AVR_ATmega6490__) ||  /* TLS-Separated these two from the previous group because of inconsistency in the USART_RX */  /* ATmega with one USART */  #define ATMEGA_USART0  #define UART0_RECEIVE_INTERRUPT   USART_RX_vect  #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect  #define UART0_STATUS   UCSR0A  #define UART0_CONTROL  UCSR0B  #define UART0_DATA     UDR0  #define UART0_UDRIE    UDRIE0#elif defined(__AVR_ATmega2560__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega640__)/* ATmega with two USART */  #define ATMEGA_USART0  #define ATMEGA_USART1  #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect  #define UART1_RECEIVE_INTERRUPT   USART0_UDRE_vect  #define UART0_TRANSMIT_INTERRUPT  USART1_RX_vect  #define UART1_TRANSMIT_INTERRUPT  USART1_UDRE_vect  #define UART0_STATUS   UCSR0A  #define UART0_CONTROL  UCSR0B  #define UART0_DATA     UDR0  #define UART0_UDRIE    UDRIE0#define UART1_STATUS   UCSR1A  #define UART1_CONTROL  UCSR1B  #define UART1_DATA     UDR1  #define UART1_UDRIE    UDRIE1#elif defined(__AVR_ATmega644__) /* ATmega with one USART */ #define ATMEGA_USART0 #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect #define UART0_TRANSMIT_INTERRUPT  USART0_UDRE_vect #define UART0_STATUS   UCSR0A #define UART0_CONTROL  UCSR0B #define UART0_DATA     UDR0 #define UART0_UDRIE    UDRIE0#elif defined(__AVR_ATmega164P__) || defined(__AVR_ATmega324P__) || defined(__AVR_ATmega644P__) /* ATmega with two USART */ #define ATMEGA_USART0 #define ATMEGA_USART1 #define UART0_RECEIVE_INTERRUPT   USART0_RX_vect #define UART1_RECEIVE_INTERRUPT   USART0_UDRE_vect #define UART0_TRANSMIT_INTERRUPT  USART1_RX_vect #define UART1_TRANSMIT_INTERRUPT  USART1_UDRE_vect #define UART0_STATUS   UCSR0A #define UART0_CONTROL  UCSR0B #define UART0_DATA     UDR0 #define UART0_UDRIE    UDRIE0 #define UART1_STATUS   UCSR1A #define UART1_CONTROL  UCSR1B #define UART1_DATA     UDR1 #define UART1_UDRIE    UDRIE1#else #error "no UART definition for MCU available"#endif/* *  module global variables */static volatile unsigned char UART_TxBuf[UART_TX_BUFFER_SIZE];static volatile unsigned char UART_RxBuf[UART_RX_BUFFER_SIZE];static volatile unsigned char UART_TxHead;static volatile unsigned char UART_TxTail;static volatile unsigned char UART_RxHead;static volatile unsigned char UART_RxTail;static volatile unsigned char UART_LastRxError;#if defined( ATMEGA_USART1 )static volatile unsigned char UART1_TxBuf[UART_TX_BUFFER_SIZE];static volatile unsigned char UART1_RxBuf[UART_RX_BUFFER_SIZE];static volatile unsigned char UART1_TxHead;static volatile unsigned char UART1_TxTail;static volatile unsigned char UART1_RxHead;static volatile unsigned char UART1_RxTail;static volatile unsigned char UART1_LastRxError;#endifISR(UART0_RECEIVE_INTERRUPT)/*************************************************************************Function: UART Receive Complete interruptPurpose:  called when the UART has received a character**************************************************************************/{    unsigned char tmphead;    unsigned char data;    unsigned char usr;    unsigned char lastRxError;    /* read UART status register and UART data register */    usr  = UART0_STATUS;    data = UART0_DATA;    /* */#if defined( AT90_UART )    lastRxError = (usr & (_BV(FE)|_BV(DOR)) );#elif defined( ATMEGA_USART )    lastRxError = (usr & (_BV(FE)|_BV(DOR)) );#elif defined( ATMEGA_USART0 )    lastRxError = (usr & (_BV(FE0)|_BV(DOR0)) );#elif defined ( ATMEGA_UART )    lastRxError = (usr & (_BV(FE)|_BV(DOR)) );#endif    /* calculate buffer index */    tmphead = ( UART_RxHead + 1) & UART_RX_BUFFER_MASK;    if ( tmphead == UART_RxTail ) {        /* error: receive buffer overflow */        lastRxError = UART_BUFFER_OVERFLOW >> 8;    }else{        /* store new index */        UART_RxHead = tmphead;        /* store received data in buffer */        UART_RxBuf[tmphead] = data;    }    UART_LastRxError = lastRxError;}ISR(UART0_TRANSMIT_INTERRUPT)/*************************************************************************Function: UART Data Register Empty interruptPurpose:  called when the UART is ready to transmit the next byte**************************************************************************/{    unsigned char tmptail;    if ( UART_TxHead != UART_TxTail) {        /* calculate and store new buffer index */        tmptail = (UART_TxTail + 1) & UART_TX_BUFFER_MASK;        UART_TxTail = tmptail;        /* get one byte from buffer and write it to UART */        UART0_DATA = UART_TxBuf[tmptail];  /* start transmission */    }else{        /* tx buffer empty, disable UDRE interrupt */        UART0_CONTROL &= ~_BV(UART0_UDRIE);    }}/*************************************************************************Function: uart_init()Purpose:  initialize UART and set baudrateInput:    baudrate using macro UART_BAUD_SELECT()Returns:  none**************************************************************************/void uart_init(unsigned int baudrate){    UART_TxHead = 0;    UART_TxTail = 0;    UART_RxHead = 0;    UART_RxTail = 0;#if defined( AT90_UART )    /* set baud rate */    UBRR = (unsigned char)baudrate;    /* enable UART receiver and transmmitter and receive complete interrupt */    UART0_CONTROL = _BV(RXCIE)|_BV(RXEN)|_BV(TXEN);#elif defined (ATMEGA_USART)    /* Set baud rate */    if ( baudrate & 0x8000 )    {         UART0_STATUS = (1<<U2X);  //Enable 2x speed         baudrate &= ~0x8000;    }    UBRRH = (unsigned char)(baudrate>>8);    UBRRL = (unsigned char) baudrate;    /* Enable USART receiver and transmitter and receive complete interrupt */    UART0_CONTROL = _BV(RXCIE)|(1<<RXEN)|(1<<TXEN);    /* Set frame format: asynchronous, 8data, no parity, 1stop bit */    #ifdef URSEL    UCSRC = (1<<URSEL)|(3<<UCSZ0);    #else    UCSRC = (3<<UCSZ0);    #endif#elif defined (ATMEGA_USART0 )    /* Set baud rate */    if ( baudrate & 0x8000 )    {                UART0_STATUS = (1<<U2X0);  //Enable 2x speed                baudrate &= ~0x8000;        }    UBRR0H = (unsigned char)(baudrate>>8);    UBRR0L = (unsigned char) baudrate;    /* Enable USART receiver and transmitter and receive complete interrupt */    UART0_CONTROL = _BV(RXCIE0)|(1<<RXEN0)|(1<<TXEN0);    /* Set frame format: asynchronous, 8data, no parity, 1stop bit */    #ifdef URSEL0    UCSR0C = (1<<URSEL0)|(3<<UCSZ00);    #else    UCSR0C = (3<<UCSZ00);    #endif#elif defined ( ATMEGA_UART )    /* set baud rate */    if ( baudrate & 0x8000 )    {        UART0_STATUS = (1<<U2X);  //Enable 2x speed        baudrate &= ~0x8000;    }    UBRRHI = (unsigned char)(baudrate>>8);    UBRR   = (unsigned char) baudrate;    /* Enable UART receiver and transmitter and receive complete interrupt */    UART0_CONTROL = _BV(RXCIE)|(1<<RXEN)|(1<<TXEN);#endif}/* uart_init *//*************************************************************************Function: uart_getc()Purpose:  return byte from ringbufferReturns:  lower byte:  received byte from ringbuffer          higher byte: last receive error**************************************************************************/unsigned int uart_getc(void){    unsigned char tmptail;    unsigned char data;    if ( UART_RxHead == UART_RxTail ) {        return UART_NO_DATA;   /* no data available */    }    /* calculate /store buffer index */    tmptail = (UART_RxTail + 1) & UART_RX_BUFFER_MASK;    UART_RxTail = tmptail;    /* get data from receive buffer */    data = UART_RxBuf[tmptail];    return (UART_LastRxError << 8) + data;}/* uart_getc *//*************************************************************************Function: uart_ngetc()Purpose:  non-block return byte from ringbufferReturns:  char input**************************************************************************/unsigned char uart_ngetc(void){    while ( !(UART0_STATUS & (1<<RXC)) );    return UART0_DATA;}/* uart_ngetc *//*************************************************************************Function: uart_putc()Purpose:  write byte to ringbuffer for transmitting via UARTInput:    byte to be transmittedReturns:  none**************************************************************************/void uart_putc(unsigned char data){    unsigned char tmphead;    tmphead  = (UART_TxHead + 1) & UART_TX_BUFFER_MASK;    while ( tmphead == UART_TxTail ){        ;/* wait for free space in buffer */    }    UART_TxBuf[tmphead] = data;    UART_TxHead = tmphead;    /* enable UDRE interrupt */    UART0_CONTROL    |= _BV(UART0_UDRIE);}/* uart_putc *//*************************************************************************Function: uart_nputc()Purpose:  non-block write byte to ringbuffer for transmitting via UARTInput:    byte to be transmittedReturns:  none**************************************************************************/void uart_nputc(unsigned char data){  while (!(UART0_STATUS & (1<<UDRE)) ) ;  UART0_DATA = data;}/* uart_nputc *//*************************************************************************Function: uart_puts()Purpose:  transmit string to UARTInput:    string to be transmittedReturns:  none**************************************************************************/void uart_puts(const char *s ){    while (*s)      uart_putc(*s++);}/* uart_puts *//*************************************************************************Function: uart_nputs()Purpose:  non-block transmit string to UARTInput:    string to be transmittedReturns:  none**************************************************************************/void uart_nputs(const char *s ){    while (*s)      uart_nputc(*s++);}/* uart_nputs *//*************************************************************************Function: uart_puts_p()Purpose:  transmit string from program memory to UARTInput:    program memory string to be transmittedReturns:  none**************************************************************************/void uart_puts_p(const char *progmem_s ){    register char c;    while ( (c = pgm_read_byte(progmem_s++)) )      uart_putc(c);}/* uart_puts_p *//*************************************************************************Function: uart_available()Purpose:  Determine the number of bytes waiting in the receive bufferInput:    NoneReturns:  Integer number of bytes in the receive buffer**************************************************************************/int uart_available(void){        return (UART_RX_BUFFER_MASK + UART_RxHead - UART_RxTail) % UART_RX_BUFFER_MASK;}/* uart_available *//*************************************************************************Function: uart_flush()Purpose:  Flush bytes waiting the receive buffer.  Acutally ignores them.Input:    NoneReturns:  None**************************************************************************/void uart_flush(void){        UART_RxHead = UART_RxTail;}/* uart_flush *//* * these functions are only for ATmegas with two USART */#if defined( ATMEGA_USART1 )SIGNAL(UART1_RECEIVE_INTERRUPT)/*************************************************************************Function: UART1 Receive Complete interruptPurpose:  called when the UART1 has received a character**************************************************************************/{    unsigned char tmphead;    unsigned char data;    unsigned char usr;    unsigned char lastRxError;    /* read UART status register and UART data register */    usr  = UART1_STATUS;    data = UART1_DATA;    /* */    lastRxError = (usr & (_BV(FE1)|_BV(DOR1)) );    /* calculate buffer index */    tmphead = ( UART1_RxHead + 1) & UART_RX_BUFFER_MASK;    if ( tmphead == UART1_RxTail ) {        /* error: receive buffer overflow */        lastRxError = UART_BUFFER_OVERFLOW >> 8;    }else{        /* store new index */        UART1_RxHead = tmphead;        /* store received data in buffer */        UART1_RxBuf[tmphead] = data;    }    UART1_LastRxError = lastRxError;}SIGNAL(UART1_TRANSMIT_INTERRUPT)/*************************************************************************Function: UART1 Data Register Empty interruptPurpose:  called when the UART1 is ready to transmit the next byte**************************************************************************/{    unsigned char tmptail;    if ( UART1_TxHead != UART1_TxTail) {        /* calculate and store new buffer index */        tmptail = (UART1_TxTail + 1) & UART_TX_BUFFER_MASK;        UART1_TxTail = tmptail;        /* get one byte from buffer and write it to UART */        UART1_DATA = UART1_TxBuf[tmptail];  /* start transmission */    }else{        /* tx buffer empty, disable UDRE interrupt */        UART1_CONTROL &= ~_BV(UART1_UDRIE);    }}/*************************************************************************Function: uart1_init()Purpose:  initialize UART1 and set baudrateInput:    baudrate using macro UART_BAUD_SELECT()Returns:  none**************************************************************************/void uart1_init(unsigned int baudrate){    UART1_TxHead = 0;    UART1_TxTail = 0;    UART1_RxHead = 0;    UART1_RxTail = 0;    /* Set baud rate */    if ( baudrate & 0x8000 )    {        UART1_STATUS = (1<<U2X1);  //Enable 2x speed      baudrate &= ~0x8000;    }    UBRR1H = (unsigned char)(baudrate>>8);    UBRR1L = (unsigned char) baudrate;    /* Enable USART receiver and transmitter and receive complete interrupt */    UART1_CONTROL = _BV(RXCIE1)|(1<<RXEN1)|(1<<TXEN1);    /* Set frame format: asynchronous, 8data, no parity, 1stop bit */    #ifdef URSEL1    UCSR1C = (1<<URSEL1)|(3<<UCSZ10);    #else    UCSR1C = (3<<UCSZ10);    #endif}/* uart_init *//*************************************************************************Function: uart1_getc()Purpose:  return byte from ringbufferReturns:  lower byte:  received byte from ringbuffer          higher byte: last receive error**************************************************************************/unsigned int uart1_getc(void){    unsigned char tmptail;    unsigned char data;    if ( UART1_RxHead == UART1_RxTail ) {        return UART_NO_DATA;   /* no data available */    }    /* calculate /store buffer index */    tmptail = (UART1_RxTail + 1) & UART_RX_BUFFER_MASK;    UART1_RxTail = tmptail;    /* get data from receive buffer */    data = UART1_RxBuf[tmptail];    return (UART1_LastRxError << 8) + data;}/* uart1_getc *//*************************************************************************Function: uart1_putc()Purpose:  write byte to ringbuffer for transmitting via UARTInput:    byte to be transmittedReturns:  none**************************************************************************/void uart1_putc(unsigned char data){    unsigned char tmphead;    tmphead  = (UART1_TxHead + 1) & UART_TX_BUFFER_MASK;    while ( tmphead == UART1_TxTail ){        ;/* wait for free space in buffer */    }    UART1_TxBuf[tmphead] = data;    UART1_TxHead = tmphead;    /* enable UDRE interrupt */    UART1_CONTROL    |= _BV(UART1_UDRIE);}/* uart1_putc *//*************************************************************************Function: uart1_puts()Purpose:  transmit string to UART1Input:    string to be transmittedReturns:  none**************************************************************************/void uart1_puts(const char *s ){    while (*s)      uart1_putc(*s++);}/* uart1_puts *//*************************************************************************Function: uart1_puts_p()Purpose:  transmit string from program memory to UART1Input:    program memory string to be transmittedReturns:  none**************************************************************************/void uart1_puts_p(const char *progmem_s ){    register char c;    while ( (c = pgm_read_byte(progmem_s++)) )      uart1_putc(c);}/* uart1_puts_p *//*************************************************************************Function: uart1_available()Purpose:  Determine the number of bytes waiting in the receive bufferInput:    NoneReturns:  Integer number of bytes in the receive buffer**************************************************************************/int uart1_available(void){        return (UART_RX_BUFFER_MASK + UART1_RxHead - UART1_RxTail) % UART_RX_BUFFER_MASK;}/* uart1_available *//*************************************************************************Function: uart1_flush()Purpose:  Flush bytes waiting the receive buffer.  Acutally ignores them.Input:    NoneReturns:  None**************************************************************************/void uart1_flush(void){        UART1_RxHead = UART1_RxTail;}/* uart1_flush */#endif