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#ifndef UART_H |
#define UART_H |
/************************************************************************ |
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 |
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LICENSE: |
Copyright (C) 2006 Peter Fleury |
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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. |
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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. |
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************************************************************************/ |
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/** |
* @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 |
*/ |
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/**@{*/ |
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#if (__GNUC__ * 100 + __GNUC_MINOR__) < 304 |
#error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !" |
#endif |
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/* |
** constants and macros |
*/ |
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/** @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) |
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/** @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) |
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/** 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 |
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/* 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 |
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/* |
** 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 */ |
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/* |
** function prototypes |
*/ |
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/** |
@brief Initialize UART and set baudrate |
@param baudrate Specify baudrate using macro UART_BAUD_SELECT() |
@return none |
*/ |
extern void uart_init(unsigned int baudrate); |
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/** |
* @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); |
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/** |
* @brief Put byte to ringbuffer for transmitting via UART |
* @param data byte to be transmitted |
* @return none |
*/ |
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/** @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)) |
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/**@}*/ |
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#endif // UART_H |
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