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| 1053 | - | 1 | #ifndef UART_H |
| 2 | #define UART_H |
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| 3 | /************************************************************************ |
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| 4 | Title: Interrupt UART library with receive/transmit circular buffers |
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| 5 | Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury |
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| 6 | File: $Id: uart.h,v 1.8.2.1 2007/07/01 11:14:38 peter Exp $ |
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| 7 | Software: AVR-GCC 4.1, AVR Libc 1.4 |
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| 8 | Hardware: any AVR with built-in UART, tested on AT90S8515 & ATmega8 at 4 Mhz |
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| 9 | License: GNU General Public License |
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| 10 | Usage: see Doxygen manual |
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| 11 | |||
| 12 | LICENSE: |
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| 13 | Copyright (C) 2006 Peter Fleury |
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| 14 | |||
| 15 | This program is free software; you can redistribute it and/or modify |
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| 16 | it under the terms of the GNU General Public License as published by |
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| 17 | the Free Software Foundation; either version 2 of the License, or |
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| 18 | any later version. |
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| 19 | |||
| 20 | This program is distributed in the hope that it will be useful, |
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| 21 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 23 | GNU General Public License for more details. |
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| 24 | |||
| 25 | ************************************************************************/ |
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| 26 | |||
| 27 | /** |
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| 28 | * @defgroup pfleury_uart UART Library |
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| 29 | * @code #include <uart.h> @endcode |
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| 30 | * |
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| 31 | * @brief Interrupt UART library using the built-in UART with transmit and receive circular buffers. |
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| 32 | * |
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| 33 | * This library can be used to transmit and receive data through the built in UART. |
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| 34 | * |
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| 35 | * An interrupt is generated when the UART has finished transmitting or |
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| 36 | * receiving a byte. The interrupt handling routines use circular buffers |
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| 37 | * for buffering received and transmitted data. |
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| 38 | * |
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| 39 | * The UART_RX_BUFFER_SIZE and UART_TX_BUFFER_SIZE constants define |
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| 40 | * the size of the circular buffers in bytes. Note that these constants must be a power of 2. |
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| 41 | * You may need to adapt this constants to your target and your application by adding |
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| 42 | * CDEFS += -DUART_RX_BUFFER_SIZE=nn -DUART_RX_BUFFER_SIZE=nn to your Makefile. |
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| 43 | * |
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| 44 | * @note Based on Atmel Application Note AVR306 |
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| 45 | * @author Peter Fleury pfleury@gmx.ch http://jump.to/fleury |
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| 46 | */ |
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| 47 | |||
| 48 | /**@{*/ |
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| 49 | |||
| 50 | |||
| 51 | #if (__GNUC__ * 100 + __GNUC_MINOR__) < 304 |
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| 52 | #error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !" |
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| 53 | #endif |
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| 54 | |||
| 55 | |||
| 56 | /* |
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| 57 | ** constants and macros |
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| 58 | */ |
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| 59 | |||
| 60 | /** @brief UART Baudrate Expression |
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| 61 | * @param xtalcpu system clock in Mhz, e.g. 4000000L for 4Mhz |
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| 62 | * @param baudrate baudrate in bps, e.g. 1200, 2400, 9600 |
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| 63 | */ |
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| 64 | #define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/((baudRate)*16l)-1) |
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| 65 | |||
| 66 | /** @brief UART Baudrate Expression for ATmega double speed mode |
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| 67 | * @param xtalcpu system clock in Mhz, e.g. 4000000L for 4Mhz |
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| 68 | * @param baudrate baudrate in bps, e.g. 1200, 2400, 9600 |
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| 69 | */ |
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| 70 | #define UART_BAUD_SELECT_DOUBLE_SPEED(baudRate,xtalCpu) (((xtalCpu)/((baudRate)*8l)-1)|0x8000) |
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| 71 | |||
| 72 | |||
| 73 | /** Size of the circular receive buffer, must be power of 2 */ |
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| 74 | #ifndef UART_RX_BUFFER_SIZE |
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| 75 | #define UART_RX_BUFFER_SIZE 32 |
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| 76 | #endif |
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| 77 | /** Size of the circular transmit buffer, must be power of 2 */ |
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| 78 | #ifndef UART_TX_BUFFER_SIZE |
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| 79 | #define UART_TX_BUFFER_SIZE 32 |
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| 80 | #endif |
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| 81 | |||
| 82 | /* test if the size of the circular buffers fits into SRAM */ |
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| 83 | #if ( (UART_RX_BUFFER_SIZE+UART_TX_BUFFER_SIZE) >= (RAMEND-0x60 ) ) |
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| 84 | #error "size of UART_RX_BUFFER_SIZE + UART_TX_BUFFER_SIZE larger than size of SRAM" |
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| 85 | #endif |
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| 86 | |||
| 87 | /* |
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| 88 | ** high byte error return code of uart_getc() |
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| 89 | */ |
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| 90 | #define UART_FRAME_ERROR 0x0800 /* Framing Error by UART */ |
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| 91 | #define UART_OVERRUN_ERROR 0x0400 /* Overrun condition by UART */ |
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| 92 | #define UART_BUFFER_OVERFLOW 0x0200 /* receive ringbuffer overflow */ |
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| 93 | #define UART_NO_DATA 0x0100 /* no receive data available */ |
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| 94 | |||
| 95 | |||
| 96 | /* |
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| 97 | ** function prototypes |
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| 98 | */ |
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| 99 | |||
| 100 | /** |
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| 101 | @brief Initialize UART and set baudrate |
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| 102 | @param baudrate Specify baudrate using macro UART_BAUD_SELECT() |
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| 103 | @return none |
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| 104 | */ |
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| 105 | extern void uart_init(unsigned int baudrate); |
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| 106 | |||
| 107 | |||
| 108 | /** |
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| 109 | * @brief Get received byte from ringbuffer |
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| 110 | * |
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| 111 | * Returns in the lower byte the received character and in the |
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| 112 | * higher byte the last receive error. |
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| 113 | * UART_NO_DATA is returned when no data is available. |
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| 114 | * |
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| 115 | * @param void |
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| 116 | * @return lower byte: received byte from ringbuffer |
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| 117 | * @return higher byte: last receive status |
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| 118 | * - \b 0 successfully received data from UART |
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| 119 | * - \b UART_NO_DATA |
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| 120 | * <br>no receive data available |
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| 121 | * - \b UART_BUFFER_OVERFLOW |
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| 122 | * <br>Receive ringbuffer overflow. |
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| 123 | * We are not reading the receive buffer fast enough, |
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| 124 | * one or more received character have been dropped |
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| 125 | * - \b UART_OVERRUN_ERROR |
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| 126 | * <br>Overrun condition by UART. |
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| 127 | * A character already present in the UART UDR register was |
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| 128 | * not read by the interrupt handler before the next character arrived, |
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| 129 | * one or more received characters have been dropped. |
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| 130 | * - \b UART_FRAME_ERROR |
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| 131 | * <br>Framing Error by UART |
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| 132 | */ |
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| 133 | extern unsigned int uart_getc(void); |
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| 134 | |||
| 135 | |||
| 136 | /** |
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| 137 | * @brief Put byte to ringbuffer for transmitting via UART |
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| 138 | * @param data byte to be transmitted |
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| 139 | * @return none |
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| 140 | */ |
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| 141 | |||
| 142 | |||
| 143 | |||
| 144 | |||
| 145 | /** @brief Initialize USART1 (only available on selected ATmegas) @see uart_init */ |
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| 146 | extern void uart1_init(unsigned int baudrate); |
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| 147 | /** @brief Get received byte of USART1 from ringbuffer. (only available on selected ATmega) @see uart_getc */ |
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| 148 | extern unsigned int uart1_getc(void); |
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| 149 | /** @brief Put byte to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_putc */ |
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| 150 | extern void uart1_putc(unsigned char data); |
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| 151 | /** @brief Put string to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts */ |
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| 152 | extern void uart1_puts(const char *s ); |
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| 153 | /** @brief Put string from program memory to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts_p */ |
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| 154 | extern void uart1_puts_p(const char *s ); |
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| 155 | /** @brief Macro to automatically put a string constant into program memory */ |
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| 156 | #define uart1_puts_P(__s) uart1_puts_p(PSTR(__s)) |
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| 157 | |||
| 158 | /**@}*/ |
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| 159 | |||
| 160 | |||
| 161 | #endif // UART_H |
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| 162 |