LUFA/Drivers/Peripheral/Serial.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *  \brief Master include file for the USART peripheral driver.
  33  *
  34  *  Driver for the USART subsystem on supported USB AVRs.
  35  */
  36
  37 /** \ingroup Group_PeripheralDrivers
  38  *  @defgroup Group_Serial Serial USART Driver - LUFA/Drivers/Peripheral/Serial.h
  39  *
  40  *  \section Sec_Dependencies Module Source Dependencies
  41  *  The following files must be built with any user project that uses this module:
  42  *    - LUFA/Drivers/Peripheral/Serial.c <i>(Makefile source module name: LUFA_SRC_SERIAL)</i>
  43  *
  44  *  \section Module Description
  45  *  Hardware serial USART driver. This module provides an easy to use driver for
  46  *  the setup of and transfer of data over the AVR's USART port.
  47  *
  48  *  @{
  49  */
  50
  51 #ifndef __SERIAL_H__
  52 #define __SERIAL_H__
  53
  54         /* Includes: */
  55                 #include <avr/io.h>
  56                 #include <avr/pgmspace.h>
  57                 #include <stdbool.h>
  58
  59                 #include "../../Common/Common.h"
  60                 #include "../Misc/TerminalCodes.h"
  61
  62         /* Enable C linkage for C++ Compilers: */
  63                 #if defined(__cplusplus)
  64                         extern "C" {
  65                 #endif
  66
  67         /* Public Interface - May be used in end-application: */
  68                 /* Macros: */
  69                         /** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
  70                          *  not set.
  71                          */
  72                         #define SERIAL_UBBRVAL(baud)    ((((F_CPU / 16) + (baud / 2)) / (baud)) - 1)
  73
  74                         /** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
  75                          *  set.
  76                          */
  77                         #define SERIAL_2X_UBBRVAL(baud) ((((F_CPU / 8) + (baud / 2)) / (baud)) - 1)
  78
  79                 /* Function Prototypes: */
  80                         /** Transmits a given string located in program space (FLASH) through the USART.
  81                          *
  82                          *  \param[in] FlashStringPtr  Pointer to a string located in program space.
  83                          */
  84                         void Serial_TxString_P(const char* FlashStringPtr) ATTR_NON_NULL_PTR_ARG(1);
  85
  86                         /** Transmits a given string located in SRAM memory through the USART.
  87                          *
  88                          *  \param[in] StringPtr  Pointer to a string located in SRAM space.
  89                          */
  90                         void Serial_TxString(const char* StringPtr) ATTR_NON_NULL_PTR_ARG(1);
  91
  92                 /* Inline Functions: */
  93                         /** Initializes the USART, ready for serial data transmission and reception. This initializes the interface to
  94                          *  standard 8-bit, no parity, 1 stop bit settings suitable for most applications.
  95                          *
  96                          *  \param[in] BaudRate     Serial baud rate, in bits per second.
  97                          *  \param[in] DoubleSpeed  Enables double speed mode when set, halving the sample time to double the baud rate.
  98                          */
  99                         static inline void Serial_Init(const uint32_t BaudRate,
 100                                                        const bool DoubleSpeed)
 101                         {
 102                                 UBRR1  = (DoubleSpeed ? SERIAL_2X_UBBRVAL(BaudRate) : SERIAL_UBBRVAL(BaudRate));
 103
 104                                 UCSR1C = ((1 << UCSZ11) | (1 << UCSZ10));
 105                                 UCSR1A = (DoubleSpeed ? (1 << U2X1) : 0);
 106                                 UCSR1B = ((1 << TXEN1)  | (1 << RXEN1));
 107
 108                                 DDRD  |= (1 << 3);
 109                                 PORTD |= (1 << 2);
 110                         }
 111
 112                         /** Turns off the USART driver, disabling and returning used hardware to their default configuration. */
 113                         static inline void Serial_ShutDown(void)
 114                         {
 115                                 UCSR1B = 0;
 116                                 UCSR1A = 0;
 117                                 UCSR1C = 0;
 118
 119                                 UBRR1  = 0;
 120
 121                                 DDRD  &= ~(1 << 3);
 122                                 PORTD &= ~(1 << 2);
 123                         }
 124
 125                         /** Indicates whether a character has been received through the USART.
 126                          *
 127                          *  \return Boolean true if a character has been received, false otherwise.
 128                          */
 129                         static inline bool Serial_IsCharReceived(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 130                         static inline bool Serial_IsCharReceived(void)
 131                         {
 132                                 return ((UCSR1A & (1 << RXC1)) ? true : false);
 133                         }
 134
 135                         /** Transmits a given byte through the USART.
 136                          *
 137                          *  \param[in] DataByte  Byte to transmit through the USART.
 138                          */
 139                         static inline void Serial_TxByte(const char DataByte) ATTR_ALWAYS_INLINE;
 140                         static inline void Serial_TxByte(const char DataByte)
 141                         {
 142                                 while (!(UCSR1A & (1 << UDRE1)));
 143                                 UDR1 = DataByte;
 144                         }
 145
 146                         /** Receives a byte from the USART. This function blocks until a byte has been
 147                          *  received; if non-blocking behaviour is required, test for a received character
 148                          *  beforehand with \ref Serial_IsCharReceived().
 149                          *
 150                          *  \return Byte received from the USART.
 151                          */
 152                         static inline char Serial_RxByte(void) ATTR_ALWAYS_INLINE;
 153                         static inline char Serial_RxByte(void)
 154                         {
 155                                 while (!(UCSR1A & (1 << RXC1)));
 156                                 return UDR1;
 157                         }
 158
 159         /* Disable C linkage for C++ Compilers: */
 160                 #if defined(__cplusplus)
 161                         }
 162                 #endif
 163
 164 #endif
 165
 166 /** @} */
 167