LUFA/Drivers/Peripheral/Serial.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   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  *
  33  *  Driver for the USART subsystem on supported USB AVRs.
  34  */
  35
  36 /** \ingroup Group_PeripheralDrivers
  37  *  @defgroup Group_Serial Serial USART Driver - LUFA/Drivers/Peripheral/Serial.h
  38  *
  39  *  \section Sec_Dependencies Module Source Dependencies
  40  *  The following files must be built with any user project that uses this module:
  41  *    - LUFA/Drivers/Peripheral/Serial.c
  42  *
  43  *  \section Module Description
  44  *  Hardware serial USART driver. This module provides an easy to use driver for
  45  *  the setup of and transfer of data over the AVR's USART port.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __SERIAL_H__
  51 #define __SERIAL_H__
  52
  53         /* Includes: */
  54                 #include <avr/io.h>
  55                 #include <avr/pgmspace.h>
  56                 #include <stdbool.h>
  57
  58                 #include "../../Common/Common.h"
  59                 #include "../Misc/TerminalCodes.h"
  60
  61         /* Enable C linkage for C++ Compilers: */
  62                 #if defined(__cplusplus)
  63                         extern "C" {
  64                 #endif
  65
  66         /* Public Interface - May be used in end-application: */
  67                 /* Macros: */
  68                         /** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
  69                          *  not set.
  70                          */
  71                         #define SERIAL_UBBRVAL(baud)    (((F_CPU / 16) / (baud)) - 1)
  72
  73                         /** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
  74                          *  set.
  75                          */
  76                         #define SERIAL_2X_UBBRVAL(baud) (((F_CPU / 8) / (baud)) - 1)
  77
  78                 /* Pseudo-Function Macros: */
  79                         #if defined(__DOXYGEN__)
  80                                 /** Indicates whether a character has been received through the USART.
  81                                  *
  82                                  *  \return Boolean true if a character has been received, false otherwise
  83                                  */
  84                                 static inline bool Serial_IsCharReceived(void);
  85                         #else
  86                                 #define Serial_IsCharReceived() ((UCSR1A & (1 << RXC1)) ? true : false)
  87                         #endif
  88
  89                 /* Function Prototypes: */
  90                         /** Transmits a given string located in program space (FLASH) through the USART.
  91                          *
  92                          *  \param[in] FlashStringPtr  Pointer to a string located in program space
  93                          */
  94                         void Serial_TxString_P(const char *FlashStringPtr) ATTR_NON_NULL_PTR_ARG(1);
  95
  96                         /** Transmits a given string located in SRAM memory through the USART.
  97                          *
  98                          *  \param[in] StringPtr  Pointer to a string located in SRAM space
  99                          */
 100                         void Serial_TxString(const char *StringPtr) ATTR_NON_NULL_PTR_ARG(1);
 101
 102                 /* Inline Functions: */
 103                         /** Initializes the USART, ready for serial data transmission and reception. This initializes the interface to
 104                          *  standard 8-bit, no parity, 1 stop bit settings suitable for most applications.
 105                          *
 106                          *  \param[in] BaudRate     Serial baud rate, in bits per second
 107                          *  \param[in] DoubleSpeed  Enables double speed mode when set, halving the sample time to double the baud rate
 108                          */
 109                         static inline void Serial_Init(const uint32_t BaudRate, const bool DoubleSpeed)
 110                         {
 111                                 UCSR1A = (DoubleSpeed ? (1 << U2X1) : 0);
 112                                 UCSR1B = ((1 << TXEN1)  | (1 << RXEN1));
 113                                 UCSR1C = ((1 << UCSZ11) | (1 << UCSZ10));
 114
 115                                 DDRD  |= (1 << 3);
 116                                 PORTD |= (1 << 2);
 117
 118                                 UBRR1  = (DoubleSpeed ? SERIAL_2X_UBBRVAL(BaudRate) : SERIAL_UBBRVAL(BaudRate));
 119                         }
 120
 121                         /** Turns off the USART driver, disabling and returning used hardware to their default configuration. */
 122                         static inline void Serial_ShutDown(void)
 123                         {
 124                                 UCSR1A = 0;
 125                                 UCSR1B = 0;
 126                                 UCSR1C = 0;
 127
 128                                 DDRD  &= ~(1 << 3);
 129                                 PORTD &= ~(1 << 2);
 130
 131                                 UBRR1  = 0;
 132                         }
 133
 134                         /** Transmits a given byte through the USART.
 135                          *
 136                          *  \param[in] DataByte  Byte to transmit through the USART
 137                          */
 138                         static inline void Serial_TxByte(const char DataByte)
 139                         {
 140                                 while (!(UCSR1A & (1 << UDRE1)));
 141                                 UDR1 = DataByte;
 142                         }
 143
 144                         /** Receives a byte from the USART.
 145                          *
 146                          *  \return Byte received from the USART
 147                          */
 148                         static inline char Serial_RxByte(void)
 149                         {
 150                                 while (!(UCSR1A & (1 << RXC1)));
 151                                 return UDR1;
 152                         }
 153
 154         /* Disable C linkage for C++ Compilers: */
 155                 #if defined(__cplusplus)
 156                         }
 157                 #endif
 158
 159 #endif
 160
 161 /** @} */