serial.h

userial is an Free project building an USB to I2C/SPI/GPIO bridge, using the Atmel AT90USB647 chip.

/*
             LUFA Library
     Copyright (C) Dean Camera, 2009.
              
  dean [at] fourwalledcubicle [dot] com
      www.fourwalledcubicle.com
*/

/*
  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)

  Permission to use, copy, modify, and distribute this software
  and its documentation for any purpose and without fee is hereby
  granted, provided that the above copyright notice appear in all
  copies and that both that the copyright notice and this
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
  software without specific, written prior permission.

  The author disclaim all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \file
 *
 *  Driver for the USART subsystem on supported USB AVRs.
 */
 
#ifndef __SERIAL_H__
#define __SERIAL_H__

	/* Includes: */
		#include <avr/io.h>
		#include <avr/pgmspace.h>
		#include <stdbool.h>
		
		#include "../../Common/Common.h"
		#include "../Misc/TerminalCodes.h"

	/* Enable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			extern "C" {
		#endif

	/* Public Interface - May be used in end-application: */
		/* Macros: */	
			/** Indicates whether a character has been received through the USART - boolean false if no character
			 *  has been received, or non-zero if a character is waiting to be read from the reception buffer.
			 */
			#define Serial_IsCharReceived() ((UCSR1A & (1 << RXC1)) ? true : false)

			/** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
			 *  not set.
			 */
			#define SERIAL_UBBRVAL(baud)    (((F_CPU / 16) / baud) - 1)

			/** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
			 *  set.
			 */
			#define SERIAL_2X_UBBRVAL(baud) (((F_CPU / 8) / baud) - 1)

		/* Function Prototypes: */
			/** Initializes the USART, ready for serial data transmission and reception.
			 *
			 *  \param BaudRate     Baud rate to configure the USART to
			 *  \param DoubleSpeed  Enables double speed mode when set, halving the sample time to double the baud rate
			 */
			void Serial_Init(const uint32_t BaudRate, const bool DoubleSpeed);

			/** Transmits a given string located in program space (FLASH) through the USART.
			 *
			 *  \param FlashStringPtr  Pointer to a string located in program space
			 */
			void Serial_TxString_P(const char *FlashStringPtr) ATTR_NON_NULL_PTR_ARG(1);

			/** Transmits a given string located in SRAM memory through the USART.
			 *
			 *  \param StringPtr  Pointer to a string located in SRAM space
			 */
			void Serial_TxString(const char *StringPtr) ATTR_NON_NULL_PTR_ARG(1);

		/* Inline Functions: */
			/** Transmits a given byte through the USART.
			 *
			 *  \param DataByte  Byte to transmit through the USART
			 */
			static inline void Serial_TxByte(const char DataByte)
			{
				while (!(UCSR1A & (1 << UDRE1)));
				UDR1 = DataByte;
			}

			/** Receives a byte from the USART.
			 *
			 *  \return Byte received from the USART
			 */
			static inline char Serial_RxByte(void)
			{
				while (!(UCSR1A & (1 << RXC1)));
				return UDR1; 
			}

	/* Disable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			}
		#endif
		
#endif