/*! \file uart.h \brief UART driver with buffer support. */
//*****************************************************************************
//
// File Name : 'uart.h'
// Title : UART driver with buffer support
// Author : Pascal Stang - Copyright (C) 2000-2002
// Created : 11/22/2000
// Revised : 02/01/2004
// Version : 1.3
// Target MCU : ATMEL AVR Series
// Editor Tabs : 4
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
/// \ingroup driver_avr
/// \defgroup uart UART Driver/Function Library (uart.c)
/// \code #include "uart.h" \endcode
/// \par Overview
/// This library provides both buffered and unbuffered transmit and receive
/// functions for the AVR processor UART. Buffered access means that the
/// UART can transmit and receive data in the "background", while your code
/// continues executing. Also included are functions to initialize the
/// UART, set the baud rate, flush the buffers, and check buffer status.
///
/// \note For full text output functionality, you may wish to use the rprintf
/// functions along with this driver.
///
/// \par About UART operations
/// Most Atmel AVR-series processors contain one or more hardware UARTs
/// (aka, serial ports). UART serial ports can communicate with other
/// serial ports of the same type, like those used on PCs. In general,
/// UARTs are used to communicate with devices that are RS-232 compatible
/// (RS-232 is a certain kind of serial port).
/// \par
/// By far, the most common use for serial communications on AVR processors
/// is for sending information and data to a PC running a terminal program.
/// Here is an exmaple:
/// \code
/// uartInit(); // initialize UART (serial port)
/// uartSetBaudRate(9600); // set UART speed to 9600 baud
/// rprintfInit(uartSendByte); // configure rprintf to use UART for output
/// rprintf("Hello World\r\n"); // send "hello world" message via serial port
/// \endcode
///
/// \warning The CPU frequency (F_CPU) must be set correctly in \c global.h
/// for the UART library to calculate correct baud rates. Furthermore,
/// certain CPU frequencies will not produce exact baud rates due to
/// integer frequency division round-off. See your AVR processor's
/// datasheet for full details.
//
//*****************************************************************************
//@{
#ifndef UART_H
#define UART_H
#include "global.h"
#include "buffer.h"
//! Default uart baud rate.
/// This is the default speed after a uartInit() command,
/// and can be changed by using uartSetBaudRate().
#define UART_DEFAULT_BAUD_RATE 9600
// buffer memory allocation defines
// buffer sizes
#ifndef UART_TX_BUFFER_SIZE
//! Number of bytes for uart transmit buffer.
/// Do not change this value in uart.h, but rather override
/// it with the desired value defined in your project's global.h
#define UART_TX_BUFFER_SIZE 0x0040
#endif
#ifndef UART_RX_BUFFER_SIZE
//! Number of bytes for uart receive buffer.
/// Do not change this value in uart.h, but rather override
/// it with the desired value defined in your project's global.h
#define UART_RX_BUFFER_SIZE 0x0040
#endif
// define this key if you wish to use
// external RAM for the UART buffers
//#define UART_BUFFER_EXTERNAL_RAM
#ifdef UART_BUFFER_EXTERNAL_RAM
// absolute address of uart buffers
#define UART_TX_BUFFER_ADDR 0x1000
#define UART_RX_BUFFER_ADDR 0x1100
#endif
//! Type of interrupt handler to use for uart interrupts.
/// Value may be SIGNAL or INTERRUPT.
/// \warning Do not change unless you know what you're doing.
#ifndef UART_INTERRUPT_HANDLER
#define UART_INTERRUPT_HANDLER SIGNAL
#endif
// compatibility with most newer processors
#ifdef UCSRB
#define UCR UCSRB
#endif
// compatibility with old Mega processors
#if defined(UBRR) && !defined(UBRRL)
#define UBRRL UBRR
#endif
// compatibility with megaXX8 processors
#if defined(__AVR_ATmega88__) || \
defined(__AVR_ATmega168__) || \
defined(__AVR_ATmega644__)
#define UDR UDR0
#define UCR UCSR0B
#define RXCIE RXCIE0
#define TXCIE TXCIE0
#define RXC RXC0
#define TXC TXC0
#define RXEN RXEN0
#define TXEN TXEN0
#define UBRRL UBRR0L
#define UBRRH UBRR0H
#define SIG_UART_TRANS SIG_USART_TRANS
#define SIG_UART_RECV SIG_USART_RECV
#define SIG_UART_DATA SIG_USART_DATA
#endif
// compatibility with mega169 processors
#if defined(__AVR_ATmega169__)
#define SIG_UART_TRANS SIG_USART_TRANS
#define SIG_UART_RECV SIG_USART_RECV
#define SIG_UART_DATA SIG_USART_DATA
#endif
// compatibility with dual-uart processors
// (if you need to use both uarts, please use the uart2 library)
#if defined(__AVR_ATmega161__)
#define UDR UDR0
#define UCR UCSR0B
#define UBRRL UBRR0
#define SIG_UART_TRANS SIG_UART0_TRANS
#define SIG_UART_RECV SIG_UART0_RECV
#define SIG_UART_DATA SIG_UART0_DATA
#endif
#if defined(__AVR_ATmega128__)
#ifdef UART_USE_UART1
#define UDR UDR1
#define UCR UCSR1B
#define UBRRL UBRR1L
#define UBRRH UBRR1H
#define SIG_UART_TRANS SIG_UART1_TRANS
#define SIG_UART_RECV SIG_UART1_RECV
#define SIG_UART_DATA SIG_UART1_DATA
#else
#define UDR UDR0
#define UCR UCSR0B
#define UBRRL UBRR0L
#define UBRRH UBRR0H
#define SIG_UART_TRANS SIG_UART0_TRANS
#define SIG_UART_RECV SIG_UART0_RECV
#define SIG_UART_DATA SIG_UART0_DATA
#endif
#endif
// functions
//! Initializes uart.
/// \note After running this init function, the processor
/// I/O pins that used for uart communications (RXD, TXD)
/// are no long available for general purpose I/O.
void uartInit(void);
//! Initializes transmit and receive buffers.
/// Automatically called from uartInit()
void uartInitBuffers(void);
//! Redirects received data to a user function.
///
void uartSetRxHandler(void (*rx_func)(unsigned char c));
//! Sets the uart baud rate.
/// Argument should be in bits-per-second, like \c uartSetBaudRate(9600);
void uartSetBaudRate(u32 baudrate);
//! Returns pointer to the receive buffer structure.
///
cBuffer* uartGetRxBuffer(void);
//! Returns pointer to the transmit buffer structure.
///
cBuffer* uartGetTxBuffer(void);
//! Sends a single byte over the uart.
/// \note This function waits for the uart to be ready,
/// therefore, consecutive calls to uartSendByte() will
/// go only as fast as the data can be sent over the
/// serial port.
void uartSendByte(u08 data);
//! Gets a single byte from the uart receive buffer.
/// Returns the byte, or -1 if no byte is available (getchar-style).
int uartGetByte(void);
//! Gets a single byte from the uart receive buffer.
/// Function returns TRUE if data was available, FALSE if not.
/// Actual data is returned in variable pointed to by "data".
/// Example usage:
/// \code
/// char myReceivedByte;
/// uartReceiveByte( &myReceivedByte );
/// \endcode
u08 uartReceiveByte(u08* data);
//! Returns TRUE/FALSE if receive buffer is empty/not-empty.
///
u08 uartReceiveBufferIsEmpty(void);
//! Flushes (deletes) all data from receive buffer.
///
void uartFlushReceiveBuffer(void);
//! Add byte to end of uart Tx buffer.
/// Returns TRUE if successful, FALSE if failed (no room left in buffer).
u08 uartAddToTxBuffer(u08 data);
//! Begins transmission of the transmit buffer under interrupt control.
///
void uartSendTxBuffer(void);
//! Sends a block of data via the uart using interrupt control.
/// \param buffer pointer to data to be sent
/// \param nBytes length of data (number of bytes to sent)
u08 uartSendBuffer(char *buffer, u16 nBytes);
#endif
//@}
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