uart/usart/usart.cpp

#include "usart.h"

//////////////////////////////////////////////////////////////////////////
uint8_t USART0::readUCSRC()
{
	uint8_t ui8UCSRC;
	
#ifdef USART_SHAREDIO
	ui8UCSRC = UBRRH;
	ui8UCSRC = UCSRC;
#else
	ui8UCSRC = *m_vui8pUCSRC;
#endif

	return ui8UCSRC;
}

//////////////////////////////////////////////////////////////////////////
void USART0::setUCSRC( uint8_t ui8UCSRC )
{
#ifdef USART_SHAREDIO
	*m_vui8pUCSRC = ( 1 << URSEL ) | ui8UCSRC;
#else
	*m_vui8pUCSRC = ui8UCSRC;
#endif
}

//////////////////////////////////////////////////////////////////////////
void USART0::setRXState( bool bEnable )
{
	if( bEnable )
	{
		*m_vui8pUCSRB |= ( 1 << RXEN_D );
	}
	else
	{
		*m_vui8pUCSRB &= ~( 1 << RXEN_D );
	}
}

//////////////////////////////////////////////////////////////////////////
void USART0::setTXState( bool bEnable )
{
	if( bEnable )
	{
		*m_vui8pUCSRB |= ( 1 << TXEN_D );
	}
	else
	{
		*m_vui8pUCSRB &= ~( 1 << TXEN_D );
	}
}

//////////////////////////////////////////////////////////////////////////
void USART0::setBaudRate( uint32_t ui32BaudRate )
{
	uint16_t ui16UBRR = ( ( F_CPU / ( 16 * ui32BaudRate ) ) - 1 );
	*m_vui8pUBRRH = static_cast<uint8_t>( ui16UBRR >> 8 );
	*m_vui8pUBRRL = static_cast<uint8_t>( ui16UBRR );
}

//////////////////////////////////////////////////////////////////////////
void USART0::setDataBits( uint8_t ui8DataBits )
{
	uint8_t ui8UCSRC = readUCSRC();
	
	if( ui8DataBits < 5 )
	{
		ui8DataBits = 5;
	}
	else if( ui8DataBits > 9 )
	{
		ui8DataBits = 9;
	}
	
	if( ui8DataBits <= 8 )
	{
		bool bZeroBit = ( ui8DataBits - 5 ) & 1;
		bool bOneBit = ( ( ui8DataBits - 5 ) >> 1 ) & 1;
		
		if( bZeroBit )
		{
			ui8UCSRC |= ( 1 << UCSZ0_D );
		}
		else
		{
			ui8UCSRC &= ~( 1 << UCSZ0_D );
		}
		
		if( bOneBit )
		{
			ui8UCSRC |= ( 1 << UCSZ1_D );
		}
		else
		{
			ui8UCSRC &= ~( 1 << UCSZ1_D );
		}
		
		*m_vui8pUCSRB &= ~( 1 << UCSZ2_D );
	}
	else
	{
		ui8UCSRC |= ( 1 << UCSZ1_D ) | ( 1 << UCSZ0_D );
		*m_vui8pUCSRB |= ( 1 << UCSZ2_D );
	}
	
	setUCSRC( ui8UCSRC );
}

//////////////////////////////////////////////////////////////////////////
void USART0::setParity( Parity enmParity )
{
	uint8_t ui8UCSRC = readUCSRC();
	
	if( enmParity == Parity::DISABLED )
	{
		ui8UCSRC &= ~( ( 1 << UPM1_D ) | ( 1 << UPM0_D ) );
	}
	else if( enmParity == Parity::ODD )
	{
		ui8UCSRC |= ( ( 1 << UPM1_D ) | ( 1 << UPM0_D ) );
	}
	else if( enmParity == Parity::EVEN )
	{
		ui8UCSRC &= ~( ( 1 << UPM0_D ) );
		ui8UCSRC |= ( ( 1 << UPM1_D ) );
	}
	
	setUCSRC( ui8UCSRC );
}

//////////////////////////////////////////////////////////////////////////
void USART0::setStopBits( StopBit enmStopBits )
{
	uint8_t ui8UCSRC = readUCSRC();
	
	if( enmStopBits == StopBit::ONE )
	{
		ui8UCSRC &= ~( 1 << USBS_D );
	}
	else if( enmStopBits == StopBit::TWO )
	{
		ui8UCSRC |= ( 1 << USBS_D );
	}
	
	setUCSRC( ui8UCSRC );
}

//////////////////////////////////////////////////////////////////////////
void USART0::setMode( Mode enmMode )
{
	uint8_t ui8UCSRC = readUCSRC();

#ifdef USART_SPI
	if( enmMode == Mode::ASYNCHRONOUS )
	{
		ui8UCSRC &= ~( ( 1 << UMSEL1_D ) | ( 1 << UMSEL0_D ) );
	}
	else if( enmMode == Mode::SYNCHRONOUS )
	{
		ui8UCSRC &= ~( 1 << UMSEL1_D );
		ui8UCSRC |= ( 1 << UMSEL0_D );
	}
	else if( enmMode == Mode::MASTERSPI )
	{
		ui8UCSRC |= ( ( 1 << UMSEL1_D ) | ( 1 << UMSEL0_D ) );
	}
#else
	if( enmMode == Mode::ASYNCHRONOUS )
	{
		ui8UCSRC &= ~( 1 << UMSEL_D );
	}
	else if( enmMode == Mode::SYNCHRONOUS )
	{
		ui8UCSRC |= ( 1 << UMSEL_D );
	}
#endif

	setUCSRC( ui8UCSRC );
}

//////////////////////////////////////////////////////////////////////////
USART0::USART0()
{
#ifdef USART_SHAREDIO
	m_vui8pUCSRA = &UCSRA;
	m_vui8pUCSRB = &UCSRB;
	m_vui8pUCSRC = &UCSRC;
	m_vui8pUBRRH = &UBRRH;
	m_vui8pUBRRL = &UBRRL;
	m_vui8pUDR = &UDR;
#endif

#ifndef USART_SHAREDIO
	m_vui8pUCSRA = &UCSR0A;
	m_vui8pUCSRB = &UCSR0B;
	m_vui8pUCSRC = &UCSR0C;
	m_vui8pUBRRH = &UBRR0H;
	m_vui8pUBRRL = &UBRR0L;
	m_vui8pUDR = &UDR0;
#endif
}

//////////////////////////////////////////////////////////////////////////
USART0::~USART0()
{}

//////////////////////////////////////////////////////////////////////////
void USART0::init( uint32_t ui32BaudRate /* = 9600 */, uint8_t ui8DataBits /* = 8 */, Parity enmParity /* = Parity::DISABLED */, StopBit enmStopBits /* = StopBit::ONE */, Mode enmMode /* = Mode::ASYNCHRONOUS */ )
{
	setBaudRate( ui32BaudRate );
	setDataBits( ui8DataBits );
	setParity( enmParity );
	setStopBits( enmStopBits );
	setMode( enmMode );

	setRXState( true );
	setTXState( true );
}

//////////////////////////////////////////////////////////////////////////
bool USART0::receiveByte( uint8_t &ui8Data, uint32_t ui32DelayMS )
{
	const uint8_t ui8ClockCyclesPerIteration = 6;
	double dDelayS = ui32DelayMS / 1000.0;
	
	uint32_t ui32Iterations = static_cast<uint32_t>( ( dDelayS * F_CPU ) / ui8ClockCyclesPerIteration );

	do
	{
		if( ( *m_vui8pUCSRA & ( 1 << RXC_D ) ) )
		{
			ui8Data = *m_vui8pUDR;
			return true;
		}
	} while( --ui32Iterations > 0 );
	
	return false;
}

//////////////////////////////////////////////////////////////////////////
uint8_t USART0::receiveByte()
{
	while( !( *m_vui8pUCSRA & ( 1 << RXC_D ) ) );
	
	return *m_vui8pUDR;
}

//////////////////////////////////////////////////////////////////////////
bool USART0::receiveLine( char *szBuffer, size_t sizeLength, const char *szLineTerminator /* = "\r\n" */, size_t sizeMaxSize /* = 1024 */ )
{
	size_t sizeReceived = 0;

	while( sizeReceived < sizeMaxSize - 1 && sizeReceived < sizeLength - 1 )
	{
		szBuffer[sizeReceived++] = receiveByte();
		szBuffer[sizeReceived] = '\0';
		
		if( strstr( szBuffer, szLineTerminator ) )
		{
			return true;
		}
	}

	return false;
}

//////////////////////////////////////////////////////////////////////////
void USART0::transmitByte( uint8_t ui8Data )
{
	while( !( *m_vui8pUCSRA & ( 1 << UDRE_D ) ) );
	
	*m_vui8pUDR = ui8Data;
}

//////////////////////////////////////////////////////////////////////////
void USART0::transmitString( const char *szString )
{
	while( *szString != '\0' )
	{
		transmitByte( *szString++ );
	}
}

#ifdef SECOND_USART

//////////////////////////////////////////////////////////////////////////
USART1::USART1()
{
	m_vui8pUCSRA = &UCSR1A;
	m_vui8pUCSRB = &UCSR1B;
	m_vui8pUCSRC = &UCSR1C;
	m_vui8pUBRRH = &UBRR1H;
	m_vui8pUBRRL = &UBRR1L;
	m_vui8pUDR = &UDR1;
}

//////////////////////////////////////////////////////////////////////////
USART1::~USART1()
{}

#endif