Modifications to make serial transmit interrupt work more reliably. Also, added the availableForWrite function.

This commit is contained in:
Collin Kidder 2014-12-23 22:37:58 -05:00
parent 4eb05c303b
commit bb341c6d92
3 changed files with 30 additions and 15 deletions

View File

@ -23,7 +23,7 @@
// Constructors ////////////////////////////////////////////////////////////////
USARTClass::USARTClass( Usart* pUsart, IRQn_Type dwIrq, uint32_t dwId, RingBuffer* pRx_buffer, volatile RingBuffer* pTx_buffer )
USARTClass::USARTClass( Usart* pUsart, IRQn_Type dwIrq, uint32_t dwId, RingBuffer* pRx_buffer, RingBuffer* pTx_buffer )
{
_rx_buffer = pRx_buffer;
_tx_buffer = pTx_buffer;
@ -33,7 +33,6 @@ USARTClass::USARTClass( Usart* pUsart, IRQn_Type dwIrq, uint32_t dwId, RingBuffe
_dwId=dwId ;
}
// Public Methods //////////////////////////////////////////////////////////////
void USARTClass::begin( const uint32_t dwBaudRate )
@ -66,6 +65,10 @@ void USARTClass::begin( const uint32_t dwBaudRate, const uint32_t config )
// Enable UART interrupt in NVIC
NVIC_EnableIRQ( _dwIrq ) ;
//make sure both ring buffers are initialized back to empty.
_rx_buffer->_iHead = _rx_buffer->_iTail = 0;
_tx_buffer->_iHead = _tx_buffer->_iTail = 0;
// Enable receiver and transmitter
_pUsart->US_CR = US_CR_RXEN | US_CR_TXEN ;
}
@ -91,6 +94,14 @@ int USARTClass::available( void )
return (uint32_t)(SERIAL_BUFFER_SIZE + _rx_buffer->_iHead - _rx_buffer->_iTail) % SERIAL_BUFFER_SIZE ;
}
int USARTClass::availableForWrite(void)
{
int head = _tx_buffer->_iHead;
int tail = _tx_buffer->_iTail;
if (head >= tail) return SERIAL_BUFFER_SIZE - 1 - head + tail;
return tail - head - 1;
}
int USARTClass::peek( void )
{
if ( _rx_buffer->_iHead == _rx_buffer->_iTail )
@ -142,17 +153,20 @@ void USARTClass::IrqHandler( void )
uint32_t status = _pUsart->US_CSR;
// Did we receive data ?
if ((status & US_CSR_RXRDY) == US_CSR_RXRDY)
_rx_buffer->store_char( _pUsart->US_RHR ) ;
if ((status & US_CSR_RXRDY) == US_CSR_RXRDY)
{
_rx_buffer->store_char(_pUsart->US_RHR);
}
//Do we need to keep sending data?
if ((status & US_CSR_TXRDY) == US_CSR_TXRDY)
{
_pUsart->US_THR = _tx_buffer->_aucBuffer[_tx_buffer->_iTail];
_tx_buffer->_iTail = (unsigned int)(_tx_buffer->_iTail + 1) % SERIAL_BUFFER_SIZE;
if (_tx_buffer->_iTail == _tx_buffer->_iHead) //if this is true we have no more data to transmit
if (_tx_buffer->_iTail != _tx_buffer->_iHead) { //just in case
_pUsart->US_THR = _tx_buffer->_aucBuffer[_tx_buffer->_iTail];
_tx_buffer->_iTail = (unsigned int)(_tx_buffer->_iTail + 1) % SERIAL_BUFFER_SIZE;
}
else
{
_pUsart->US_IDR = US_IDR_TXRDY; //mask off transmit interrupt so we don't get it anymore
_pUsart->US_IDR = US_IDR_TXRDY; //mask off transmit interrupt so we don't get it anymore
}
}

View File

@ -59,8 +59,8 @@
class USARTClass : public HardwareSerial
{
protected:
RingBuffer *_rx_buffer ;
volatile RingBuffer *_tx_buffer;
RingBuffer *_rx_buffer;
RingBuffer *_tx_buffer;
protected:
Usart* _pUsart ;
@ -68,12 +68,13 @@ class USARTClass : public HardwareSerial
uint32_t _dwId ;
public:
USARTClass( Usart* pUsart, IRQn_Type dwIrq, uint32_t dwId, RingBuffer* pRx_buffer, volatile RingBuffer* pTx_buffer ) ;
USARTClass( Usart* pUsart, IRQn_Type dwIrq, uint32_t dwId, RingBuffer* pRx_buffer, RingBuffer* pTx_buffer ) ;
void begin( const uint32_t dwBaudRate ) ;
void begin( const uint32_t dwBaudRate , const uint32_t config ) ;
void end( void ) ;
int available( void ) ;
int availableForWrite(void);
int peek( void ) ;
int read( void ) ;
void flush( void ) ;

View File

@ -317,9 +317,9 @@ void UART_Handler(void)
RingBuffer rx_buffer2;
RingBuffer rx_buffer3;
RingBuffer rx_buffer4;
volatile RingBuffer tx_buffer2;
volatile RingBuffer tx_buffer3;
volatile RingBuffer tx_buffer4;
RingBuffer tx_buffer2;
RingBuffer tx_buffer3;
RingBuffer tx_buffer4;
USARTClass Serial1(USART0, USART0_IRQn, ID_USART0, &rx_buffer2, &tx_buffer2);
void serialEvent1() __attribute__((weak));