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Serial.flush() waits for last character to be transmitted (michele.mazzucchi)

http://code.google.com/p/arduino/issues/detail?id=871
This commit is contained in:
David A. Mellis 2012-08-28 08:02:54 -04:00
parent b7fc69aa9f
commit f9f1d3af3c
2 changed files with 9 additions and 2 deletions

View File

@ -327,6 +327,8 @@ try_again:
*_ubrrh = baud_setting >> 8;
*_ubrrl = baud_setting;
transmitting = false;
sbi(*_ucsrb, _rxen);
sbi(*_ucsrb, _txen);
sbi(*_ucsrb, _rxcie);
@ -376,8 +378,9 @@ int HardwareSerial::read(void)
void HardwareSerial::flush()
{
while (_tx_buffer->head != _tx_buffer->tail)
;
// UDR is kept full while the buffer is not empty, so TXC triggers when EMPTY && SENT
while (transmitting && ! (*_ucsra & _BV(TXC0)));
transmitting = false;
}
size_t HardwareSerial::write(uint8_t c)
@ -394,6 +397,9 @@ size_t HardwareSerial::write(uint8_t c)
_tx_buffer->head = i;
sbi(*_ucsrb, _udrie);
// clear the TXC bit -- "can be cleared by writing a one to its bit location"
transmitting = true;
sbi(*_ucsra, TXC0);
return 1;
}

View File

@ -43,6 +43,7 @@ class HardwareSerial : public Stream
uint8_t _rxcie;
uint8_t _udrie;
uint8_t _u2x;
bool transmitting;
public:
HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,