//
// The receive routine called by the interrupt handler
//
void SoftwareSerial::recv()
{
DebugPulse(_DEBUG_PIN2, 1);
uint8_t d = 0;
// If RX line is high, then we don't see any start bit
// so interrupt is probably not for us
if (_inverse_logic ? rx_pin_read() : !rx_pin_read())
{
// Disable further interrupts during reception, this prevents
// triggering another interrupt directly after we return, which can
// cause problems at higher baudrates.
setRxIntMsk(false);
// Wait approximately 1/2 of a bit width to "center" the sample
tunedDelay(_rx_delay_centering);
DebugPulse(_DEBUG_PIN2, 1);
// Read each of the 8 bits
for (uint8_t i = 8; i > 0; --i)
{
tunedDelay(_rx_delay_intrabit);
d >>= 1;
DebugPulse(_DEBUG_PIN2, 1);
if (rx_pin_read())
d |= 0x80;
}
DebugPulse(_DEBUG_PIN2, 1);
if (_inverse_logic)
d = ~d;
// if buffer full, set the overflow flag and return
uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
if (next != _receive_buffer_head)
{
// save new data in buffer: tail points to where byte goes
_receive_buffer[_receive_buffer_tail] = d; // save new byte
_receive_buffer_tail = next;
}
else
{
DebugPulse(_DEBUG_PIN1, 1);
_buffer_overflow = true;
}
// skip the stop bit
tunedDelay(_rx_delay_stopbit);
DebugPulse(_DEBUG_PIN1, 1);
// Re-enable interrupts when we're sure to be inside the stop bit
setRxIntMsk(true);
}
//
// The receive routine called by the interrupt handler
//
void SoftwareSerial::recv()
{
noInterrupts();
uint8_t d = 0;
// If RX line is high, then we don't see any start bit
// so interrupt is probably not for us
if (invertedLogic ? digitalRead(_rxPin) : !digitalRead(_rxPin))
{
// The very first start bit the sketch receives takes about 5us longer
if(firstStartBit && !isSOCGpio)
{
delayTicks(initRxCenteringDelay);
}
else
{
delayTicks(rxCenteringDelay);
}
for (uint8_t i=8; i > 0; --i)
{
// compensate for the centering delay if the ISR was too late and missed the center of the start bit.
if(i == 8)
{
if(firstStartBit && !isSOCGpio)
{
delayTicks(initRxIntraBitDelay);
}
else
{
delayTicks(firstIntraBitDelay);
}
}
else
{
delayTicks(rxIntraBitDelay);
}
d >>= 1;
if (digitalRead(_rxPin))
d |= 0x80;
firstStartBit = false;
}
if (invertedLogic)
d = ~d;
uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
if (next != _receive_buffer_head)
{
// save new data in buffer: tail points to where byte goes
_receive_buffer[_receive_buffer_tail] = d; // save new byte
_receive_buffer_tail = next;
}
else
{
DebugPulse(_DEBUG_PIN1, 1);
bufferOverflow = true;
}
// wait until we see a stop bit/s or timeout;
uint8_t loopTimeout = 32;
if(invertedLogic)
{
while(digitalRead(_rxPin) && (loopTimeout >0))
{
delayTicks(bitDelay >> 4);
loopTimeout--;
}
}
else
{
while(!digitalRead(_rxPin) && (loopTimeout >0))
{
delayTicks(bitDelay >> 4);
loopTimeout--;
}
}
DebugPulse(_DEBUG_PIN1, 1);
}
