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- /*
- SoftwareSerial.cpp (formerly NewSoftSerial.cpp) -
- Multi-instance software serial library for Arduino/Wiring
- -- Interrupt-driven receive and other improvements by ladyada
- (http://ladyada.net)
- -- Tuning, circular buffer, derivation from class Print/Stream,
- multi-instance support, porting to 8MHz processors,
- various optimizations, PROGMEM delay tables, inverse logic and
- direct port writing by Mikal Hart (http://www.arduiniana.org)
- -- Pin change interrupt macros by Paul Stoffregen (http://www.pjrc.com)
- -- 20MHz processor support by Garrett Mace (http://www.macetech.com)
- -- ATmega1280/2560 support by Brett Hagman (http://www.roguerobotics.com/)
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- This library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-
- The latest version of this library can always be found at
- http://arduiniana.org.
- */
-
- #ifdef TARGET_LPC1768
-
- //
- // Includes
- //
- //#include <WInterrupts.h>
- #include "../../inc/MarlinConfig.h"
- #include <stdint.h>
- #include <stdarg.h>
- #include "arduino.h"
- #include "pinmapping.h"
- #include "fastio.h"
- #include "SoftwareSerial.h"
-
- void GpioEnableInt(uint32_t port, uint32_t pin, uint32_t mode);
- void GpioDisableInt(uint32_t port, uint32_t pin);
- //
- // Statics
- //
- SoftwareSerial *SoftwareSerial::active_object = 0;
- unsigned char SoftwareSerial::_receive_buffer[_SS_MAX_RX_BUFF];
- volatile uint8_t SoftwareSerial::_receive_buffer_tail = 0;
- volatile uint8_t SoftwareSerial::_receive_buffer_head = 0;
-
- typedef struct _DELAY_TABLE
- {
- long baud;
- uint16_t rx_delay_centering;
- uint16_t rx_delay_intrabit;
- uint16_t rx_delay_stopbit;
- uint16_t tx_delay;
- } DELAY_TABLE;
-
- // rough delay estimation
- static const DELAY_TABLE table[] =
- {
- //baud |rxcenter|rxintra |rxstop |tx
- { 250000, 2, 4, 4, 4, }, //Done but not good due to instruction cycle error
- { 115200, 4, 8, 8, 8, }, //Done but not good due to instruction cycle error
- //{ 74880, 69, 139, 62, 162, }, // estimation
- // { 57600, 100, 185, 1, 208, }, // Done but not good due to instruction cycle error
- //{ 38400, 13, 26, 26, 26, }, // Done
- //{ 19200, 26, 52, 52, 52, }, // Done
- { 9600, 52, 104, 104, 104, }, // Done
- //{ 4800, 104, 208, 208, 208, },
- //{ 2400, 208, 417, 417, 417, },
- //{ 1200, 416, 833, 833, 833,},
- };
-
- //
- // Private methods
- //
-
- #if 0
- /* static */
- inline void SoftwareSerial::tunedDelay(uint32_t count) {
-
- asm volatile(
-
- "mov r3, %[loopsPerMicrosecond] \n\t" //load the initial loop counter
- "1: \n\t"
- "sub r3, r3, #1 \n\t"
- "bne 1b \n\t"
-
- ://empty output list
- :[loopsPerMicrosecond] "r" (count)
- :"r3", "cc" //clobber list
- );
-
- }
- #else
- inline void SoftwareSerial::tunedDelay(uint32_t count) {
- delayMicroseconds(count);
- }
- #endif
-
- // This function sets the current object as the "listening"
- // one and returns true if it replaces another
- bool SoftwareSerial::listen()
- {
- if (!_rx_delay_stopbit)
- return false;
-
- if (active_object != this)
- {
- if (active_object)
- active_object->stopListening();
-
- _buffer_overflow = false;
- _receive_buffer_head = _receive_buffer_tail = 0;
- active_object = this;
-
- setRxIntMsk(true);
- return true;
- }
-
- return false;
- }
-
- // Stop listening. Returns true if we were actually listening.
- bool SoftwareSerial::stopListening()
- {
- if (active_object == this)
- {
- setRxIntMsk(false);
- active_object = NULL;
- return true;
- }
- return false;
- }
-
- //
- // The receive routine called by the interrupt handler
- //
- void SoftwareSerial::recv()
- {
- 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);//__disable_irq();//
-
- // Wait approximately 1/2 of a bit width to "center" the sample
- tunedDelay(_rx_delay_centering);
- // Read each of the 8 bits
- for (uint8_t i=8; i > 0; --i)
- {
- tunedDelay(_rx_delay_intrabit);
- d >>= 1;
- if (rx_pin_read())
- d |= 0x80;
- }
-
- 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
- {
- _buffer_overflow = true;
- }
- tunedDelay(_rx_delay_stopbit);
- // Re-enable interrupts when we're sure to be inside the stop bit
- setRxIntMsk(true);//__enable_irq();//
-
- }
- }
-
- uint32_t SoftwareSerial::rx_pin_read()
- {
- return digitalRead(_receivePin);
- }
-
- //
- // Interrupt handling
- //
-
- /* static */
- inline void SoftwareSerial::handle_interrupt()
- {
- if (active_object)
- {
- active_object->recv();
- }
- }
- extern "C" void intWrapper() {
- SoftwareSerial::handle_interrupt();
- }
- //
- // Constructor
- //
- SoftwareSerial::SoftwareSerial(uint8_t receivePin, uint8_t transmitPin, bool inverse_logic /* = false */) :
- _rx_delay_centering(0),
- _rx_delay_intrabit(0),
- _rx_delay_stopbit(0),
- _tx_delay(0),
- _buffer_overflow(false),
- _inverse_logic(inverse_logic)
- {
- setTX(transmitPin);
- setRX(receivePin);
-
- }
-
- //
- // Destructor
- //
- SoftwareSerial::~SoftwareSerial()
- {
- end();
- }
-
- void SoftwareSerial::setTX(uint8_t tx)
- {
- // First write, then set output. If we do this the other way around,
- // the pin would be output low for a short while before switching to
- // output hihg. Now, it is input with pullup for a short while, which
- // is fine. With inverse logic, either order is fine.
-
- digitalWrite(tx, _inverse_logic ? LOW : HIGH);
- pinMode(tx,OUTPUT);
- _transmitPin = tx;
-
- }
-
- void SoftwareSerial::setRX(uint8_t rx)
- {
- pinMode(rx, INPUT_PULLUP); // pullup for normal logic!
- //if (!_inverse_logic)
- // digitalWrite(rx, HIGH);
- _receivePin = rx;
- _receivePort = LPC1768_PIN_PORT(rx);
- _receivePortPin = LPC1768_PIN_PIN(rx);
- /* GPIO_T * rxPort = digitalPinToPort(rx);
- _receivePortRegister = portInputRegister(rxPort);
- _receiveBitMask = digitalPinToBitMask(rx);*/
-
- }
-
- //
- // Public methods
- //
-
- void SoftwareSerial::begin(long speed)
- {
- _rx_delay_centering = _rx_delay_intrabit = _rx_delay_stopbit = _tx_delay = 0;
-
- for(uint8_t i = 0; i < sizeof(table)/sizeof(table[0]); ++i)
- {
- long baud = table[i].baud;
- if(baud == speed)
- {
- _rx_delay_centering = table[i].rx_delay_centering;
- _rx_delay_intrabit = table[i].rx_delay_intrabit;
- _rx_delay_stopbit = table[i].rx_delay_stopbit;
- _tx_delay = table[i].tx_delay;
- break;
- }
- }
-
- attachInterrupt(_receivePin, intWrapper, CHANGE); //this->handle_interrupt, CHANGE);
-
- listen();
- tunedDelay(_tx_delay);
-
- }
-
- void SoftwareSerial::setRxIntMsk(bool enable)
- {
- if (enable)
- GpioEnableInt(_receivePort,_receivePin,CHANGE);
- else
- GpioDisableInt(_receivePort,_receivePin);
- }
-
- void SoftwareSerial::end()
- {
- stopListening();
- }
-
-
- // Read data from buffer
- int SoftwareSerial::read()
- {
- if (!isListening())
- return -1;
-
- // Empty buffer?
- if (_receive_buffer_head == _receive_buffer_tail)
- return -1;
-
- // Read from "head"
- uint8_t d = _receive_buffer[_receive_buffer_head]; // grab next byte
- _receive_buffer_head = (_receive_buffer_head + 1) % _SS_MAX_RX_BUFF;
- return d;
- }
-
- int SoftwareSerial::available()
- {
- if (!isListening())
- return 0;
-
- return (_receive_buffer_tail + _SS_MAX_RX_BUFF - _receive_buffer_head) % _SS_MAX_RX_BUFF;
- }
-
- size_t SoftwareSerial::write(uint8_t b)
- {
- // By declaring these as local variables, the compiler will put them
- // in registers _before_ disabling interrupts and entering the
- // critical timing sections below, which makes it a lot easier to
- // verify the cycle timings
-
- bool inv = _inverse_logic;
- uint16_t delay = _tx_delay;
-
- if(inv)
- b = ~b;
-
- cli(); // turn off interrupts for a clean txmit
-
- // Write the start bit
- if (inv)
- digitalWrite(_transmitPin, 1);
- else
- digitalWrite(_transmitPin, 0);
-
- tunedDelay(delay);
-
- // Write each of the 8 bits
- for (uint8_t i = 8; i > 0; --i)
- {
- if (b & 1) // choose bit
- digitalWrite(_transmitPin, 1); // send 1 //(GPIO_Desc[_transmitPin].P)->DOUT |= GPIO_Desc[_transmitPin].bit;
- else
- digitalWrite(_transmitPin, 0); // send 0 //(GPIO_Desc[_transmitPin].P)->DOUT &= ~GPIO_Desc[_transmitPin].bit;
-
- tunedDelay(delay);
- b >>= 1;
- }
-
- // restore pin to natural state
- if (inv)
- digitalWrite(_transmitPin, 0);
- else
- digitalWrite(_transmitPin, 1);
-
- sei(); // turn interrupts back on
- tunedDelay(delay);
-
- return 1;
- }
-
- void SoftwareSerial::flush()
- {
- if (!isListening())
- return;
-
- cli();
- _receive_buffer_head = _receive_buffer_tail = 0;
- sei();
- }
-
- int SoftwareSerial::peek()
- {
- if (!isListening())
- return -1;
-
- // Empty buffer?
- if (_receive_buffer_head == _receive_buffer_tail)
- return -1;
-
- // Read from "head"
- return _receive_buffer[_receive_buffer_head];
- }
-
- #endif // TARGET_LPC1768
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