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