LIN_master_SoftwareSerial.cpp

Go to the documentation of this file.

 
// assert platform which supports SoftwareSerial. Note: ARDUINO_ARCH_ESP32 requires library ESPSoftwareSerial
#if defined(ARDUINO_ARCH_AVR) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32) || \
  defined(ARDUINO_ARCH_MEGAAVR) || defined(ARDUINO_ARCH_STM32) || defined(ARDUINO_ARCH_RENESAS)
 
// include files
#include <LIN_master_SoftwareSerial.h>
 
 
LIN_Master_Base::state_t LIN_master_SoftwareSerial::_sendBreak(void)
{
  // if state is wrong, exit immediately
  if (this->state != LIN_Master_Base::STATE_IDLE)
  {
    // print debug message
    DEBUG_PRINT(1, "wrong state 0x%02X", this->state);
 
    // set error state and return immediately
    this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) LIN_Master_Base::ERROR_STATE);
    this->state = LIN_Master_Base::STATE_DONE;
    this->_disableTransmitter();
    return this->state;
  }
 
  // empty buffers, just in case...
  this->SWSerial.flush();
  while (this->SWSerial.available())
    this->SWSerial.read();
 
  // Renesas core does not support listen()/stopListening(), see https://github.com/arduino/ArduinoCore-renesas/issues/522
  #if !defined(ARDUINO_ARCH_RENESAS)
    this->SWSerial.stopListening();
  #endif
 
  // optionally enable transmitter
  this->_enableTransmitter();
 
  // start BREAK directly via GPIO (less overhead than begin()). End BREAK in _sendFrame()
  // Also bug in Renesas core: https://github.com/arduino/ArduinoCore-renesas/issues/523
  digitalWrite(this->pinTx, this->inverseLogic ? HIGH : LOW);
  
  // store BREAK start time
  this->startBreak = micros();
 
  // progress state
  this->state = LIN_Master_Base::STATE_BREAK;
 
  // print debug message
  DEBUG_PRINT(3, " ");
 
  // return state
  return this->state;
 
} // LIN_master_SoftwareSerial::_sendBreak()
 
 
 
LIN_Master_Base::state_t LIN_master_SoftwareSerial::_sendFrame(void)
{
  // if state is wrong, exit immediately
  if (this->state != LIN_Master_Base::STATE_BREAK)
  {
    // print debug message
    DEBUG_PRINT(1, "wrong state 0x%02X", this->state);
 
    // set error state and return immediately
    this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) LIN_Master_Base::ERROR_STATE);
    this->state = LIN_Master_Base::STATE_DONE;
    this->_disableTransmitter();
    return this->state;
  }
 
  // after BREAK duration elapsed, release GPIO again and check for LIN echo
  if ((micros() - this->startBreak) > this->durationBreak)
  {
    // terminate BREAK
    digitalWrite(this->pinTx, this->inverseLogic ? LOW : HIGH);
 
    // assert >=1b BREAK delimiter
    delayMicroseconds(50);
        
    // For STM32, listen must be before write
    #if defined(ARDUINO_ARCH_STM32)
      this->SWSerial.listen(); 
    #endif
 
    // blocking send rest of frame (response: SYNC+ID; request: SYNC+ID+DATA[]+CHK)
    this->SWSerial.write(this->bufTx+1, this->lenTx-1);
    //this->SWSerial.flush();   // not required because write() is blocking. Causes issue on STM32
 
    // optionally disable RS485 transmitter after frame is completed
    this->_disableTransmitter();
 
    // Renesas core does not support listen()/stopListening(), see https://github.com/arduino/ArduinoCore-renesas/issues/522
    // For STM32, listen must be before write above
    #if !defined(ARDUINO_ARCH_RENESAS) && !defined(ARDUINO_ARCH_STM32)
      this->SWSerial.listen(); 
    #endif
    
    // progress state
    this->state = LIN_Master_Base::STATE_BODY;
  
  } // after BREAK elapsed
 
  // print debug message
  DEBUG_PRINT(2, " ");
    
  // return state
  return this->state;
 
} // LIN_master_SoftwareSerial::_sendFrame()
 
 
 
LIN_Master_Base::state_t LIN_master_SoftwareSerial::_receiveFrame(void)
{
  // if state is wrong, exit immediately
  if (this->state != LIN_Master_Base::STATE_BODY)
  {
    // print debug message
    DEBUG_PRINT(1, "wrong state 0x%02X", this->state);
 
    // set error state and return immediately
    this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) LIN_Master_Base::ERROR_STATE);
    this->state = LIN_Master_Base::STATE_DONE;
    this->_disableTransmitter();
    return this->state;
  }
 
// Renesas core does not support listen()/stopListening() --> receive echo & response
#if defined(ARDUINO_ARCH_RENESAS)
 
  // echo + frame body received
  if (this->SWSerial.available() >= this->lenRx)
  {  
    // read into buffer
    this->SWSerial.readBytes(this->bufRx, this->lenRx);
 
// STM32 core receives echo w/o BREAK & response
#elif defined(ARDUINO_ARCH_STM32)
 
  // echo (w/o BREAK) + frame body received
  if (this->SWSerial.available() >= this->lenRx-1)
  {  
    // read into buffer
    this->SWSerial.readBytes(this->bufRx+1, this->lenRx-1);
 
    // emulate only ignored BREAK
    this->bufRx[0] = this->bufTx[0];
 
// other cores only receive slave response
#else
 
  // only response received
  if (this->SWSerial.available() >= this->lenRx - this->lenTx) {
      
    // read into buffer
    this->SWSerial.readBytes(this->bufRx + this->lenTx, this->lenRx - this->lenTx);
 
    // emulate ignored echo for sent bytes (incl. BREAK)
    memcpy(this->bufRx, this->bufTx, this->lenTx);
 
#endif // ARDUINO_ARCH_RENESAS
 
    // check frame for errors
    this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) this->_checkFrame());
 
    // progress state
    this->state = LIN_Master_Base::STATE_DONE;
 
  } // frame body received
  
  // frame body received not yet received
  else
  {
    // check for timeout
    if (micros() - this->timeStart > this->timeoutFrame)
    {
      // print debug message
      DEBUG_PRINT(1, "Rx timeout");
 
      // set error state and return immediately
      this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) LIN_Master_Base::ERROR_TIMEOUT);
      this->state = LIN_Master_Base::STATE_DONE;
      this->_disableTransmitter();
      return this->state;
    }
 
  } // not enough bytes received
  
  // print debug message
  DEBUG_PRINT(2, " ");
  
  // return state
  return this->state;
 
} // LIN_master_SoftwareSerial::_receiveFrame()
 
 
 
#if defined(ARDUINO_ARCH_RENESAS)   // for Renesas core inverse logic is parameter for begin()
  LIN_master_SoftwareSerial::LIN_master_SoftwareSerial(uint8_t PinRx, uint8_t PinTx, bool InverseLogic, const char NameLIN[], const int8_t PinTxEN) : 
    LIN_Master_Base::LIN_Master_Base(NameLIN, PinTxEN), SWSerial(PinRx, PinTx)
#else
  LIN_master_SoftwareSerial::LIN_master_SoftwareSerial(uint8_t PinRx, uint8_t PinTx, bool InverseLogic, const char NameLIN[], const int8_t PinTxEN) : 
    LIN_Master_Base::LIN_Master_Base(NameLIN, PinTxEN), SWSerial(PinRx, PinTx, InverseLogic)
#endif
{
  // Debug serial initialized in begin() -> no debug output here
 
  // store pins used for SW serial
  this->pinRx = PinRx;
  this->pinTx = PinTx;
  this->inverseLogic = InverseLogic;
  
  // must not open connection here, else (at least) ESP32 and ESP8266 fail
 
  // cannot print debug message, as constructor is called before setup()
 
} // LIN_master_SoftwareSerial::LIN_master_SoftwareSerial()
 
 
 
void LIN_master_SoftwareSerial::begin(uint16_t Baudrate)
{
  // call base class method
  LIN_Master_Base::begin(Baudrate);
  
  // open serial interface. Timeout not required here
  this->SWSerial.end();
  #if defined(ARDUINO_ARCH_RENESAS)
    this->SWSerial.begin(this->baudrate, SERIAL_8N1, this->inverseLogic);
  #else
    this->SWSerial.begin(this->baudrate);
  #endif
 
  // calculate duration of BREAK
  this->durationBreak = this->timePerByte * 16 / 10;
 
  // print debug message
  DEBUG_PRINT(2, "ok");
 
} // LIN_master_SoftwareSerial::begin()
 
 
 
void LIN_master_SoftwareSerial::end()
{
  // call base class method
  LIN_Master_Base::end();
    
  // close serial interface
  this->SWSerial.end();
 
  // print debug message
  DEBUG_PRINT(2, " ");
 
} // LIN_master_SoftwareSerial::end()
 
 
#endif // ARDUINO_ARCH_AVR || ARDUINO_ARCH_ESP8266 || ARDUINO_ARCH_ESP32 || ARDUINO_ARCH_MEGAAVR || ARDUINO_ARCH_STM32 || ARDUINO_ARCH_RENESAS
 
 
/*-----------------------------------------------------------------------------
    END OF FILE
-----------------------------------------------------------------------------*/