LIN_master_HardwareSerial_STM32.cpp

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// assert STM32 platform
#if defined(ARDUINO_ARCH_STM32)
 
// include files
#include <LIN_master_HardwareSerial_STM32.h>
 
 
LIN_Master_Base::state_t LIN_Master_HardwareSerial_STM32::_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->pSerial->flush();
  while (this->pSerial->available())
    this->pSerial->read();
 
  // if LIN mode is available clear BREAK detection flag for debugging purposes
  #if defined(USART_CR2_LINEN)
    this->huart->Instance->ICR = USART_ICR_LBDCF;
  #endif
 
  // optionally enable transmitter
  this->_enableTransmitter();
 
  // if LIN mode is available generate LIN BREAK (>=13 bit low)
  #if defined(USART_CR2_LINEN)
    this->huart->Instance->RQR |= USART_RQR_SBKRQ;
 
  // w/o LIN mode send 0x00 at 1/2 baudrate
  // Note: don't use Serial.begin() or TE=1 due to HW latency, see https://github.com/stm32duino/Arduino_Core_STM32/issues/2907#issuecomment-3816058235
  #else
    //this->huart->Instance->CR1 &= ~USART_CR1_UE;
    this->huart->Instance->BRR = this->brr * 2;
    //this->huart->Instance->CR1 |= USART_CR1_UE;
    this->pSerial->write((int) 0x00);
  #endif
 
  // progress state
  this->state = LIN_Master_Base::STATE_BREAK;
 
  // print debug message
  DEBUG_PRINT(3, " ");
  
  // return state
  return this->state;
 
} // LIN_Master_HardwareSerial_STM32::_sendBreak()
 
 
 
LIN_Master_Base::state_t LIN_Master_HardwareSerial_STM32::_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;
  }
 
  // byte(s) received (likely BREAK echo)
  if (this->pSerial->available())
  {
    // store echo in Rx
    this->bufRx[0] = this->pSerial->read();
 
    // if LIN mode is available do nothing. BREAK generated using dedicated LIN mode above
    #if defined(USART_CR2_LINEN)
 
    // w/o LIN mode revert baudrate
    // Note: don't use Serial.begin() or TE=1 due to HW latency, see https://github.com/stm32duino/Arduino_Core_STM32/issues/2907#issuecomment-3816058235
    #else
      this->huart->Instance->BRR = this->brr;
    #endif
 
    // send rest of frame (request frame: SYNC+ID+DATA[]+CHK; response frame: SYNC+ID)
    this->pSerial->write(this->bufTx+1, this->lenTx-1);
 
    // progress state
    this->state = LIN_Master_Base::STATE_BODY;
 
  } // BREAK echo received
  
  // no byte(s) 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;
    }
 
  } // no byte(s) received
  
  // print debug message
  DEBUG_PRINT(2, " ");
  
  // return state
  return this->state;
 
} // LIN_Master_HardwareSerial_STM32::_sendFrame()
 
 
 
LIN_Master_Base::state_t LIN_Master_HardwareSerial_STM32::_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;
  }
 
  // optionally disable RS485 transmitter for slave response frames. Len==2 because BREAK is handled already handled in _sendFrame()
  if ((this->type == LIN_Master_Base::SLAVE_RESPONSE) && (this->pSerial->available() == 2))
    this->_disableTransmitter();
 
  // frame body received (-1 because BREAK is handled already handled in _sendFrame())
  if (this->pSerial->available() >= this->lenRx-1)
  {
    // store bytes in Rx
    this->pSerial->readBytes(this->bufRx+1, this->lenRx-1);
 
    // check frame for errors
    this->error = (LIN_Master_Base::error_t) ((int) this->error | (int) this->_checkFrame());
 
    // optionally disable RS485 transmitter after frame is completed
    this->_disableTransmitter();
 
    // 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_HardwareSerial_STM32::_receiveFrame()
 
 
 
LIN_Master_HardwareSerial_STM32::LIN_Master_HardwareSerial_STM32(HardwareSerial &Interface, uint32_t PinRx, 
  uint32_t PinTx, const char NameLIN[], const int8_t PinTxEN) : LIN_Master_Base::LIN_Master_Base(NameLIN, PinTxEN)
{
  // Debug serial initialized in begin() -> no debug output here
 
  // store pointer to used HW serial
  this->pSerial    = &Interface;                              // used serial interface
  this->huart      = Interface.getHandle();                   // pointer to underlying HAL UART handle
  this->pinRx      = PinRx;                                   // receive pin
  this->pinTx      = PinTx;                                   // transmit pin
 
} // LIN_Master_HardwareSerial_STM32::LIN_Master_HardwareSerial_STM32()
 
 
 
void LIN_Master_HardwareSerial_STM32::begin(uint16_t Baudrate)
{
  // call base class method
  LIN_Master_Base::begin(Baudrate);
 
  // just to be sure
  this->pSerial->end();
 
  // remap Rx/Tx pins (before begin()!)
  this->pSerial->setTx(this->pinTx);
  this->pSerial->setRx(this->pinRx);
 
  // open serial interface with optional timeout
  this->pSerial->begin(this->baudrate);
  #if defined(LIN_MASTER_LIN_PORT_TIMEOUT) && (LIN_MASTER_LIN_PORT_TIMEOUT > 0)
    uint32_t startMillis = millis();
    while ((!(*(this->pSerial))) && (millis() - startMillis < LIN_MASTER_LIN_PORT_TIMEOUT));
  #else
    while(!(*(this->pSerial)));
  #endif
 
  // if LIN mode is available enable LIN mode -> BREAK 13b & enable BREAK detection
  #if defined(USART_CR2_LINEN)
    this->huart->Instance->CR1 &= ~USART_CR1_UE;
    this->huart->Instance->CR2 |= USART_CR2_LINEN;
    this->huart->Instance->CR1 |= USART_CR1_UE;
  
  // w/o LIN mode store BRR value for BRK generation
  #else
    this->brr = this->huart->Instance->BRR;
  #endif
 
  // print debug message
  DEBUG_PRINT(2, "ok");
 
} // LIN_Master_HardwareSerial_STM32::begin()
 
 
 
void LIN_Master_HardwareSerial_STM32::end()
{
  // call base class method
  LIN_Master_Base::end();
    
  // close serial interface
  this->pSerial->end();
 
  // disable LIN mode
  this->huart->Instance->CR1 &= ~USART_CR1_UE;
  this->huart->Instance->CR2 &= ~USART_CR2_LINEN;
  this->huart->Instance->CR1 |= USART_CR1_UE;
 
  // print debug message
  DEBUG_PRINT(2, " ");
 
} // LIN_Master_HardwareSerial_STM32::end()
 
#endif // ARDUINO_ARCH_STM32
 
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