text: /*!
   * \file      sx1276.c
   *
   * \brief     SX1276 driver implementation
   *
   * \copyright Revised BSD License, see section \ref LICENSE.
   *
   * \code
   *                ______                              _
   *               / _____)             _              | |
   *              ( (____  _____ ____ _| |_ _____  ____| |__
   *               \____ \| ___ |    (_   _) ___ |/ ___)  _ \
   *               _____) ) ____| | | || |_| ____( (___| | | |
   *              (______/|_____)_|_|_| \__)_____)\____)_| |_|
   *              (C)2013-2017 Semtech
   *
   * \endcode
   *
   * \author    Miguel Luis ( Semtech )
   *
   * \author    Gregory Cristian ( Semtech )
   *
   * \author    Wael Guibene ( Semtech )
   */
  #include <math.h>
  #include <string.h>
  #include "utilities.h"
  #include "timer.h"
  #include "radio.h"
  #include "delay.h"
  #include "sx1276.h"
  #include "sx1276-board.h"
  
  /*
   * Local types definition
   */
  
  /*!
   * Radio registers definition
   */
  typedef struct
  {
      RadioModems_t Modem;
      uint8_t       Addr;
      uint8_t       Value;
  }RadioRegisters_t;
  
  /*!
   * FSK bandwidth definition
   */
  typedef struct
  {
      uint32_t bandwidth;
      uint8_t  RegValue;
  }FskBandwidth_t;
  
  
  /*
   * Private functions prototypes
   */
  
  /*!
   * Performs the Rx chain calibration for LF and HF bands
   * \remark Must be called just after the reset so all registers are at their
   *         default values
   */
  static void RxChainCalibration( void );
  
  /*!
   * \brief Sets the SX1276 in transmission mode for the given time
   * \param [IN] timeout Transmission timeout [ms] [0: continuous, others timeout]
   */
  void SX1276SetTx( uint32_t timeout );
  
  /*!
   * \brief Writes the buffer contents to the SX1276 FIFO
   *
   * \param [IN] buffer Buffer containing data to be put on the FIFO.
   * \param [IN] size Number of bytes to be written to the FIFO
   */
  void SX1276WriteFifo( uint8_t *buffer, uint8_t size );
  
  /*!
   * \brief Reads the contents of the SX1276 FIFO
   *
   * \param [OUT] buffer Buffer where to copy the FIFO read data.
   * \param [IN] size Number of bytes to be read from the FIFO
   */
  void SX1276ReadFifo( uint8_t *buffer, uint8_t size );
  
  /*!
   * \brief Sets the SX1276 operating mode
   *
   * \param [IN] opMode New operating mode
   */
  void SX1276SetOpMode( uint8_t opMode );
  
  /*
   * SX1276 DIO IRQ callback functions prototype
   */
  
  /*!
   * \brief DIO 0 IRQ callback
   */
  void SX1276OnDio0Irq( void* context );
  
  /*!
   * \brief DIO 1 IRQ callback
   */
  void SX1276OnDio1Irq( void* context );
  
  /*!
   * \brief DIO 2 IRQ callback
   */
  void SX1276OnDio2Irq( void* context );
  
  /*!
   * \brief DIO 3 IRQ callback
   */
  void SX1276OnDio3Irq( void* context );
  
  /*!
   * \brief DIO 4 IRQ callback
   */
  void SX1276OnDio4Irq( void* context );
  
  /*!
   * \brief DIO 5 IRQ callback
   */
  void SX1276OnDio5Irq( void* context );
  
  /*!
   * \brief Tx & Rx timeout timer callback
   */
  void SX1276OnTimeoutIrq( void* context );
  
  /*
   * Private global constants
   */
  
  /*!
   * Radio hardware registers initialization
   *
   * \remark RADIO_INIT_REGISTERS_VALUE is defined in sx1276-board.h file
   */
  const RadioRegisters_t RadioRegsInit[] = RADIO_INIT_REGISTERS_VALUE;
  
  /*!
   * Constant values need to compute the RSSI value
   */
  #define RSSI_OFFSET_LF                              -164
  #define RSSI_OFFSET_HF                              -157
  
  /*!
   * Precomputed FSK bandwidth registers values
   */
  const FskBandwidth_t FskBandwidths[] =
  {
      { 2600  , 0x17 },
      { 3100  , 0x0F },
      { 3900  , 0x07 },
      { 5200  , 0x16 },
      { 6300  , 0x0E },
      { 7800  , 0x06 },
      { 10400 , 0x15 },
      { 12500 , 0x0D },
      { 15600 , 0x05 },
      { 20800 , 0x14 },
      { 25000 , 0x0C },
      { 31300 , 0x04 },
      { 41700 , 0x13 },
      { 50000 , 0x0B },
      { 62500 , 0x03 },
      { 83333 , 0x12 },
      { 100000, 0x0A },
      { 125000, 0x02 },
      { 166700, 0x11 },
      { 200000, 0x09 },
      { 250000, 0x01 },
      { 300000, 0x00 }, // Invalid Bandwidth
  };
  
  /*
   * Private global variables
   */
  
  /*!
   * Radio callbacks variable
   */
  static RadioEvents_t *RadioEvents;
  
  /*!
   * Reception buffer
   */
  static uint8_t RxTxBuffer[RX_BUFFER_SIZE];
  
  /*
   * Public global variables
   */
  
  /*!
   * Radio hardware and global parameters
   */
  SX1276_t SX1276;
  
  /*!
   * Hardware DIO IRQ callback initialization
   */
  DioIrqHandler *DioIrq[] = { SX1276OnDio0Irq, SX1276OnDio1Irq,
                              SX1276OnDio2Irq, SX1276OnDio3Irq,
                              SX1276OnDio4Irq, NULL };
  
  /*!
   * Tx and Rx timers
   */
  TimerEvent_t TxTimeoutTimer;
  TimerEvent_t RxTimeoutTimer;
  TimerEvent_t RxTimeoutSyncWord;
  
  /*
   * Radio driver functions implementation
   */
  
  void SX1276Init( RadioEvents_t *events )
  {
      uint8_t i;
  
      RadioEvents = events;
  
      // Initialize driver timeout timers
      TimerInit( &TxTimeoutTimer, SX1276OnTimeoutIrq );
      TimerInit( &RxTimeoutTimer, SX1276OnTimeoutIrq );
      TimerInit( &RxTimeoutSyncWord, SX1276OnTimeoutIrq );
  
      SX1276Reset( );
  
      RxChainCalibration( );
  
      SX1276SetOpMode( RF_OPMODE_SLEEP );
  
      SX1276IoIrqInit( DioIrq );
  
      for( i = 0; i < sizeof( RadioRegsInit ) / sizeof( RadioRegisters_t ); i++ )
      {
          SX1276SetModem( RadioRegsInit[i].Modem );
          SX1276Write( RadioRegsInit[i].Addr, RadioRegsInit[i].Value );
      }
  
      SX1276SetModem( MODEM_FSK );
  
      SX1276.Settings.State = RF_IDLE;
  }
  
  RadioState_t SX1276GetStatus( void )
  {
      return SX1276.Settings.State;
  }
  
  void SX1276SetChannel( uint32_t freq )
  {
      SX1276.Settings.Channel = freq;
      freq = ( uint32_t )( ( double )freq / ( double )FREQ_STEP );
      SX1276Write( REG_FRFMSB, ( uint8_t )( ( freq >> 16 ) & 0xFF ) );
      SX1276Write( REG_FRFMID, ( uint8_t )( ( freq >> 8 ) & 0xFF ) );
      SX1276Write( REG_FRFLSB, ( uint8_t )( freq & 0xFF ) );
  }
  
  bool SX1276IsChannelFree( RadioModems_t modem, uint32_t freq, int16_t rssiThresh, uint32_t maxCarrierSenseTime )
  {
      bool status = true;
      int16_t rssi = 0;
      uint32_t carrierSenseTime = 0;
  
      SX1276SetSleep( );
  
      SX1276SetModem( modem );
  
      SX1276SetChannel( freq );
  
      SX1276SetOpMode( RF_OPMODE_RECEIVER );
  
      DelayMs( 1 );
  
      carrierSenseTime = TimerGetCurrentTime( );
  
      // Perform carrier sense for maxCarrierSenseTime
      while( TimerGetElapsedTime( carrierSenseTime ) < maxCarrierSenseTime )
      {
          rssi = SX1276ReadRssi( modem );
  
          if( rssi > rssiThresh )
          {
              status = false;
              break;
          }
      }
      SX1276SetSleep( );
      return status;
  }
  
  uint32_t SX1276Random( void )
  {
      uint8_t i;
      uint32_t rnd = 0;
  
      /*
       * Radio setup for random number generation
       */
      // Set LoRa modem ON
      SX1276SetModem( MODEM_LORA );
  
      // Disable LoRa modem interrupts
      SX1276Write( REG_LR_IRQFLAGSMASK, RFLR_IRQFLAGS_RXTIMEOUT |
                    RFLR_IRQFLAGS_RXDONE |
                    RFLR_IRQFLAGS_PAYLOADCRCERROR |
                    RFLR_IRQFLAGS_VALIDHEADER |
                    RFLR_IRQFLAGS_TXDONE |
                    RFLR_IRQFLAGS_CADDONE |
                    RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL |
                    RFLR_IRQFLAGS_CADDETECTED );
  
      // Set radio in continuous reception
      SX1276SetOpMode( RF_OPMODE_RECEIVER );
  
      for( i = 0; i < 32; i++ )
      {
          DelayMs( 1 );
          // Unfiltered RSSI value reading. Only takes the LSB value
          rnd |= ( ( uint32_t )SX1276Read( REG_LR_RSSIWIDEBAND ) & 0x01 ) << i;
      }
  
      SX1276SetSleep( );
  
      return rnd;
  }
  
  /*!
   * Performs the Rx chain calibration for LF and HF bands
   * \remark Must be called just after the reset so all registers are at their
   *         default values
   */
  static void RxChainCalibration( void )
  {
      uint8_t regPaConfigInitVal;
      uint32_t initialFreq;
  
      // Save context
      regPaConfigInitVal = SX1276Read( REG_PACONFIG );
      initialFreq = ( double )( ( ( uint32_t )SX1276Read( REG_FRFMSB ) << 16 ) |
                                ( ( uint32_t )SX1276Read( REG_FRFMID ) << 8 ) |
                                ( ( uint32_t )SX1276Read( REG_FRFLSB ) ) ) * ( double )FREQ_STEP;
  
      // Cut the PA just in case, RFO output, power = -1 dBm
      SX1276Write( REG_PACONFIG, 0x00 );
  
      // Launch Rx chain calibration for LF band
      SX1276Write( REG_IMAGECAL, ( SX1276Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_MASK ) | RF_IMAGECAL_IMAGECAL_START );
      while( ( SX1276Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_RUNNING ) == RF_IMAGECAL_IMAGECAL_RUNNING )
      {
      }
  
      // Sets a Frequency in HF band
      SX1276SetChannel( 868000000 );
  
      // Launch Rx chain calibration for HF band
      SX1276Write( REG_IMAGECAL, ( SX1276Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_MASK ) | RF_IMAGECAL_IMAGECAL_START );
      while( ( SX1276Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_RUNNING ) == RF_IMAGECAL_IMAGECAL_RUNNING )
      {
      }
  
      // Restore context
      SX1276Write( REG_PACONFIG, regPaConfigInitVal );
      SX1276SetChannel( initialFreq );
  }
  
  /*!
   * Returns the known FSK bandwidth registers value
   *
   * \param [IN] bandwidth Bandwidth value in Hz
   * \retval regValue Bandwidth register value.
   */
  static uint8_t GetFskBandwidthRegValue( uint32_t bandwidth )
  {
      uint8_t i;
  
      for( i = 0; i < ( sizeof( FskBandwidths ) / sizeof( FskBandwidth_t ) ) - 1; i++ )
      {
          if( ( bandwidth >= FskBandwidths[i].bandwidth ) && ( bandwidth < FskBandwidths[i + 1].bandwidth ) )
          {
              return FskBandwidths[i].RegValue;
          }
      }
      // ERROR: Value not found
      while( 1 );
  }
  
  void SX1276SetRxConfig( RadioModems_t modem, uint32_t bandwidth,
                           uint32_t datarate, uint8_t coderate,
                           uint32_t bandwidthAfc, uint16_t preambleLen,
                           uint16_t symbTimeout, bool fixLen,
                           uint8_t payloadLen,
                           bool crcOn, bool freqHopOn, uint8_t hopPeriod,
                           bool iqInverted, bool rxContinuous )
  {
      SX1276SetModem( modem );
  
      switch( modem )
      {
      case MODEM_FSK:
          {
              SX1276.Settings.Fsk.Bandwidth = bandwidth;
              SX1276.Settings.Fsk.Datarate = datarate;
              SX1276.Settings.Fsk.BandwidthAfc = bandwidthAfc;
              SX1276.Settings.Fsk.FixLen = fixLen;
              SX1276.Settings.Fsk.PayloadLen = payloadLen;
              SX1276.Settings.Fsk.CrcOn = crcOn;
              SX1276.Settings.Fsk.IqInverted = iqInverted;
              SX1276.Settings.Fsk.RxContinuous = rxContinuous;
              SX1276.Settings.Fsk.PreambleLen = preambleLen;
              SX1276.Settings.Fsk.RxSingleTimeout = ( uint32_t )( symbTimeout * ( ( 1.0 / ( double )datarate ) * 8.0 ) * 1000 );
  
              datarate = ( uint16_t )( ( double )XTAL_FREQ / ( double )datarate );
              SX1276Write( REG_BITRATEMSB, ( uint8_t )( datarate >> 8 ) );
              SX1276Write( REG_BITRATELSB, ( uint8_t )( datarate & 0xFF ) );
  
              SX1276Write( REG_RXBW, GetFskBandwidthRegValue( bandwidth ) );
              SX1276Write( REG_AFCBW, GetFskBandwidthRegValue( bandwidthAfc ) );
  
              SX1276Write( REG_PREAMBLEMSB, ( uint8_t )( ( preambleLen >> 8 ) & 0xFF ) );
              SX1276Write( REG_PREAMBLELSB, ( uint8_t )( preambleLen & 0xFF ) );
  
              if( fixLen == 1 )
              {
                  SX1276Write( REG_PAYLOADLENGTH, payloadLen );
              }
              else
              {
                  SX1276Write( REG_PAYLOADLENGTH, 0xFF ); // Set payload length to the maximum
              }
  
              SX1276Write( REG_PACKETCONFIG1,
                           ( SX1276Read( REG_PACKETCONFIG1 ) &
                             RF_PACKETCONFIG1_CRC_MASK &
                             RF_PACKETCONFIG1_PACKETFORMAT_MASK ) |
                             ( ( fixLen == 1 ) ? RF_PACKETCONFIG1_PACKETFORMAT_FIXED : RF_PACKETCONFIG1_PACKETFORMAT_VARIABLE ) |
                             ( crcOn << 4 ) );
              SX1276Write( REG_PACKETCONFIG2, ( SX1276Read( REG_PACKETCONFIG2 ) | RF_PACKETCONFIG2_DATAMODE_PACKET ) );
          }
          break;
      case MODEM_LORA:
          {
              if( bandwidth > 2 )
              {
                  // Fatal error: When using LoRa modem only bandwidths 125, 250 and 500 kHz are supported
                  while( 1 );
              }
              bandwidth += 7;
              SX1276.Settings.LoRa.Bandwidth = bandwidth;
              SX1276.Settings.LoRa.Datarate = datarate;
              SX1276.Settings.LoRa.Coderate = coderate;
              SX1276.Settings.LoRa.PreambleLen = preambleLen;
              SX1276.Settings.LoRa.FixLen = fixLen;
              SX1276.Settings.LoRa.PayloadLen = payloadLen;
              SX1276.Settings.LoRa.CrcOn = crcOn;
              SX1276.Settings.LoRa.FreqHopOn = freqHopOn;
              SX1276.Settings.LoRa.HopPeriod = hopPeriod;
              SX1276.Settings.LoRa.IqInverted = iqInverted;
              SX1276.Settings.LoRa.RxContinuous = rxContinuous;
  
              if( datarate > 12 )
              {
                  datarate = 12;
              }
              else if( datarate < 6 )
              {
                  datarate = 6;
              }
  
              if( ( ( bandwidth == 7 ) && ( ( datarate == 11 ) || ( datarate == 12 ) ) ) ||
                  ( ( bandwidth == 8 ) && ( datarate == 12 ) ) )
              {
                  SX1276.Settings.LoRa.LowDatarateOptimize = 0x01;
              }
              else
              {
                  SX1276.Settings.LoRa.LowDatarateOptimize = 0x00;
              }
  
              SX1276Write( REG_LR_MODEMCONFIG1,
                           ( SX1276Read( REG_LR_MODEMCONFIG1 ) &
                             RFLR_MODEMCONFIG1_BW_MASK &
                             RFLR_MODEMCONFIG1_CODINGRATE_MASK &
                             RFLR_MODEMCONFIG1_IMPLICITHEADER_MASK ) |
                             ( bandwidth << 4 ) | ( coderate << 1 ) |
                             fixLen );
  
              SX1276Write( REG_LR_MODEMCONFIG2,
                           ( SX1276Read( REG_LR_MODEMCONFIG2 ) &
                             RFLR_MODEMCONFIG2_SF_MASK &
                             RFLR_MODEMCONFIG2_RXPAYLOADCRC_MASK &
                             RFLR_MODEMCONFIG2_SYMBTIMEOUTMSB_MASK ) |
                             ( datarate << 4 ) | ( crcOn << 2 ) |
                             ( ( symbTimeout >> 8 ) & ~RFLR_MODEMCONFIG2_SYMBTIMEOUTMSB_MASK ) );
  
              SX1276Write( REG_LR_MODEMCONFIG3,
                           ( SX1276Read( REG_LR_MODEMCONFIG3 ) &
                             RFLR_MODEMCONFIG3_LOWDATARATEOPTIMIZE_MASK ) |
                             ( SX1276.Settings.LoRa.LowDatarateOptimize << 3 ) );
  
              SX1276Write( REG_LR_SYMBTIMEOUTLSB, ( uint8_t )( symbTimeout & 0xFF ) );
  
              SX1276Write( REG_LR_PREAMBLEMSB, ( uint8_t )( ( preambleLen >> 8 ) & 0xFF ) );
              SX1276Write( REG_LR_PREAMBLELSB, ( uint8_t )( preambleLen & 0xFF ) );
  
              if( fixLen == 1 )
              {
                  SX1276Write( REG_LR_PAYLOADLENGTH, payloadLen );
              }
  
              if( SX1276.Settings.LoRa.FreqHopOn == true )
              {
                  SX1276Write( REG_LR_PLLHOP, ( SX1276Read( REG_LR_PLLHOP ) & RFLR_PLLHOP_FASTHOP_MASK ) | RFLR_PLLHOP_FASTHOP_ON );
                  SX1276Write( REG_LR_HOPPERIOD, SX1276.Settings.LoRa.HopPeriod );
              }
  
              if( ( bandwidth == 9 ) && ( SX1276.Settings.Channel > RF_MID_BAND_THRESH ) )
              {
                  // ERRATA 2.1 - Sensitivity Optimization with a 500 kHz Bandwidth
                  SX1276Write( REG_LR_HIGHBWOPTIMIZE1, 0x02 );
                  SX1276Write( REG_LR_HIGHBWOPTIMIZE2, 0x64 );
              }
              else if( bandwidth == 9 )
              {
                  // ERRATA 2.1 - Sensitivity Optimization with a 500 kHz Bandwidth
                  SX1276Write( REG_LR_HIGHBWOPTIMIZE1, 0x02 );
                  SX1276Write( REG_LR_HIGHBWOPTIMIZE2, 0x7F );
              }
              else
              {
                  // ERRATA 2.1 - Sensitivity Optimization with a 500 kHz Bandwidth
                  SX1276Write( REG_LR_HIGHBWOPTIMIZE1, 0x03 );
              }
  
              if( datarate == 6 )
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE,
                               ( SX1276Read( REG_LR_DETECTOPTIMIZE ) &
                                 RFLR_DETECTIONOPTIMIZE_MASK ) |
                                 RFLR_DETECTIONOPTIMIZE_SF6 );
                  SX1276Write( REG_LR_DETECTIONTHRESHOLD,
                               RFLR_DETECTIONTHRESH_SF6 );
              }
              else
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE,
                               ( SX1276Read( REG_LR_DETECTOPTIMIZE ) &
                               RFLR_DETECTIONOPTIMIZE_MASK ) |
                               RFLR_DETECTIONOPTIMIZE_SF7_TO_SF12 );
                  SX1276Write( REG_LR_DETECTIONTHRESHOLD,
                               RFLR_DETECTIONTHRESH_SF7_TO_SF12 );
              }
          }
          break;
      }
  }
  
  void SX1276SetTxConfig( RadioModems_t modem, int8_t power, uint32_t fdev,
                          uint32_t bandwidth, uint32_t datarate,
                          uint8_t coderate, uint16_t preambleLen,
                          bool fixLen, bool crcOn, bool freqHopOn,
                          uint8_t hopPeriod, bool iqInverted, uint32_t timeout )
  {
      SX1276SetModem( modem );
  
      SX1276SetRfTxPower( power );
  
      switch( modem )
      {
      case MODEM_FSK:
          {
              SX1276.Settings.Fsk.Power = power;
              SX1276.Settings.Fsk.Fdev = fdev;
              SX1276.Settings.Fsk.Bandwidth = bandwidth;
              SX1276.Settings.Fsk.Datarate = datarate;
              SX1276.Settings.Fsk.PreambleLen = preambleLen;
              SX1276.Settings.Fsk.FixLen = fixLen;
              SX1276.Settings.Fsk.CrcOn = crcOn;
              SX1276.Settings.Fsk.IqInverted = iqInverted;
              SX1276.Settings.Fsk.TxTimeout = timeout;
  
              fdev = ( uint16_t )( ( double )fdev / ( double )FREQ_STEP );
              SX1276Write( REG_FDEVMSB, ( uint8_t )( fdev >> 8 ) );
              SX1276Write( REG_FDEVLSB, ( uint8_t )( fdev & 0xFF ) );
  
              datarate = ( uint16_t )( ( double )XTAL_FREQ / ( double )datarate );
              SX1276Write( REG_BITRATEMSB, ( uint8_t )( datarate >> 8 ) );
              SX1276Write( REG_BITRATELSB, ( uint8_t )( datarate & 0xFF ) );
  
              SX1276Write( REG_PREAMBLEMSB, ( preambleLen >> 8 ) & 0x00FF );
              SX1276Write( REG_PREAMBLELSB, preambleLen & 0xFF );
  
              SX1276Write( REG_PACKETCONFIG1,
                           ( SX1276Read( REG_PACKETCONFIG1 ) &
                             RF_PACKETCONFIG1_CRC_MASK &
                             RF_PACKETCONFIG1_PACKETFORMAT_MASK ) |
                             ( ( fixLen == 1 ) ? RF_PACKETCONFIG1_PACKETFORMAT_FIXED : RF_PACKETCONFIG1_PACKETFORMAT_VARIABLE ) |
                             ( crcOn << 4 ) );
              SX1276Write( REG_PACKETCONFIG2, ( SX1276Read( REG_PACKETCONFIG2 ) | RF_PACKETCONFIG2_DATAMODE_PACKET ) );
          }
          break;
      case MODEM_LORA:
          {
              SX1276.Settings.LoRa.Power = power;
              if( bandwidth > 2 )
              {
                  // Fatal error: When using LoRa modem only bandwidths 125, 250 and 500 kHz are supported
                  while( 1 );
              }
              bandwidth += 7;
              SX1276.Settings.LoRa.Bandwidth = bandwidth;
              SX1276.Settings.LoRa.Datarate = datarate;
              SX1276.Settings.LoRa.Coderate = coderate;
              SX1276.Settings.LoRa.PreambleLen = preambleLen;
              SX1276.Settings.LoRa.FixLen = fixLen;
              SX1276.Settings.LoRa.FreqHopOn = freqHopOn;
              SX1276.Settings.LoRa.HopPeriod = hopPeriod;
              SX1276.Settings.LoRa.CrcOn = crcOn;
              SX1276.Settings.LoRa.IqInverted = iqInverted;
              SX1276.Settings.LoRa.TxTimeout = timeout;
  
              if( datarate > 12 )
              {
                  datarate = 12;
              }
              else if( datarate < 6 )
              {
                  datarate = 6;
              }
              if( ( ( bandwidth == 7 ) && ( ( datarate == 11 ) || ( datarate == 12 ) ) ) ||
                  ( ( bandwidth == 8 ) && ( datarate == 12 ) ) )
              {
                  SX1276.Settings.LoRa.LowDatarateOptimize = 0x01;
              }
              else
              {
                  SX1276.Settings.LoRa.LowDatarateOptimize = 0x00;
              }
  
              if( SX1276.Settings.LoRa.FreqHopOn == true )
              {
                  SX1276Write( REG_LR_PLLHOP, ( SX1276Read( REG_LR_PLLHOP ) & RFLR_PLLHOP_FASTHOP_MASK ) | RFLR_PLLHOP_FASTHOP_ON );
                  SX1276Write( REG_LR_HOPPERIOD, SX1276.Settings.LoRa.HopPeriod );
              }
  
              SX1276Write( REG_LR_MODEMCONFIG1,
                           ( SX1276Read( REG_LR_MODEMCONFIG1 ) &
                             RFLR_MODEMCONFIG1_BW_MASK &
                             RFLR_MODEMCONFIG1_CODINGRATE_MASK &
                             RFLR_MODEMCONFIG1_IMPLICITHEADER_MASK ) |
                             ( bandwidth << 4 ) | ( coderate << 1 ) |
                             fixLen );
  
              SX1276Write( REG_LR_MODEMCONFIG2,
                           ( SX1276Read( REG_LR_MODEMCONFIG2 ) &
                             RFLR_MODEMCONFIG2_SF_MASK &
                             RFLR_MODEMCONFIG2_RXPAYLOADCRC_MASK ) |
                             ( datarate << 4 ) | ( crcOn << 2 ) );
  
              SX1276Write( REG_LR_MODEMCONFIG3,
                           ( SX1276Read( REG_LR_MODEMCONFIG3 ) &
                             RFLR_MODEMCONFIG3_LOWDATARATEOPTIMIZE_MASK ) |
                             ( SX1276.Settings.LoRa.LowDatarateOptimize << 3 ) );
  
              SX1276Write( REG_LR_PREAMBLEMSB, ( preambleLen >> 8 ) & 0x00FF );
              SX1276Write( REG_LR_PREAMBLELSB, preambleLen & 0xFF );
  
              if( datarate == 6 )
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE,
                               ( SX1276Read( REG_LR_DETECTOPTIMIZE ) &
                                 RFLR_DETECTIONOPTIMIZE_MASK ) |
                                 RFLR_DETECTIONOPTIMIZE_SF6 );
                  SX1276Write( REG_LR_DETECTIONTHRESHOLD,
                               RFLR_DETECTIONTHRESH_SF6 );
              }
              else
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE,
                               ( SX1276Read( REG_LR_DETECTOPTIMIZE ) &
                               RFLR_DETECTIONOPTIMIZE_MASK ) |
                               RFLR_DETECTIONOPTIMIZE_SF7_TO_SF12 );
                  SX1276Write( REG_LR_DETECTIONTHRESHOLD,
                               RFLR_DETECTIONTHRESH_SF7_TO_SF12 );
              }
          }
          break;
      }
  }
  
  uint32_t SX1276GetTimeOnAir( RadioModems_t modem, uint8_t pktLen )
  {
      uint32_t airTime = 0;
  
      switch( modem )
      {
      case MODEM_FSK:
          {
              airTime = round( ( 8 * ( SX1276.Settings.Fsk.PreambleLen +
                                       ( ( SX1276Read( REG_SYNCCONFIG ) & ~RF_SYNCCONFIG_SYNCSIZE_MASK ) + 1 ) +
                                       ( ( SX1276.Settings.Fsk.FixLen == 0x01 ) ? 0.0 : 1.0 ) +
                                       ( ( ( SX1276Read( REG_PACKETCONFIG1 ) & ~RF_PACKETCONFIG1_ADDRSFILTERING_MASK ) != 0x00 ) ? 1.0 : 0 ) +
                                       pktLen +
                                       ( ( SX1276.Settings.Fsk.CrcOn == 0x01 ) ? 2.0 : 0 ) ) /
                                       SX1276.Settings.Fsk.Datarate ) * 1000 );
          }
          break;
      case MODEM_LORA:
          {
              double bw = 0.0;
              // REMARK: When using LoRa modem only bandwidths 125, 250 and 500 kHz are supported
              switch( SX1276.Settings.LoRa.Bandwidth )
              {
              //case 0: // 7.8 kHz
              //    bw = 7800;
              //    break;
              //case 1: // 10.4 kHz
              //    bw = 10400;
              //    break;
              //case 2: // 15.6 kHz
              //    bw = 15600;
              //    break;
              //case 3: // 20.8 kHz
              //    bw = 20800;
              //    break;
              //case 4: // 31.2 kHz
              //    bw = 31200;
              //    break;
              //case 5: // 41.4 kHz
              //    bw = 41400;
              //    break;
              //case 6: // 62.5 kHz
              //    bw = 62500;
              //    break;
              case 7: // 125 kHz
                  bw = 125000;
                  break;
              case 8: // 250 kHz
                  bw = 250000;
                  break;
              case 9: // 500 kHz
                  bw = 500000;
                  break;
              }
  
              // Symbol rate : time for one symbol (secs)
              double rs = bw / ( 1 << SX1276.Settings.LoRa.Datarate );
              double ts = 1 / rs;
              // time of preamble
              double tPreamble = ( SX1276.Settings.LoRa.PreambleLen + 4.25 ) * ts;
              // Symbol length of payload and time
              double tmp = ceil( ( 8 * pktLen - 4 * SX1276.Settings.LoRa.Datarate +
                                   28 + 16 * SX1276.Settings.LoRa.CrcOn -
                                   ( SX1276.Settings.LoRa.FixLen ? 20 : 0 ) ) /
                                   ( double )( 4 * ( SX1276.Settings.LoRa.Datarate -
                                   ( ( SX1276.Settings.LoRa.LowDatarateOptimize > 0 ) ? 2 : 0 ) ) ) ) *
                                   ( SX1276.Settings.LoRa.Coderate + 4 );
              double nPayload = 8 + ( ( tmp > 0 ) ? tmp : 0 );
              double tPayload = nPayload * ts;
              // Time on air
              double tOnAir = tPreamble + tPayload;
              // return ms secs
              airTime = floor( tOnAir * 1000 + 0.999 );
          }
          break;
      }
      return airTime;
  }
  
  void SX1276Send( uint8_t *buffer, uint8_t size )
  {
      uint32_t txTimeout = 0;
  
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          {
              SX1276.Settings.FskPacketHandler.NbBytes = 0;
              SX1276.Settings.FskPacketHandler.Size = size;
  
              if( SX1276.Settings.Fsk.FixLen == false )
              {
                  SX1276WriteFifo( ( uint8_t* )&size, 1 );
              }
              else
              {
                  SX1276Write( REG_PAYLOADLENGTH, size );
              }
  
              if( ( size > 0 ) && ( size <= 64 ) )
              {
                  SX1276.Settings.FskPacketHandler.ChunkSize = size;
              }
              else
              {
                  memcpy1( RxTxBuffer, buffer, size );
                  SX1276.Settings.FskPacketHandler.ChunkSize = 32;
              }
  
              // Write payload buffer
              SX1276WriteFifo( buffer, SX1276.Settings.FskPacketHandler.ChunkSize );
              SX1276.Settings.FskPacketHandler.NbBytes += SX1276.Settings.FskPacketHandler.ChunkSize;
              txTimeout = SX1276.Settings.Fsk.TxTimeout;
          }
          break;
      case MODEM_LORA:
          {
              if( SX1276.Settings.LoRa.IqInverted == true )
              {
                  SX1276Write( REG_LR_INVERTIQ, ( ( SX1276Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_ON ) );
                  SX1276Write( REG_LR_INVERTIQ2, RFLR_INVERTIQ2_ON );
              }
              else
              {
                  SX1276Write( REG_LR_INVERTIQ, ( ( SX1276Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_OFF ) );
                  SX1276Write( REG_LR_INVERTIQ2, RFLR_INVERTIQ2_OFF );
              }
  
              SX1276.Settings.LoRaPacketHandler.Size = size;
  
              // Initializes the payload size
              SX1276Write( REG_LR_PAYLOADLENGTH, size );
  
              // Full buffer used for Tx
              SX1276Write( REG_LR_FIFOTXBASEADDR, 0 );
              SX1276Write( REG_LR_FIFOADDRPTR, 0 );
  
              // FIFO operations can not take place in Sleep mode
              if( ( SX1276Read( REG_OPMODE ) & ~RF_OPMODE_MASK ) == RF_OPMODE_SLEEP )
              {
                  SX1276SetStby( );
                  DelayMs( 1 );
              }
              // Write payload buffer
              SX1276WriteFifo( buffer, size );
              txTimeout = SX1276.Settings.LoRa.TxTimeout;
          }
          break;
      }
  
      SX1276SetTx( txTimeout );
  }
  
  void SX1276SetSleep( void )
  {
      TimerStop( &RxTimeoutTimer );
      TimerStop( &TxTimeoutTimer );
      TimerStop( &RxTimeoutSyncWord );
  
      SX1276SetOpMode( RF_OPMODE_SLEEP );
  
      // Disable TCXO radio is in SLEEP mode
      SX1276SetBoardTcxo( false );
  
      SX1276.Settings.State = RF_IDLE;
  }
  
  void SX1276SetStby( void )
  {
      TimerStop( &RxTimeoutTimer );
      TimerStop( &TxTimeoutTimer );
      TimerStop( &RxTimeoutSyncWord );
  
      SX1276SetOpMode( RF_OPMODE_STANDBY );
      SX1276.Settings.State = RF_IDLE;
  }
  
  void SX1276SetRx( uint32_t timeout )
  {
      bool rxContinuous = false;
      TimerStop( &TxTimeoutTimer );
  
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          {
              rxContinuous = SX1276.Settings.Fsk.RxContinuous;
  
              // DIO0=PayloadReady
              // DIO1=FifoLevel
              // DIO2=SyncAddr
              // DIO3=FifoEmpty
              // DIO4=Preamble
              // DIO5=ModeReady
              SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RF_DIOMAPPING1_DIO0_MASK &
                                                                              RF_DIOMAPPING1_DIO1_MASK &
                                                                              RF_DIOMAPPING1_DIO2_MASK ) |
                                                                              RF_DIOMAPPING1_DIO0_00 |
                                                                              RF_DIOMAPPING1_DIO1_00 |
                                                                              RF_DIOMAPPING1_DIO2_11 );
  
              SX1276Write( REG_DIOMAPPING2, ( SX1276Read( REG_DIOMAPPING2 ) & RF_DIOMAPPING2_DIO4_MASK &
                                                                              RF_DIOMAPPING2_MAP_MASK ) |
                                                                              RF_DIOMAPPING2_DIO4_11 |
                                                                              RF_DIOMAPPING2_MAP_PREAMBLEDETECT );
  
              SX1276.Settings.FskPacketHandler.FifoThresh = SX1276Read( REG_FIFOTHRESH ) & 0x3F;
  
              SX1276Write( REG_RXCONFIG, RF_RXCONFIG_AFCAUTO_ON | RF_RXCONFIG_AGCAUTO_ON | RF_RXCONFIG_RXTRIGER_PREAMBLEDETECT );
  
              SX1276.Settings.FskPacketHandler.PreambleDetected = false;
              SX1276.Settings.FskPacketHandler.SyncWordDetected = false;
              SX1276.Settings.FskPacketHandler.NbBytes = 0;
              SX1276.Settings.FskPacketHandler.Size = 0;
          }
          break;
      case MODEM_LORA:
          {
              if( SX1276.Settings.LoRa.IqInverted == true )
              {
                  SX1276Write( REG_LR_INVERTIQ, ( ( SX1276Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_ON | RFLR_INVERTIQ_TX_OFF ) );
                  SX1276Write( REG_LR_INVERTIQ2, RFLR_INVERTIQ2_ON );
              }
              else
              {
                  SX1276Write( REG_LR_INVERTIQ, ( ( SX1276Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_OFF ) );
                  SX1276Write( REG_LR_INVERTIQ2, RFLR_INVERTIQ2_OFF );
              }
  
              // ERRATA 2.3 - Receiver Spurious Reception of a LoRa Signal
              if( SX1276.Settings.LoRa.Bandwidth < 9 )
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE, SX1276Read( REG_LR_DETECTOPTIMIZE ) & 0x7F );
                  SX1276Write( REG_LR_IFFREQ2, 0x00 );
                  switch( SX1276.Settings.LoRa.Bandwidth )
                  {
                  case 0: // 7.8 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x48 );
                      SX1276SetChannel(SX1276.Settings.Channel + 7810 );
                      break;
                  case 1: // 10.4 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x44 );
                      SX1276SetChannel(SX1276.Settings.Channel + 10420 );
                      break;
                  case 2: // 15.6 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x44 );
                      SX1276SetChannel(SX1276.Settings.Channel + 15620 );
                      break;
                  case 3: // 20.8 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x44 );
                      SX1276SetChannel(SX1276.Settings.Channel + 20830 );
                      break;
                  case 4: // 31.2 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x44 );
                      SX1276SetChannel(SX1276.Settings.Channel + 31250 );
                      break;
                  case 5: // 41.4 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x44 );
                      SX1276SetChannel(SX1276.Settings.Channel + 41670 );
                      break;
                  case 6: // 62.5 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x40 );
                      break;
                  case 7: // 125 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x40 );
                      break;
                  case 8: // 250 kHz
                      SX1276Write( REG_LR_IFFREQ1, 0x40 );
                      break;
                  }
              }
              else
              {
                  SX1276Write( REG_LR_DETECTOPTIMIZE, SX1276Read( REG_LR_DETECTOPTIMIZE ) | 0x80 );
              }
  
              rxContinuous = SX1276.Settings.LoRa.RxContinuous;
  
              if( SX1276.Settings.LoRa.FreqHopOn == true )
              {
                  SX1276Write( REG_LR_IRQFLAGSMASK, //RFLR_IRQFLAGS_RXTIMEOUT |
                                                    //RFLR_IRQFLAGS_RXDONE |
                                                    //RFLR_IRQFLAGS_PAYLOADCRCERROR |
                                                    RFLR_IRQFLAGS_VALIDHEADER |
                                                    RFLR_IRQFLAGS_TXDONE |
                                                    RFLR_IRQFLAGS_CADDONE |
                                                    //RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL |
                                                    RFLR_IRQFLAGS_CADDETECTED );
  
                  // DIO0=RxDone, DIO2=FhssChangeChannel
                  SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK & RFLR_DIOMAPPING1_DIO2_MASK  ) | RFLR_DIOMAPPING1_DIO0_00 | RFLR_DIOMAPPING1_DIO2_00 );
              }
              else
              {
                  SX1276Write( REG_LR_IRQFLAGSMASK, //RFLR_IRQFLAGS_RXTIMEOUT |
                                                    //RFLR_IRQFLAGS_RXDONE |
                                                    //RFLR_IRQFLAGS_PAYLOADCRCERROR |
                                                    RFLR_IRQFLAGS_VALIDHEADER |
                                                    RFLR_IRQFLAGS_TXDONE |
                                                    RFLR_IRQFLAGS_CADDONE |
                                                    RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL |
                                                    RFLR_IRQFLAGS_CADDETECTED );
  
                  // DIO0=RxDone
                  SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_00 );
              }
              SX1276Write( REG_LR_FIFORXBASEADDR, 0 );
              SX1276Write( REG_LR_FIFOADDRPTR, 0 );
          }
          break;
      }
  
      memset( RxTxBuffer, 0, ( size_t )RX_BUFFER_SIZE );
  
      SX1276.Settings.State = RF_RX_RUNNING;
      if( timeout != 0 )
      {
          TimerSetValue( &RxTimeoutTimer, timeout );
          TimerStart( &RxTimeoutTimer );
      }
  
      if( SX1276.Settings.Modem == MODEM_FSK )
      {
          SX1276SetOpMode( RF_OPMODE_RECEIVER );
  
          TimerSetValue( &RxTimeoutSyncWord, SX1276.Settings.Fsk.RxSingleTimeout );
          TimerStart( &RxTimeoutSyncWord );
      }
      else
      {
          if( rxContinuous == true )
          {
              SX1276SetOpMode( RFLR_OPMODE_RECEIVER );
          }
          else
          {
              SX1276SetOpMode( RFLR_OPMODE_RECEIVER_SINGLE );
          }
      }
  }
  
  void SX1276SetTx( uint32_t timeout )
  {
      TimerStop( &RxTimeoutTimer );
  
      TimerSetValue( &TxTimeoutTimer, timeout );
  
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          {
              // DIO0=PacketSent
              // DIO1=FifoEmpty
              // DIO2=FifoFull
              // DIO3=FifoEmpty
              // DIO4=LowBat
              // DIO5=ModeReady
              SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RF_DIOMAPPING1_DIO0_MASK &
                                                                              RF_DIOMAPPING1_DIO1_MASK &
                                                                              RF_DIOMAPPING1_DIO2_MASK ) |
                                                                              RF_DIOMAPPING1_DIO1_01 );
  
              SX1276Write( REG_DIOMAPPING2, ( SX1276Read( REG_DIOMAPPING2 ) & RF_DIOMAPPING2_DIO4_MASK &
                                                                              RF_DIOMAPPING2_MAP_MASK ) );
              SX1276.Settings.FskPacketHandler.FifoThresh = SX1276Read( REG_FIFOTHRESH ) & 0x3F;
          }
          break;
      case MODEM_LORA:
          {
              if( SX1276.Settings.LoRa.FreqHopOn == true )
              {
                  SX1276Write( REG_LR_IRQFLAGSMASK, RFLR_IRQFLAGS_RXTIMEOUT |
                                                    RFLR_IRQFLAGS_RXDONE |
                                                    RFLR_IRQFLAGS_PAYLOADCRCERROR |
                                                    RFLR_IRQFLAGS_VALIDHEADER |
                                                    //RFLR_IRQFLAGS_TXDONE |
                                                    RFLR_IRQFLAGS_CADDONE |
                                                    //RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL |
                                                    RFLR_IRQFLAGS_CADDETECTED );
  
                  // DIO0=TxDone, DIO2=FhssChangeChannel
                  SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK & RFLR_DIOMAPPING1_DIO2_MASK ) | RFLR_DIOMAPPING1_DIO0_01 | RFLR_DIOMAPPING1_DIO2_00 );
              }
              else
              {
                  SX1276Write( REG_LR_IRQFLAGSMASK, RFLR_IRQFLAGS_RXTIMEOUT |
                                                    RFLR_IRQFLAGS_RXDONE |
                                                    RFLR_IRQFLAGS_PAYLOADCRCERROR |
                                                    RFLR_IRQFLAGS_VALIDHEADER |
                                                    //RFLR_IRQFLAGS_TXDONE |
                                                    RFLR_IRQFLAGS_CADDONE |
                                                    RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL |
                                                    RFLR_IRQFLAGS_CADDETECTED );
  
                  // DIO0=TxDone
                  SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_01 );
              }
          }
          break;
      }
  
      SX1276.Settings.State = RF_TX_RUNNING;
      TimerStart( &TxTimeoutTimer );
      SX1276SetOpMode( RF_OPMODE_TRANSMITTER );
  }
  
  void SX1276StartCad( void )
  {
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          {
  
          }
          break;
      case MODEM_LORA:
          {
              SX1276Write( REG_LR_IRQFLAGSMASK, RFLR_IRQFLAGS_RXTIMEOUT |
                                          RFLR_IRQFLAGS_RXDONE |
                                          RFLR_IRQFLAGS_PAYLOADCRCERROR |
                                          RFLR_IRQFLAGS_VALIDHEADER |
                                          RFLR_IRQFLAGS_TXDONE |
                                          //RFLR_IRQFLAGS_CADDONE |
                                          RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL // |
                                          //RFLR_IRQFLAGS_CADDETECTED
                                          );
  
              // DIO3=CADDone
              SX1276Write( REG_DIOMAPPING1, ( SX1276Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO3_MASK ) | RFLR_DIOMAPPING1_DIO3_00 );
  
              SX1276.Settings.State = RF_CAD;
              SX1276SetOpMode( RFLR_OPMODE_CAD );
          }
          break;
      default:
          break;
      }
  }
  
  void SX1276SetTxContinuousWave( uint32_t freq, int8_t power, uint16_t time )
  {
      uint32_t timeout = ( uint32_t )( time * 1000 );
  
      SX1276SetChannel( freq );
  
      SX1276SetTxConfig( MODEM_FSK, power, 0, 0, 4800, 0, 5, false, false, 0, 0, 0, timeout );
  
      SX1276Write( REG_PACKETCONFIG2, ( SX1276Read( REG_PACKETCONFIG2 ) & RF_PACKETCONFIG2_DATAMODE_MASK ) );
      // Disable radio interrupts
      SX1276Write( REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_11 | RF_DIOMAPPING1_DIO1_11 );
      SX1276Write( REG_DIOMAPPING2, RF_DIOMAPPING2_DIO4_10 | RF_DIOMAPPING2_DIO5_10 );
  
      TimerSetValue( &TxTimeoutTimer, timeout );
  
      SX1276.Settings.State = RF_TX_RUNNING;
      TimerStart( &TxTimeoutTimer );
      SX1276SetOpMode( RF_OPMODE_TRANSMITTER );
  }
  
  int16_t SX1276ReadRssi( RadioModems_t modem )
  {
      int16_t rssi = 0;
  
      switch( modem )
      {
      case MODEM_FSK:
          rssi = -( SX1276Read( REG_RSSIVALUE ) >> 1 );
          break;
      case MODEM_LORA:
          if( SX1276.Settings.Channel > RF_MID_BAND_THRESH )
          {
              rssi = RSSI_OFFSET_HF + SX1276Read( REG_LR_RSSIVALUE );
          }
          else
          {
              rssi = RSSI_OFFSET_LF + SX1276Read( REG_LR_RSSIVALUE );
          }
          break;
      default:
          rssi = -1;
          break;
      }
      return rssi;
  }
  
  void SX1276SetOpMode( uint8_t opMode )
  {
  #if defined( USE_RADIO_DEBUG )
      switch( opMode )
      {
          case RF_OPMODE_TRANSMITTER:
              SX1276DbgPinTxWrite( 1 );
              SX1276DbgPinRxWrite( 0 );
              break;
          case RF_OPMODE_RECEIVER:
          case RFLR_OPMODE_RECEIVER_SINGLE:
              SX1276DbgPinTxWrite( 0 );
              SX1276DbgPinRxWrite( 1 );
              break;
          default:
              SX1276DbgPinTxWrite( 0 );
              SX1276DbgPinRxWrite( 0 );
              break;
      }
  #endif
      if( opMode == RF_OPMODE_SLEEP )
      {
          SX1276SetAntSwLowPower( true );
      }
      else
      {
          // Enable TCXO if operating mode different from SLEEP.
          SX1276SetBoardTcxo( true );
          SX1276SetAntSwLowPower( false );
          SX1276SetAntSw( opMode );
      }
      SX1276Write( REG_OPMODE, ( SX1276Read( REG_OPMODE ) & RF_OPMODE_MASK ) | opMode );
  }
  
  void SX1276SetModem( RadioModems_t modem )
  {
      if( ( SX1276Read( REG_OPMODE ) & RFLR_OPMODE_LONGRANGEMODE_ON ) != 0 )
      {
          SX1276.Settings.Modem = MODEM_LORA;
      }
      else
      {
          SX1276.Settings.Modem = MODEM_FSK;
      }
  
      if( SX1276.Settings.Modem == modem )
      {
          return;
      }
  
      SX1276.Settings.Modem = modem;
      switch( SX1276.Settings.Modem )
      {
      default:
      case MODEM_FSK:
          SX1276SetOpMode( RF_OPMODE_SLEEP );
          SX1276Write( REG_OPMODE, ( SX1276Read( REG_OPMODE ) & RFLR_OPMODE_LONGRANGEMODE_MASK ) | RFLR_OPMODE_LONGRANGEMODE_OFF );
  
          SX1276Write( REG_DIOMAPPING1, 0x00 );
          SX1276Write( REG_DIOMAPPING2, 0x30 ); // DIO5=ModeReady
          break;
      case MODEM_LORA:
          SX1276SetOpMode( RF_OPMODE_SLEEP );
          SX1276Write( REG_OPMODE, ( SX1276Read( REG_OPMODE ) & RFLR_OPMODE_LONGRANGEMODE_MASK ) | RFLR_OPMODE_LONGRANGEMODE_ON );
  
          SX1276Write( REG_DIOMAPPING1, 0x00 );
          SX1276Write( REG_DIOMAPPING2, 0x00 );
          break;
      }
  }
  
  void SX1276Write( uint16_t addr, uint8_t data )
  {
      SX1276WriteBuffer( addr, &data, 1 );
  }
  
  uint8_t SX1276Read( uint16_t addr )
  {
      uint8_t data;
      SX1276ReadBuffer( addr, &data, 1 );
      return data;
  }
  
  void SX1276WriteBuffer( uint16_t addr, uint8_t *buffer, uint8_t size )
  {
      uint8_t i;
  
      //NSS = 0;
      GpioWrite( &SX1276.Spi.Nss, 0 );
  
      SpiInOut( &SX1276.Spi, addr | 0x80 );
      for( i = 0; i < size; i++ )
      {
          SpiInOut( &SX1276.Spi, buffer[i] );
      }
  
      //NSS = 1;
      GpioWrite( &SX1276.Spi.Nss, 1 );
  }
  
  void SX1276ReadBuffer( uint16_t addr, uint8_t *buffer, uint8_t size )
  {
      uint8_t i;
  
      //NSS = 0;
      GpioWrite( &SX1276.Spi.Nss, 0 );
  
      SpiInOut( &SX1276.Spi, addr & 0x7F );
  
      for( i = 0; i < size; i++ )
      {
          buffer[i] = SpiInOut( &SX1276.Spi, 0 );
      }
  
      //NSS = 1;
      GpioWrite( &SX1276.Spi.Nss, 1 );
  }
  
  void SX1276WriteFifo( uint8_t *buffer, uint8_t size )
  {
      SX1276WriteBuffer( 0, buffer, size );
  }
  
  void SX1276ReadFifo( uint8_t *buffer, uint8_t size )
  {
      SX1276ReadBuffer( 0, buffer, size );
  }
  
  void SX1276SetMaxPayloadLength( RadioModems_t modem, uint8_t max )
  {
      SX1276SetModem( modem );
  
      switch( modem )
      {
      case MODEM_FSK:
          if( SX1276.Settings.Fsk.FixLen == false )
          {
              SX1276Write( REG_PAYLOADLENGTH, max );
          }
          break;
      case MODEM_LORA:
          SX1276Write( REG_LR_PAYLOADMAXLENGTH, max );
          break;
      }
  }
  
  void SX1276SetPublicNetwork( bool enable )
  {
      SX1276SetModem( MODEM_LORA );
      SX1276.Settings.LoRa.PublicNetwork = enable;
      if( enable == true )
      {
          // Change LoRa modem SyncWord
          SX1276Write( REG_LR_SYNCWORD, LORA_MAC_PUBLIC_SYNCWORD );
      }
      else
      {
          // Change LoRa modem SyncWord
          SX1276Write( REG_LR_SYNCWORD, LORA_MAC_PRIVATE_SYNCWORD );
      }
  }
  
  uint32_t SX1276GetWakeupTime( void )
  {
      return SX1276GetBoardTcxoWakeupTime( ) + RADIO_WAKEUP_TIME;
  }
  
  void SX1276OnTimeoutIrq( void* context )
  {
      switch( SX1276.Settings.State )
      {
      case RF_RX_RUNNING:
          if( SX1276.Settings.Modem == MODEM_FSK )
          {
              SX1276.Settings.FskPacketHandler.PreambleDetected = false;
              SX1276.Settings.FskPacketHandler.SyncWordDetected = false;
              SX1276.Settings.FskPacketHandler.NbBytes = 0;
              SX1276.Settings.FskPacketHandler.Size = 0;
  
              // Clear Irqs
              SX1276Write( REG_IRQFLAGS1, RF_IRQFLAGS1_RSSI |
                                          RF_IRQFLAGS1_PREAMBLEDETECT |
                                          RF_IRQFLAGS1_SYNCADDRESSMATCH );
              SX1276Write( REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN );
  
              if( SX1276.Settings.Fsk.RxContinuous == true )
              {
                  // Continuous mode restart Rx chain
                  SX1276Write( REG_RXCONFIG, SX1276Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
                  TimerStart( &RxTimeoutSyncWord );
              }
              else
              {
                  SX1276.Settings.State = RF_IDLE;
                  TimerStop( &RxTimeoutSyncWord );
              }
          }
          if( ( RadioEvents != NULL ) && ( RadioEvents->RxTimeout != NULL ) )
          {
              RadioEvents->RxTimeout( );
          }
          break;
      case RF_TX_RUNNING:
          // Tx timeout shouldn't happen.
          // Reported issue of SPI data corruption resulting in TX TIMEOUT 
          // is NOT related to a bug in radio transceiver.
          // It is mainly caused by improper PCB routing of SPI lines and/or
          // violation of SPI specifications.
          // To mitigate redesign, Semtech offers a workaround which resets
          // the radio transceiver and putting it into a known state.
  
          // BEGIN WORKAROUND
  
          // Reset the radio
          SX1276Reset( );
  
          // Calibrate Rx chain
          RxChainCalibration( );
  
          // Initialize radio default values
          SX1276SetOpMode( RF_OPMODE_SLEEP );
  
          for( uint8_t i = 0; i < sizeof( RadioRegsInit ) / sizeof( RadioRegisters_t ); i++ )
          {
              SX1276SetModem( RadioRegsInit[i].Modem );
              SX1276Write( RadioRegsInit[i].Addr, RadioRegsInit[i].Value );
          }
          SX1276SetModem( MODEM_FSK );
  
          // Restore previous network type setting.
          SX1276SetPublicNetwork( SX1276.Settings.LoRa.PublicNetwork );
          // END WORKAROUND
  
          SX1276.Settings.State = RF_IDLE;
          if( ( RadioEvents != NULL ) && ( RadioEvents->TxTimeout != NULL ) )
          {
              RadioEvents->TxTimeout( );
          }
          break;
      default:
          break;
      }
  }
  
  void SX1276OnDio0Irq( void* context )
  {
      volatile uint8_t irqFlags = 0;
  
      switch( SX1276.Settings.State )
      {
          case RF_RX_RUNNING:
              //TimerStop( &RxTimeoutTimer );
              // RxDone interrupt
              switch( SX1276.Settings.Modem )
              {
              case MODEM_FSK:
                  if( SX1276.Settings.Fsk.CrcOn == true )
                  {
                      irqFlags = SX1276Read( REG_IRQFLAGS2 );
                      if( ( irqFlags & RF_IRQFLAGS2_CRCOK ) != RF_IRQFLAGS2_CRCOK )
                      {
                          // Clear Irqs
                          SX1276Write( REG_IRQFLAGS1, RF_IRQFLAGS1_RSSI |
                                                      RF_IRQFLAGS1_PREAMBLEDETECT |
                                                      RF_IRQFLAGS1_SYNCADDRESSMATCH );
                          SX1276Write( REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN );
  
                          TimerStop( &RxTimeoutTimer );
  
                          if( SX1276.Settings.Fsk.RxContinuous == false )
                          {
                              TimerStop( &RxTimeoutSyncWord );
                              SX1276.Settings.State = RF_IDLE;
                          }
                          else
                          {
                              // Continuous mode restart Rx chain
                              SX1276Write( REG_RXCONFIG, SX1276Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
                              TimerStart( &RxTimeoutSyncWord );
                          }
  
                          if( ( RadioEvents != NULL ) && ( RadioEvents->RxError != NULL ) )
                          {
                              RadioEvents->RxError( );
                          }
                          SX1276.Settings.FskPacketHandler.PreambleDetected = false;
                          SX1276.Settings.FskPacketHandler.SyncWordDetected = false;
                          SX1276.Settings.FskPacketHandler.NbBytes = 0;
                          SX1276.Settings.FskPacketHandler.Size = 0;
                          break;
                      }
                  }
  
                  // Read received packet size
                  if( ( SX1276.Settings.FskPacketHandler.Size == 0 ) && ( SX1276.Settings.FskPacketHandler.NbBytes == 0 ) )
                  {
                      if( SX1276.Settings.Fsk.FixLen == false )
                      {
                          SX1276ReadFifo( ( uint8_t* )&SX1276.Settings.FskPacketHandler.Size, 1 );
                      }
                      else
                      {
                          SX1276.Settings.FskPacketHandler.Size = SX1276Read( REG_PAYLOADLENGTH );
                      }
                      SX1276ReadFifo( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes, SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                      SX1276.Settings.FskPacketHandler.NbBytes += ( SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                  }
                  else
                  {
                      SX1276ReadFifo( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes, SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                      SX1276.Settings.FskPacketHandler.NbBytes += ( SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                  }
  
                  TimerStop( &RxTimeoutTimer );
  
                  if( SX1276.Settings.Fsk.RxContinuous == false )
                  {
                      SX1276.Settings.State = RF_IDLE;
                      TimerStop( &RxTimeoutSyncWord );
                  }
                  else
                  {
                      // Continuous mode restart Rx chain
                      SX1276Write( REG_RXCONFIG, SX1276Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
                      TimerStart( &RxTimeoutSyncWord );
                  }
  
                  if( ( RadioEvents != NULL ) && ( RadioEvents->RxDone != NULL ) )
                  {
                      RadioEvents->RxDone( RxTxBuffer, SX1276.Settings.FskPacketHandler.Size, SX1276.Settings.FskPacketHandler.RssiValue, 0 );
                  }
                  SX1276.Settings.FskPacketHandler.PreambleDetected = false;
                  SX1276.Settings.FskPacketHandler.SyncWordDetected = false;
                  SX1276.Settings.FskPacketHandler.NbBytes = 0;
                  SX1276.Settings.FskPacketHandler.Size = 0;
                  break;
              case MODEM_LORA:
                  {
                      // Clear Irq
                      SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_RXDONE );
  
                      irqFlags = SX1276Read( REG_LR_IRQFLAGS );
                      if( ( irqFlags & RFLR_IRQFLAGS_PAYLOADCRCERROR_MASK ) == RFLR_IRQFLAGS_PAYLOADCRCERROR )
                      {
                          // Clear Irq
                          SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_PAYLOADCRCERROR );
  
                          if( SX1276.Settings.LoRa.RxContinuous == false )
                          {
                              SX1276.Settings.State = RF_IDLE;
                          }
                          TimerStop( &RxTimeoutTimer );
  
                          if( ( RadioEvents != NULL ) && ( RadioEvents->RxError != NULL ) )
                          {
                              RadioEvents->RxError( );
                          }
                          break;
                      }
  
                      // Returns SNR value [dB] rounded to the nearest integer value
                      SX1276.Settings.LoRaPacketHandler.SnrValue = ( ( ( int8_t )SX1276Read( REG_LR_PKTSNRVALUE ) ) + 2 ) >> 2;
  
                      int16_t rssi = SX1276Read( REG_LR_PKTRSSIVALUE );
                      if( SX1276.Settings.LoRaPacketHandler.SnrValue < 0 )
                      {
                          if( SX1276.Settings.Channel > RF_MID_BAND_THRESH )
                          {
                              SX1276.Settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_HF + rssi + ( rssi >> 4 ) +
                                                                            SX1276.Settings.LoRaPacketHandler.SnrValue;
                          }
                          else
                          {
                              SX1276.Settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_LF + rssi + ( rssi >> 4 ) +
                                                                            SX1276.Settings.LoRaPacketHandler.SnrValue;
                          }
                      }
                      else
                      {
                          if( SX1276.Settings.Channel > RF_MID_BAND_THRESH )
                          {
                              SX1276.Settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_HF + rssi + ( rssi >> 4 );
                          }
                          else
                          {
                              SX1276.Settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_LF + rssi + ( rssi >> 4 );
                          }
                      }
  
                      SX1276.Settings.LoRaPacketHandler.Size = SX1276Read( REG_LR_RXNBBYTES );
                      SX1276Write( REG_LR_FIFOADDRPTR, SX1276Read( REG_LR_FIFORXCURRENTADDR ) );
                      SX1276ReadFifo( RxTxBuffer, SX1276.Settings.LoRaPacketHandler.Size );
  
                      if( SX1276.Settings.LoRa.RxContinuous == false )
                      {
                          SX1276.Settings.State = RF_IDLE;
                      }
                      TimerStop( &RxTimeoutTimer );
  
                      if( ( RadioEvents != NULL ) && ( RadioEvents->RxDone != NULL ) )
                      {
                          RadioEvents->RxDone( RxTxBuffer, SX1276.Settings.LoRaPacketHandler.Size, SX1276.Settings.LoRaPacketHandler.RssiValue, SX1276.Settings.LoRaPacketHandler.SnrValue );
                      }
                  }
                  break;
              default:
                  break;
              }
              break;
          case RF_TX_RUNNING:
              TimerStop( &TxTimeoutTimer );
              // TxDone interrupt
              switch( SX1276.Settings.Modem )
              {
              case MODEM_LORA:
                  // Clear Irq
                  SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_TXDONE );
                  // Intentional fall through
              case MODEM_FSK:
              default:
                  SX1276.Settings.State = RF_IDLE;
                  if( ( RadioEvents != NULL ) && ( RadioEvents->TxDone != NULL ) )
                  {
                      RadioEvents->TxDone( );
                  }
                  break;
              }
              break;
          default:
              break;
      }
  }
  
  void SX1276OnDio1Irq( void* context )
  {
      switch( SX1276.Settings.State )
      {
          case RF_RX_RUNNING:
              switch( SX1276.Settings.Modem )
              {
              case MODEM_FSK:
                  // Stop timer
                  TimerStop( &RxTimeoutSyncWord );
  
                  // FifoLevel interrupt
                  // Read received packet size
                  if( ( SX1276.Settings.FskPacketHandler.Size == 0 ) && ( SX1276.Settings.FskPacketHandler.NbBytes == 0 ) )
                  {
                      if( SX1276.Settings.Fsk.FixLen == false )
                      {
                          SX1276ReadFifo( ( uint8_t* )&SX1276.Settings.FskPacketHandler.Size, 1 );
                      }
                      else
                      {
                          SX1276.Settings.FskPacketHandler.Size = SX1276Read( REG_PAYLOADLENGTH );
                      }
                  }
  
                  // ERRATA 3.1 - PayloadReady Set for 31.25ns if FIFO is Empty
                  //
                  //              When FifoLevel interrupt is used to offload the
                  //              FIFO, the microcontroller should  monitor  both
                  //              PayloadReady  and FifoLevel interrupts, and
                  //              read only (FifoThreshold-1) bytes off the FIFO
                  //              when FifoLevel fires
                  if( ( SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes ) >= SX1276.Settings.FskPacketHandler.FifoThresh )
                  {
                      SX1276ReadFifo( ( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes ), SX1276.Settings.FskPacketHandler.FifoThresh - 1 );
                      SX1276.Settings.FskPacketHandler.NbBytes += SX1276.Settings.FskPacketHandler.FifoThresh - 1;
                  }
                  else
                  {
                      SX1276ReadFifo( ( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes ), SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                      SX1276.Settings.FskPacketHandler.NbBytes += ( SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                  }
                  break;
              case MODEM_LORA:
                  // Sync time out
                  TimerStop( &RxTimeoutTimer );
                  // Clear Irq
                  SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_RXTIMEOUT );
  
                  SX1276.Settings.State = RF_IDLE;
                  if( ( RadioEvents != NULL ) && ( RadioEvents->RxTimeout != NULL ) )
                  {
                      RadioEvents->RxTimeout( );
                  }
                  break;
              default:
                  break;
              }
              break;
          case RF_TX_RUNNING:
              switch( SX1276.Settings.Modem )
              {
              case MODEM_FSK:
                  // FifoEmpty interrupt
                  if( ( SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes ) > SX1276.Settings.FskPacketHandler.ChunkSize )
                  {
                      SX1276WriteFifo( ( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes ), SX1276.Settings.FskPacketHandler.ChunkSize );
                      SX1276.Settings.FskPacketHandler.NbBytes += SX1276.Settings.FskPacketHandler.ChunkSize;
                  }
                  else
                  {
                      // Write the last chunk of data
                      SX1276WriteFifo( RxTxBuffer + SX1276.Settings.FskPacketHandler.NbBytes, SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes );
                      SX1276.Settings.FskPacketHandler.NbBytes += SX1276.Settings.FskPacketHandler.Size - SX1276.Settings.FskPacketHandler.NbBytes;
                  }
                  break;
              case MODEM_LORA:
                  break;
              default:
                  break;
              }
              break;
          default:
              break;
      }
  }
  
  void SX1276OnDio2Irq( void* context )
  {
      switch( SX1276.Settings.State )
      {
          case RF_RX_RUNNING:
              switch( SX1276.Settings.Modem )
              {
              case MODEM_FSK:
                  // Checks if DIO4 is connected. If it is not PreambleDetected is set to true.
                  if( SX1276.DIO4.port == NULL )
                  {
                      SX1276.Settings.FskPacketHandler.PreambleDetected = true;
                  }
  
                  if( ( SX1276.Settings.FskPacketHandler.PreambleDetected == true ) && ( SX1276.Settings.FskPacketHandler.SyncWordDetected == false ) )
                  {
                      TimerStop( &RxTimeoutSyncWord );
  
                      SX1276.Settings.FskPacketHandler.SyncWordDetected = true;
  
                      SX1276.Settings.FskPacketHandler.RssiValue = -( SX1276Read( REG_RSSIVALUE ) >> 1 );
  
                      SX1276.Settings.FskPacketHandler.AfcValue = ( int32_t )( double )( ( ( uint16_t )SX1276Read( REG_AFCMSB ) << 8 ) |
                                                                             ( uint16_t )SX1276Read( REG_AFCLSB ) ) *
                                                                             ( double )FREQ_STEP;
                      SX1276.Settings.FskPacketHandler.RxGain = ( SX1276Read( REG_LNA ) >> 5 ) & 0x07;
                  }
                  break;
              case MODEM_LORA:
                  if( SX1276.Settings.LoRa.FreqHopOn == true )
                  {
                      // Clear Irq
                      SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL );
  
                      if( ( RadioEvents != NULL ) && ( RadioEvents->FhssChangeChannel != NULL ) )
                      {
                          RadioEvents->FhssChangeChannel( ( SX1276Read( REG_LR_HOPCHANNEL ) & RFLR_HOPCHANNEL_CHANNEL_MASK ) );
                      }
                  }
                  break;
              default:
                  break;
              }
              break;
          case RF_TX_RUNNING:
              switch( SX1276.Settings.Modem )
              {
              case MODEM_FSK:
                  break;
              case MODEM_LORA:
                  if( SX1276.Settings.LoRa.FreqHopOn == true )
                  {
                      // Clear Irq
                      SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL );
  
                      if( ( RadioEvents != NULL ) && ( RadioEvents->FhssChangeChannel != NULL ) )
                      {
                          RadioEvents->FhssChangeChannel( ( SX1276Read( REG_LR_HOPCHANNEL ) & RFLR_HOPCHANNEL_CHANNEL_MASK ) );
                      }
                  }
                  break;
              default:
                  break;
              }
              break;
          default:
              break;
      }
  }
  
  void SX1276OnDio3Irq( void* context )
  {
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          break;
      case MODEM_LORA:
          if( ( SX1276Read( REG_LR_IRQFLAGS ) & RFLR_IRQFLAGS_CADDETECTED ) == RFLR_IRQFLAGS_CADDETECTED )
          {
              // Clear Irq
              SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_CADDETECTED | RFLR_IRQFLAGS_CADDONE );
              if( ( RadioEvents != NULL ) && ( RadioEvents->CadDone != NULL ) )
              {
                  RadioEvents->CadDone( true );
              }
          }
          else
          {
              // Clear Irq
              SX1276Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_CADDONE );
              if( ( RadioEvents != NULL ) && ( RadioEvents->CadDone != NULL ) )
              {
                  RadioEvents->CadDone( false );
              }
          }
          break;
      default:
          break;
      }
  }
  
  void SX1276OnDio4Irq( void* context )
  {
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          {
              if( SX1276.Settings.FskPacketHandler.PreambleDetected == false )
              {
                  SX1276.Settings.FskPacketHandler.PreambleDetected = true;
              }
          }
          break;
      case MODEM_LORA:
          break;
      default:
          break;
      }
  }
  
  void SX1276OnDio5Irq( void* context )
  {
      switch( SX1276.Settings.Modem )
      {
      case MODEM_FSK:
          break;
      case MODEM_LORA:
          break;
      default:
          break;
      }
  }
  