File content as of revision 20:e05596ba4166:

/*
 / _____)             _              | |
( (____  _____ ____ _| |_ _____  ____| |__
 \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 _____) ) ____| | | || |_| ____( (___| | | |
(______/|_____)_|_|_| \__)_____)\____)_| |_|
    ( C )2014 Semtech

Description: Actual implementation of a SX1276 radio, inherits Radio

License: Revised BSD License, see LICENSE.TXT file include in the project

Maintainers: Miguel Luis, Gregory Cristian and Nicolas Huguenin
*/
#include "sx1276.h"

const FskBandwidth_t SX1276::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 Badwidth
};


SX1276::SX1276( void ( *txDone )( ), void ( *txTimeout ) ( ), void ( *rxDone ) ( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr ), 
                void ( *rxTimeout ) ( ), void ( *rxError ) ( ), void ( *fhssChangeChannel ) ( uint8_t channelIndex ), void ( *cadDone ) ( bool channelActivityDetected ),
                PinName mosi, PinName miso, PinName sclk, PinName nss, PinName reset,
                PinName dio0, PinName dio1, PinName dio2, PinName dio3, PinName dio4, PinName dio5 )
            :   Radio( txDone, txTimeout, rxDone, rxTimeout, rxError, fhssChangeChannel, cadDone ),
                spi( mosi, miso, sclk ),
                nss( nss ),
                reset( reset ),
                dio0( dio0 ), dio1( dio1 ), dio2( dio2 ), dio3( dio3 ), dio4( dio4 ), dio5( dio5 ),
                isRadioActive( false )
{
    wait_ms( 10 );
    this->rxTx = 0;
    this->rxBuffer = new uint8_t[RX_BUFFER_SIZE];
    previousOpMode = RF_OPMODE_STANDBY;
    
    this->dioIrq = new DioIrqHandler[6];

    this->dioIrq[0] = &SX1276::OnDio0Irq;
    this->dioIrq[1] = &SX1276::OnDio1Irq;
    this->dioIrq[2] = &SX1276::OnDio2Irq;
    this->dioIrq[3] = &SX1276::OnDio3Irq;
    this->dioIrq[4] = &SX1276::OnDio4Irq;
    this->dioIrq[5] = NULL;
    
    this->settings.State = IDLE;
}

SX1276::~SX1276( )
{
    delete this->rxBuffer;
    delete this->dioIrq;
}

void SX1276::RxChainCalibration( void )
{
    uint8_t regPaConfigInitVal;
    uint32_t initialFreq;

    // Save context
    regPaConfigInitVal = this->Read( REG_PACONFIG );
    initialFreq = ( double )( ( ( uint32_t )this->Read( REG_FRFMSB ) << 16 ) |
                              ( ( uint32_t )this->Read( REG_FRFMID ) << 8 ) |
                              ( ( uint32_t )this->Read( REG_FRFLSB ) ) ) * ( double )FREQ_STEP;

    // Cut the PA just in case, RFO output, power = -1 dBm
    this->Write( REG_PACONFIG, 0x00 );

    // Launch Rx chain calibration for LF band
    Write ( REG_IMAGECAL, ( Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_MASK ) | RF_IMAGECAL_IMAGECAL_START );
    while( ( Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_RUNNING ) == RF_IMAGECAL_IMAGECAL_RUNNING )
    {
    }

    // Sets a Frequency in HF band
    settings.Channel=  868000000 ;

    // Launch Rx chain calibration for HF band 
    Write ( REG_IMAGECAL, ( Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_MASK ) | RF_IMAGECAL_IMAGECAL_START );
    while( ( Read( REG_IMAGECAL ) & RF_IMAGECAL_IMAGECAL_RUNNING ) == RF_IMAGECAL_IMAGECAL_RUNNING )
    {
    }

    // Restore context
    this->Write( REG_PACONFIG, regPaConfigInitVal );
    SetChannel( initialFreq );
}

RadioState SX1276::GetStatus( void )
{
    return this->settings.State;
}

void SX1276::SetChannel( uint32_t freq )
{
    this->settings.Channel = freq;
    freq = ( uint32_t )( ( double )freq / ( double )FREQ_STEP );
    Write( REG_FRFMSB, ( uint8_t )( ( freq >> 16 ) & 0xFF ) );
    Write( REG_FRFMID, ( uint8_t )( ( freq >> 8 ) & 0xFF ) );
    Write( REG_FRFLSB, ( uint8_t )( freq & 0xFF ) );
}

bool SX1276::IsChannelFree( ModemType modem, uint32_t freq, int8_t rssiThresh )
{
    int16_t rssi = 0;
    
    SetModem( modem );

    SetChannel( freq );
    
    SetOpMode( RF_OPMODE_RECEIVER );

    wait_ms( 1 );
    
    rssi = GetRssi( modem );
    
    Sleep( );
    
    if( rssi > ( int16_t )rssiThresh )
    {
        return false;
    }
    return true;
}

uint32_t SX1276::Random( void )
{
    uint8_t i;
    uint32_t rnd = 0;

    /*
     * Radio setup for random number generation 
     */
    // Set LoRa modem ON
    SetModem( MODEM_LORA );

    // Disable LoRa modem interrupts
    Write( 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
    SetOpMode( RF_OPMODE_RECEIVER );

    for( i = 0; i < 32; i++ )
    {
        wait_ms( 1 );
        // Unfiltered RSSI value reading. Only takes the LSB value
        rnd |= ( ( uint32_t )Read( REG_LR_RSSIWIDEBAND ) & 0x01 ) << i;
    }

    Sleep( );

    return rnd;
}

/*!
 * Returns the known FSK bandwidth registers value
 *
 * \param [IN] bandwidth Bandwidth value in Hz
 * \retval regValue Bandwidth register value.
 */
uint8_t SX1276::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 SX1276::SetRxConfig( ModemType 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 )
{
    SetModem( modem );

    switch( modem )
    {
    case MODEM_FSK:
        {
            this->settings.Fsk.Bandwidth = bandwidth;
            this->settings.Fsk.Datarate = datarate;
            this->settings.Fsk.BandwidthAfc = bandwidthAfc;
            this->settings.Fsk.FixLen = fixLen;
            this->settings.Fsk.PayloadLen = payloadLen;
            this->settings.Fsk.CrcOn = crcOn;
            this->settings.Fsk.IqInverted = iqInverted;
            this->settings.Fsk.RxContinuous = rxContinuous;
            this->settings.Fsk.PreambleLen = preambleLen;
            
            datarate = ( uint16_t )( ( double )XTAL_FREQ / ( double )datarate );
            Write( REG_BITRATEMSB, ( uint8_t )( datarate >> 8 ) );
            Write( REG_BITRATELSB, ( uint8_t )( datarate & 0xFF ) );

            Write( REG_RXBW, GetFskBandwidthRegValue( bandwidth ) );
            Write( REG_AFCBW, GetFskBandwidthRegValue( bandwidthAfc ) );

            Write( REG_PREAMBLEMSB, ( uint8_t )( ( preambleLen >> 8 ) & 0xFF ) );
            Write( REG_PREAMBLELSB, ( uint8_t )( preambleLen & 0xFF ) );

            Write( REG_PACKETCONFIG1,
                         ( Read( REG_PACKETCONFIG1 ) & 
                           RF_PACKETCONFIG1_CRC_MASK &
                           RF_PACKETCONFIG1_PACKETFORMAT_MASK ) |
                           ( ( fixLen == 1 ) ? RF_PACKETCONFIG1_PACKETFORMAT_FIXED : RF_PACKETCONFIG1_PACKETFORMAT_VARIABLE ) |
                           ( crcOn << 4 ) );
            if( fixLen == 1 )
            {
                Write( REG_PAYLOADLENGTH, payloadLen );
            }
        }
        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;
            this->settings.LoRa.Bandwidth = bandwidth;
            this->settings.LoRa.Datarate = datarate;
            this->settings.LoRa.Coderate = coderate;
            this->settings.LoRa.FixLen = fixLen;
            this->settings.LoRa.PayloadLen = payloadLen;
            this->settings.LoRa.CrcOn = crcOn;
            this->settings.LoRa.FreqHopOn = freqHopOn;
            this->settings.LoRa.HopPeriod = hopPeriod;
            this->settings.LoRa.IqInverted = iqInverted;
            this->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 ) ) )
            {
                this->settings.LoRa.LowDatarateOptimize = 0x01;
            }
            else
            {
                this->settings.LoRa.LowDatarateOptimize = 0x00;
            }

            Write( REG_LR_MODEMCONFIG1, 
                         ( Read( REG_LR_MODEMCONFIG1 ) &
                           RFLR_MODEMCONFIG1_BW_MASK &
                           RFLR_MODEMCONFIG1_CODINGRATE_MASK &
                           RFLR_MODEMCONFIG1_IMPLICITHEADER_MASK ) |
                           ( bandwidth << 4 ) | ( coderate << 1 ) | 
                           fixLen );
                        
            Write( REG_LR_MODEMCONFIG2,
                         ( Read( 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 ) );

            Write( REG_LR_MODEMCONFIG3, 
                         ( Read( REG_LR_MODEMCONFIG3 ) &
                           RFLR_MODEMCONFIG3_LOWDATARATEOPTIMIZE_MASK ) |
                           ( this->settings.LoRa.LowDatarateOptimize << 3 ) );

            Write( REG_LR_SYMBTIMEOUTLSB, ( uint8_t )( symbTimeout & 0xFF ) );
            
            Write( REG_LR_PREAMBLEMSB, ( uint8_t )( ( preambleLen >> 8 ) & 0xFF ) );
            Write( REG_LR_PREAMBLELSB, ( uint8_t )( preambleLen & 0xFF ) );

            if( fixLen == 1 )
            {
                Write( REG_LR_PAYLOADLENGTH, payloadLen );
            }

            if( this->settings.LoRa.FreqHopOn == true )
            {
                Write( REG_LR_PLLHOP, ( Read( REG_LR_PLLHOP ) & RFLR_PLLHOP_FASTHOP_MASK ) | RFLR_PLLHOP_FASTHOP_ON );
                Write( REG_LR_HOPPERIOD, this->settings.LoRa.HopPeriod );
            }

            if( datarate == 6 )
            {
                Write( REG_LR_DETECTOPTIMIZE, 
                             ( Read( REG_LR_DETECTOPTIMIZE ) &
                               RFLR_DETECTIONOPTIMIZE_MASK ) |
                               RFLR_DETECTIONOPTIMIZE_SF6 );
                Write( REG_LR_DETECTIONTHRESHOLD, 
                             RFLR_DETECTIONTHRESH_SF6 );
            }
            else
            {
                Write( REG_LR_DETECTOPTIMIZE,
                             ( Read( REG_LR_DETECTOPTIMIZE ) &
                             RFLR_DETECTIONOPTIMIZE_MASK ) |
                             RFLR_DETECTIONOPTIMIZE_SF7_TO_SF12 );
                Write( REG_LR_DETECTIONTHRESHOLD, 
                             RFLR_DETECTIONTHRESH_SF7_TO_SF12 );
            }
        }
        break;
    }
}

void SX1276::SetTxConfig( ModemType 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 )
{
    uint8_t paConfig = 0;
    uint8_t paDac = 0;

    SetModem( modem );
    
    paConfig = Read( REG_PACONFIG );
    paDac = Read( REG_PADAC );

    paConfig = ( paConfig & RF_PACONFIG_PASELECT_MASK ) | GetPaSelect( this->settings.Channel );
    paConfig = ( paConfig & RF_PACONFIG_MAX_POWER_MASK ) | 0x70;

    if( ( paConfig & RF_PACONFIG_PASELECT_PABOOST ) == RF_PACONFIG_PASELECT_PABOOST )
    {
        if( power > 17 )
        {
            paDac = ( paDac & RF_PADAC_20DBM_MASK ) | RF_PADAC_20DBM_ON;
        }
        else
        {
            paDac = ( paDac & RF_PADAC_20DBM_MASK ) | RF_PADAC_20DBM_OFF;
        }
        if( ( paDac & RF_PADAC_20DBM_ON ) == RF_PADAC_20DBM_ON )
        {
            if( power < 5 )
            {
                power = 5;
            }
            if( power > 20 )
            {
                power = 20;
            }
            paConfig = ( paConfig & RF_PACONFIG_OUTPUTPOWER_MASK ) | ( uint8_t )( ( uint16_t )( power - 5 ) & 0x0F );
        }
        else
        {
            if( power < 2 )
            {
                power = 2;
            }
            if( power > 17 )
            {
                power = 17;
            }
            paConfig = ( paConfig & RF_PACONFIG_OUTPUTPOWER_MASK ) | ( uint8_t )( ( uint16_t )( power - 2 ) & 0x0F );
        }
    }
    else
    {
        if( power < -1 )
        {
            power = -1;
        }
        if( power > 14 )
        {
            power = 14;
        }
        paConfig = ( paConfig & RF_PACONFIG_OUTPUTPOWER_MASK ) | ( uint8_t )( ( uint16_t )( power + 1 ) & 0x0F );
    }
    Write( REG_PACONFIG, paConfig );
    Write( REG_PADAC, paDac );

    switch( modem )
    {
    case MODEM_FSK:
        {
            this->settings.Fsk.Power = power;
            this->settings.Fsk.Fdev = fdev;
            this->settings.Fsk.Bandwidth = bandwidth;
            this->settings.Fsk.Datarate = datarate;
            this->settings.Fsk.PreambleLen = preambleLen;
            this->settings.Fsk.FixLen = fixLen;
            this->settings.Fsk.CrcOn = crcOn;
            this->settings.Fsk.IqInverted = iqInverted;
            this->settings.Fsk.TxTimeout = timeout;
            
            fdev = ( uint16_t )( ( double )fdev / ( double )FREQ_STEP );
            Write( REG_FDEVMSB, ( uint8_t )( fdev >> 8 ) );
            Write( REG_FDEVLSB, ( uint8_t )( fdev & 0xFF ) );

            datarate = ( uint16_t )( ( double )XTAL_FREQ / ( double )datarate );
            Write( REG_BITRATEMSB, ( uint8_t )( datarate >> 8 ) );
            Write( REG_BITRATELSB, ( uint8_t )( datarate & 0xFF ) );

            Write( REG_PREAMBLEMSB, ( preambleLen >> 8 ) & 0x00FF );
            Write( REG_PREAMBLELSB, preambleLen & 0xFF );

            Write( REG_PACKETCONFIG1,
                         ( Read( REG_PACKETCONFIG1 ) & 
                           RF_PACKETCONFIG1_CRC_MASK &
                           RF_PACKETCONFIG1_PACKETFORMAT_MASK ) |
                           ( ( fixLen == 1 ) ? RF_PACKETCONFIG1_PACKETFORMAT_FIXED : RF_PACKETCONFIG1_PACKETFORMAT_VARIABLE ) |
                           ( crcOn << 4 ) );
        }
        break;
    case MODEM_LORA:
        {
            this->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;
            this->settings.LoRa.Bandwidth = bandwidth;
            this->settings.LoRa.Datarate = datarate;
            this->settings.LoRa.Coderate = coderate;
            this->settings.LoRa.PreambleLen = preambleLen;
            this->settings.LoRa.FixLen = fixLen;
            this->settings.LoRa.CrcOn = crcOn;
            this->settings.LoRa.FreqHopOn = freqHopOn;
            this->settings.LoRa.HopPeriod = hopPeriod;
            this->settings.LoRa.IqInverted = iqInverted;
            this->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 ) ) )
            {
                this->settings.LoRa.LowDatarateOptimize = 0x01;
            }
            else
            {
                this->settings.LoRa.LowDatarateOptimize = 0x00;
            }
            
            if( this->settings.LoRa.FreqHopOn == true )
            {
                Write( REG_LR_PLLHOP, ( Read( REG_LR_PLLHOP ) & RFLR_PLLHOP_FASTHOP_MASK ) | RFLR_PLLHOP_FASTHOP_ON );
                Write( REG_LR_HOPPERIOD, this->settings.LoRa.HopPeriod );
            }
            
            Write( REG_LR_MODEMCONFIG1, 
                         ( Read( REG_LR_MODEMCONFIG1 ) &
                           RFLR_MODEMCONFIG1_BW_MASK &
                           RFLR_MODEMCONFIG1_CODINGRATE_MASK &
                           RFLR_MODEMCONFIG1_IMPLICITHEADER_MASK ) |
                           ( bandwidth << 4 ) | ( coderate << 1 ) | 
                           fixLen );

            Write( REG_LR_MODEMCONFIG2,
                         ( Read( REG_LR_MODEMCONFIG2 ) &
                           RFLR_MODEMCONFIG2_SF_MASK &
                           RFLR_MODEMCONFIG2_RXPAYLOADCRC_MASK ) |
                           ( datarate << 4 ) | ( crcOn << 2 ) );

            Write( REG_LR_MODEMCONFIG3, 
                         ( Read( REG_LR_MODEMCONFIG3 ) &
                           RFLR_MODEMCONFIG3_LOWDATARATEOPTIMIZE_MASK ) |
                           ( this->settings.LoRa.LowDatarateOptimize << 3 ) );
        
            Write( REG_LR_PREAMBLEMSB, ( preambleLen >> 8 ) & 0x00FF );
            Write( REG_LR_PREAMBLELSB, preambleLen & 0xFF );
            
            if( datarate == 6 )
            {
                Write( REG_LR_DETECTOPTIMIZE, 
                             ( Read( REG_LR_DETECTOPTIMIZE ) &
                               RFLR_DETECTIONOPTIMIZE_MASK ) |
                               RFLR_DETECTIONOPTIMIZE_SF6 );
                Write( REG_LR_DETECTIONTHRESHOLD, 
                             RFLR_DETECTIONTHRESH_SF6 );
            }
            else
            {
                Write( REG_LR_DETECTOPTIMIZE,
                             ( Read( REG_LR_DETECTOPTIMIZE ) &
                             RFLR_DETECTIONOPTIMIZE_MASK ) |
                             RFLR_DETECTIONOPTIMIZE_SF7_TO_SF12 );
                Write( REG_LR_DETECTIONTHRESHOLD, 
                             RFLR_DETECTIONTHRESH_SF7_TO_SF12 );
            }
        }
        break;
    }
}

double SX1276::TimeOnAir( ModemType modem, uint8_t pktLen )
{
    double airTime = 0.0;

    switch( modem )
    {
    case MODEM_FSK:
        {
            airTime = ceil( ( 8 * ( this->settings.Fsk.PreambleLen +
                                     ( ( Read( REG_SYNCCONFIG ) & ~RF_SYNCCONFIG_SYNCSIZE_MASK ) + 1 ) +
                                     ( ( this->settings.Fsk.FixLen == 0x01 ) ? 0.0 : 1.0 ) +
                                     ( ( ( Read( REG_PACKETCONFIG1 ) & ~RF_PACKETCONFIG1_ADDRSFILTERING_MASK ) != 0x00 ) ? 1.0 : 0 ) +
                                     pktLen +
                                     ( ( this->settings.Fsk.CrcOn == 0x01 ) ? 2.0 : 0 ) ) /
                                     this->settings.Fsk.Datarate ) * 1e6 );
        }
        break;
    case MODEM_LORA:
        {
            double bw = 0.0;
            // REMARK: When using LoRa modem only bandwidths 125, 250 and 500 kHz are supported
            switch( this->settings.LoRa.Bandwidth )
            {
            //case 0: // 7.8 kHz
            //    bw = 78e2;
            //    break;
            //case 1: // 10.4 kHz
            //    bw = 104e2;
            //    break;
            //case 2: // 15.6 kHz
            //    bw = 156e2;
            //    break;
            //case 3: // 20.8 kHz
            //    bw = 208e2;
            //    break;
            //case 4: // 31.2 kHz
            //    bw = 312e2;
            //    break;
            //case 5: // 41.4 kHz
            //    bw = 414e2;
            //    break;
            //case 6: // 62.5 kHz
            //    bw = 625e2;
            //    break;
            case 7: // 125 kHz
                bw = 125e3;
                break;
            case 8: // 250 kHz
                bw = 250e3;
                break;
            case 9: // 500 kHz
                bw = 500e3;
                break;
            }

            // Symbol rate : time for one symbol (secs)
            double rs = bw / ( 1 << this->settings.LoRa.Datarate );
            double ts = 1 / rs;
            // time of preamble
            double tPreamble = ( this->settings.LoRa.PreambleLen + 4.25 ) * ts;
            // Symbol length of payload and time
            double tmp = ceil( ( 8 * pktLen - 4 * this->settings.LoRa.Datarate +
                                 28 + 16 * this->settings.LoRa.CrcOn -
                                 ( this->settings.LoRa.FixLen ? 20 : 0 ) ) /
                                 ( double )( 4 * this->settings.LoRa.Datarate -
                                 ( ( this->settings.LoRa.LowDatarateOptimize > 0 ) ? 8 : 0 ) ) ) *
                                 ( this->settings.LoRa.Coderate + 4 );
            double nPayload = 8 + ( ( tmp > 0 ) ? tmp : 0 );
            double tPayload = nPayload * ts;
            // Time on air 
            double tOnAir = tPreamble + tPayload;
            // return us secs
            airTime = floor( tOnAir * 1e6 + 0.999 );
        }
        break;
    }
    return airTime;
}

void SX1276::Send( uint8_t *buffer, uint8_t size )
{
    uint32_t txTimeout = 0;

    this->settings.State = IDLE;

    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        {
            this->settings.FskPacketHandler.NbBytes = 0;
            this->settings.FskPacketHandler.Size = size;

            if( this->settings.Fsk.FixLen == false )
            {
                WriteFifo( ( uint8_t* )&size, 1 );
            }
            else
            {
                Write( REG_PAYLOADLENGTH, size );
            }            
            
            if( ( size > 0 ) && ( size <= 64 ) )
            {
                this->settings.FskPacketHandler.ChunkSize = size;
            }
            else
            {
                this->settings.FskPacketHandler.ChunkSize = 32;
            }

            // Write payload buffer
            WriteFifo( buffer, this->settings.FskPacketHandler.ChunkSize );
            this->settings.FskPacketHandler.NbBytes += this->settings.FskPacketHandler.ChunkSize;
            txTimeout = this->settings.Fsk.TxTimeout;
        }
        break;
    case MODEM_LORA:
        {
            if( this->settings.LoRa.IqInverted == true )
            {
                Write( REG_LR_INVERTIQ, ( ( Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_ON ) );
            }
            else
            {
                Write( REG_LR_INVERTIQ, ( ( Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_OFF ) );
            }      
        
            this->settings.LoRaPacketHandler.Size = size;

            // Initializes the payload size
            Write( REG_LR_PAYLOADLENGTH, size );

            // Full buffer used for Tx            
            Write( REG_LR_FIFOTXBASEADDR, 0 );
            Write( REG_LR_FIFOADDRPTR, 0 );

            // FIFO operations can not take place in Sleep mode
            if( ( Read( REG_OPMODE ) & ~RF_OPMODE_MASK ) == RF_OPMODE_SLEEP )
            {
                Standby( );
                wait_ms( 1 );
            }
            // Write payload buffer
            WriteFifo( buffer, size );
            txTimeout = this->settings.LoRa.TxTimeout;
        }
        break;
    }

    Tx( txTimeout );
}

void SX1276::Sleep( void )
{
    // Initialize driver timeout timers
    txTimeoutTimer.detach(  );
    rxTimeoutTimer.detach( );
    SetOpMode( RF_OPMODE_SLEEP );
}

void SX1276::Standby( void )
{
    txTimeoutTimer.detach(  );
    rxTimeoutTimer.detach( );
    SetOpMode( RF_OPMODE_STANDBY );
}

void SX1276::Rx( uint32_t timeout )
{
    bool rxContinuous = false;

    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        {
            rxContinuous = this->settings.Fsk.RxContinuous;
            
            // DIO0=PayloadReady
            // DIO1=FifoLevel
            // DIO2=SyncAddr
            // DIO3=FifoEmpty
            // DIO4=Preamble
            // DIO5=ModeReady
            Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RF_DIOMAPPING1_DIO0_MASK & RF_DIOMAPPING1_DIO1_MASK &
                                                                            RF_DIOMAPPING1_DIO2_MASK ) |
                                                                            RF_DIOMAPPING1_DIO0_00 |
                                                                            RF_DIOMAPPING1_DIO2_11 );
            
            Write( REG_DIOMAPPING2, ( Read( REG_DIOMAPPING2 ) & RF_DIOMAPPING2_DIO4_MASK &
                                                                            RF_DIOMAPPING2_MAP_MASK ) | 
                                                                            RF_DIOMAPPING2_DIO4_11 |
                                                                            RF_DIOMAPPING2_MAP_PREAMBLEDETECT );
            
            this->settings.FskPacketHandler.FifoThresh = Read( REG_FIFOTHRESH ) & 0x3F;
            
            this->settings.FskPacketHandler.PreambleDetected = false;
            this->settings.FskPacketHandler.SyncWordDetected = false;
            this->settings.FskPacketHandler.NbBytes = 0;
            this->settings.FskPacketHandler.Size = 0;
        }
        break;
    case MODEM_LORA:
        {
            if( this->settings.LoRa.IqInverted == true )
            {
                Write( REG_LR_INVERTIQ, ( ( Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_ON | RFLR_INVERTIQ_TX_OFF ) );
            }
            else
            {
                Write( REG_LR_INVERTIQ, ( ( Read( REG_LR_INVERTIQ ) & RFLR_INVERTIQ_TX_MASK & RFLR_INVERTIQ_RX_MASK ) | RFLR_INVERTIQ_RX_OFF | RFLR_INVERTIQ_TX_OFF ) );
            }         
        
            rxContinuous = this->settings.LoRa.RxContinuous;
            
            if( this->settings.LoRa.FreqHopOn == true )
            {
                Write( 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
                Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK & RFLR_DIOMAPPING1_DIO2_MASK  ) | RFLR_DIOMAPPING1_DIO0_00 | RFLR_DIOMAPPING1_DIO2_00 );
            }
            else
            {
                Write( 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
                Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_00 );
            }
            
            Write( REG_LR_FIFORXBASEADDR, 0 );
            Write( REG_LR_FIFOADDRPTR, 0 );
        }
        break;
    }

    memset( rxBuffer, 0, ( size_t )RX_BUFFER_SIZE );

    this->settings.State = RX;
    if( timeout != 0 )
    {
        rxTimeoutTimer.attach_us( this, &SX1276::OnTimeoutIrq, timeout );
    }

    if( this->settings.Modem == MODEM_FSK )
    {
        SetOpMode( RF_OPMODE_RECEIVER );
        
        if( rxContinuous == false )
        {
            rxTimeoutSyncWord.attach_us( this, &SX1276::OnTimeoutIrq, ( 8.0 * ( this->settings.Fsk.PreambleLen +
                                                         ( ( Read( REG_SYNCCONFIG ) &
                                                            ~RF_SYNCCONFIG_SYNCSIZE_MASK ) +
                                                         1.0 ) + 1.0 ) /
                                                        ( double )this->settings.Fsk.Datarate ) * 1e6 ) ;
        }
    }
    else
    {
        if( rxContinuous == true )
        {
            SetOpMode( RFLR_OPMODE_RECEIVER );
        }
        else
        {
            SetOpMode( RFLR_OPMODE_RECEIVER_SINGLE );
        }
    }
}

void SX1276::Tx( uint32_t timeout )
{ 
    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        {
            // DIO0=PacketSent
            // DIO1=FifoLevel
            // DIO2=FifoFull
            // DIO3=FifoEmpty
            // DIO4=LowBat
            // DIO5=ModeReady
            Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RF_DIOMAPPING1_DIO0_MASK & RF_DIOMAPPING1_DIO1_MASK &
                                                                            RF_DIOMAPPING1_DIO2_MASK ) );

            Write( REG_DIOMAPPING2, ( Read( REG_DIOMAPPING2 ) & RF_DIOMAPPING2_DIO4_MASK &
                                                                            RF_DIOMAPPING2_MAP_MASK ) );
            this->settings.FskPacketHandler.FifoThresh = Read( REG_FIFOTHRESH ) & 0x3F;
        }
        break;
    case MODEM_LORA:
        {
        
            if( this->settings.LoRa.FreqHopOn == true )
            {
                Write( 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
                Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_01 );
                // DIO2=FhssChangeChannel
                Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO2_MASK ) | RFLR_DIOMAPPING1_DIO2_00 );  
            }
            else
            {
                Write( 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
                Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_01 ); 
            }
        }
        break;
    }

    this->settings.State = TX;
    txTimeoutTimer.attach_us( this, &SX1276::OnTimeoutIrq, timeout );
    SetOpMode( RF_OPMODE_TRANSMITTER );
}

void SX1276::StartCad( void )
{
    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        {
           
        }
        break;
    case MODEM_LORA:
        {
            Write( 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
            Write( REG_DIOMAPPING1, ( Read( REG_DIOMAPPING1 ) & RFLR_DIOMAPPING1_DIO0_MASK ) | RFLR_DIOMAPPING1_DIO0_00 );
            
            this->settings.State = CAD;
            SetOpMode( RFLR_OPMODE_CAD );
        }
        break;
    default:
        break;
    }
}

int16_t SX1276::GetRssi( ModemType modem )
{
    int16_t rssi = 0;

    switch( modem )
    {
    case MODEM_FSK:
        rssi = -( Read( REG_RSSIVALUE ) >> 1 );
        break;
    case MODEM_LORA:
        if( this->settings.Channel > RF_MID_BAND_THRESH )
        {
            rssi = RSSI_OFFSET_HF + Read( REG_LR_RSSIVALUE );
        }
        else
        {
            rssi = RSSI_OFFSET_LF + Read( REG_LR_RSSIVALUE );
        }
        break;
    default:
        rssi = -1;
        break;
    }
    return rssi;
}

void SX1276::SetOpMode( uint8_t opMode )
{
    if( opMode != previousOpMode )
    {
        previousOpMode = opMode;
        if( opMode == RF_OPMODE_SLEEP )
        {
            SetAntSwLowPower( true );
        }
        else
        {
            SetAntSwLowPower( false );
            if( opMode == RF_OPMODE_TRANSMITTER )
            {
                 SetAntSw( 1 );
            }
            else
            {
                 SetAntSw( 0 );
            }
        }
        Write( REG_OPMODE, ( Read( REG_OPMODE ) & RF_OPMODE_MASK ) | opMode );
    }
}

void SX1276::SetModem( ModemType modem )
{
    if( this->settings.Modem != modem )
    {
        this->settings.Modem = modem;
        switch( this->settings.Modem )
        {
        default:
        case MODEM_FSK:
            SetOpMode( RF_OPMODE_SLEEP );
            Write( REG_OPMODE, ( Read( REG_OPMODE ) & RFLR_OPMODE_LONGRANGEMODE_MASK ) | RFLR_OPMODE_LONGRANGEMODE_OFF );
        
            Write( REG_DIOMAPPING1, 0x00 );
            Write( REG_DIOMAPPING2, 0x30 ); // DIO5=ModeReady
            break;
        case MODEM_LORA:
            SetOpMode( RF_OPMODE_SLEEP );
            Write( REG_OPMODE, ( Read( REG_OPMODE ) & RFLR_OPMODE_LONGRANGEMODE_MASK ) | RFLR_OPMODE_LONGRANGEMODE_ON );
            Write( 0x30, 0x00 ); //  IF = 0
            Write( REG_LR_DETECTOPTIMIZE, ( Read( REG_LR_DETECTOPTIMIZE ) & 0x7F ) ); // Manual IF
            Write( REG_DIOMAPPING1, 0x00 );
            Write( REG_DIOMAPPING2, 0x00 );
            break;
        }
    }
}

void SX1276::SetMaxPayloadLength( ModemType modem, uint8_t max )
{
    this->SetModem( modem );

    switch( modem )
    {
    case MODEM_FSK:
        if( this->settings.Fsk.FixLen == false )
        {
            this->Write( REG_PAYLOADLENGTH, max );
        }
        break;
    case MODEM_LORA:
        this->Write( REG_LR_PAYLOADMAXLENGTH, max );
        break;
    }
}

void SX1276::OnTimeoutIrq( void )
{
    switch( this->settings.State )
    {
    case RX:
        if( this->settings.Modem == MODEM_FSK )
        {
            this->settings.FskPacketHandler.PreambleDetected = false;
            this->settings.FskPacketHandler.SyncWordDetected = false;
            this->settings.FskPacketHandler.NbBytes = 0;
            this->settings.FskPacketHandler.Size = 0;

            // Clear Irqs
            Write( REG_IRQFLAGS1, RF_IRQFLAGS1_RSSI | 
                                        RF_IRQFLAGS1_PREAMBLEDETECT |
                                        RF_IRQFLAGS1_SYNCADDRESSMATCH );
            Write( REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN );

            if( this->settings.Fsk.RxContinuous == true )
            {
                // Continuous mode restart Rx chain
                Write( REG_RXCONFIG, Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
            }
            else
            {
                this->settings.State = IDLE;
                rxTimeoutSyncWord.detach( );
            }
        }
        if( ( rxTimeout != NULL ) )
        {
            rxTimeout( );
        }
        break;
    case TX:
        this->settings.State = IDLE;
        if( ( txTimeout != NULL ) )
        {
            txTimeout( );
        }
        break;
    default:
        break;
    }
}

void SX1276::OnDio0Irq( void )
{
    volatile uint8_t irqFlags = 0;
  
    switch( this->settings.State )
    {                
        case RX:
            //TimerStop( &RxTimeoutTimer );
            // RxDone interrupt
            switch( this->settings.Modem )
            {
            case MODEM_FSK:
                if( this->settings.Fsk.CrcOn == true )
                {
                    irqFlags = Read( REG_IRQFLAGS2 );
                    if( ( irqFlags & RF_IRQFLAGS2_CRCOK ) != RF_IRQFLAGS2_CRCOK )
                    {
                        // Clear Irqs
                        Write( REG_IRQFLAGS1, RF_IRQFLAGS1_RSSI | 
                                                    RF_IRQFLAGS1_PREAMBLEDETECT |
                                                    RF_IRQFLAGS1_SYNCADDRESSMATCH );
                        Write( REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN );
    
                        if( this->settings.Fsk.RxContinuous == false )
                        {
                            this->settings.State = IDLE;
                            rxTimeoutSyncWord.attach_us( this, &SX1276::OnTimeoutIrq, (  8.0 * ( this->settings.Fsk.PreambleLen +
                                                             ( ( Read( REG_SYNCCONFIG ) &
                                                                ~RF_SYNCCONFIG_SYNCSIZE_MASK ) +
                                                             1.0 ) + 1.0 ) /
                                                            ( double )this->settings.Fsk.Datarate ) * 1e6 ) ;
                        }
                        else
                        {
                            // Continuous mode restart Rx chain
                            Write( REG_RXCONFIG, Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
                        }
                        rxTimeoutTimer.detach( );
    
                        if( ( rxError != NULL ) )
                        {
                            rxError( ); 
                        }
                        this->settings.FskPacketHandler.PreambleDetected = false;
                        this->settings.FskPacketHandler.SyncWordDetected = false;
                        this->settings.FskPacketHandler.NbBytes = 0;
                        this->settings.FskPacketHandler.Size = 0;
                        break;
                    }
                }
                
                // Read received packet size
                if( ( this->settings.FskPacketHandler.Size == 0 ) && ( this->settings.FskPacketHandler.NbBytes == 0 ) )
                {
                    if( this->settings.Fsk.FixLen == false )
                    {
                        ReadFifo( ( uint8_t* )&this->settings.FskPacketHandler.Size, 1 );
                    }
                    else
                    {
                        this->settings.FskPacketHandler.Size = Read( REG_PAYLOADLENGTH );
                    }
                    ReadFifo( rxBuffer + this->settings.FskPacketHandler.NbBytes, this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                    this->settings.FskPacketHandler.NbBytes += ( this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                }
                else
                {
                    ReadFifo( rxBuffer + this->settings.FskPacketHandler.NbBytes, this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                    this->settings.FskPacketHandler.NbBytes += ( this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                }

                if( this->settings.Fsk.RxContinuous == false )
                {
                    this->settings.State = IDLE;
                    rxTimeoutSyncWord.attach_us( this, &SX1276::OnTimeoutIrq, ( 8.0 * ( this->settings.Fsk.PreambleLen +
                                                         ( ( Read( REG_SYNCCONFIG ) &
                                                            ~RF_SYNCCONFIG_SYNCSIZE_MASK ) +
                                                         1.0 ) + 1.0 ) /
                                                        ( double )this->settings.Fsk.Datarate ) * 1e6 ) ;
                }
                else
                {
                    // Continuous mode restart Rx chain
                    Write( REG_RXCONFIG, Read( REG_RXCONFIG ) | RF_RXCONFIG_RESTARTRXWITHOUTPLLLOCK );
                }
                rxTimeoutTimer.detach( );

                if( (rxDone != NULL ) )
                {
                    rxDone( rxBuffer, this->settings.FskPacketHandler.Size, this->settings.FskPacketHandler.RssiValue, 0 ); 
                } 
                this->settings.FskPacketHandler.PreambleDetected = false;
                this->settings.FskPacketHandler.SyncWordDetected = false;
                this->settings.FskPacketHandler.NbBytes = 0;
                this->settings.FskPacketHandler.Size = 0;
                break;
            case MODEM_LORA:
                {
                    uint8_t snr = 0;

                    // Clear Irq
                    Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_RXDONE );

                    irqFlags = Read( REG_LR_IRQFLAGS );
                    if( ( irqFlags & RFLR_IRQFLAGS_PAYLOADCRCERROR_MASK ) == RFLR_IRQFLAGS_PAYLOADCRCERROR )
                    {
                        // Clear Irq
                        Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_PAYLOADCRCERROR );

                        if( this->settings.LoRa.RxContinuous == false )
                        {
                            this->settings.State = IDLE;
                        }
                        rxTimeoutTimer.detach( );

                        if( ( rxError != NULL ) )
                        {
                            rxError( ); 
                        }
                        break;
                    }

                    this->settings.LoRaPacketHandler.SnrValue = Read( REG_LR_PKTSNRVALUE );
                    if( this->settings.LoRaPacketHandler.SnrValue & 0x80 ) // The SNR sign bit is 1
                    {
                        // Invert and divide by 4
                        snr = ( ( ~this->settings.LoRaPacketHandler.SnrValue + 1 ) & 0xFF ) >> 2;
                        snr = -snr;
                    }
                    else
                    {
                        // Divide by 4
                        snr = ( this->settings.LoRaPacketHandler.SnrValue & 0xFF ) >> 2;
                    }

                    int16_t rssi = Read( REG_LR_PKTRSSIVALUE );
                    if( this->settings.LoRaPacketHandler.SnrValue < 0 )
                    {
                        if( this->settings.Channel > RF_MID_BAND_THRESH )
                        {
                            this->settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_HF + rssi + ( rssi >> 4 ) +
                                                                          snr;
                        }
                        else
                        {
                            this->settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_LF + rssi + ( rssi >> 4 ) +
                                                                          snr;
                        }
                    }
                    else
                    {    
                        if( this->settings.Channel > RF_MID_BAND_THRESH )
                        {
                            this->settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_HF + rssi + ( rssi >> 4 );
                        }
                        else
                        {
                            this->settings.LoRaPacketHandler.RssiValue = RSSI_OFFSET_LF + rssi + ( rssi >> 4 );
                        }
                    }

                    this->settings.LoRaPacketHandler.Size = Read( REG_LR_RXNBBYTES );
                    ReadFifo( rxBuffer, this->settings.LoRaPacketHandler.Size );
                
                    if( this->settings.LoRa.RxContinuous == false )
                    {
                        this->settings.State = IDLE;
                    }
                    rxTimeoutTimer.detach( );

                    if( ( rxDone != NULL ) )
                    {
                        rxDone( rxBuffer, this->settings.LoRaPacketHandler.Size, this->settings.LoRaPacketHandler.RssiValue, this->settings.LoRaPacketHandler.SnrValue );
                    }
                }
                break;
            default:
                break;
            }
            break;
        case TX:
            txTimeoutTimer.detach(  );
            // TxDone interrupt
            switch( this->settings.Modem )
            {
            case MODEM_LORA:
                // Clear Irq
                Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_TXDONE );
                // Intentional fall through
            case MODEM_FSK:
            default:
                this->settings.State = IDLE;
                if( ( txDone != NULL ) )
                {
                    txDone( ); 
                } 
                break;
            }
            break;
        default:
            break;
    }
}

void SX1276::OnDio1Irq( void )
{
    switch( this->settings.State )
    {                
        case RX:
            switch( this->settings.Modem )
            {
            case MODEM_FSK:
                // FifoLevel interrupt
                // Read received packet size
                if( ( this->settings.FskPacketHandler.Size == 0 ) && ( this->settings.FskPacketHandler.NbBytes == 0 ) )
                {
                    if( this->settings.Fsk.FixLen == false )
                    {
                        ReadFifo( ( uint8_t* )&this->settings.FskPacketHandler.Size, 1 );
                    }
                    else
                    {
                        this->settings.FskPacketHandler.Size = Read( REG_PAYLOADLENGTH );
                    }
                }

                if( ( this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes ) > this->settings.FskPacketHandler.FifoThresh )
                {
                    ReadFifo( ( rxBuffer + this->settings.FskPacketHandler.NbBytes ), this->settings.FskPacketHandler.FifoThresh );
                    this->settings.FskPacketHandler.NbBytes += this->settings.FskPacketHandler.FifoThresh;
                }
                else
                {
                    ReadFifo( ( rxBuffer + this->settings.FskPacketHandler.NbBytes ), this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                    this->settings.FskPacketHandler.NbBytes += ( this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                }
                break;
            case MODEM_LORA:
                // Sync time out
                rxTimeoutTimer.detach( );
                this->settings.State = IDLE;
                if( ( rxTimeout != NULL ) )
                {
                    rxTimeout( );
                }
                break;
            default:
                break;
            }
            break;
        case TX:
            switch( this->settings.Modem )
            {
            case MODEM_FSK:
                // FifoLevel interrupt
                if( ( this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes ) > this->settings.FskPacketHandler.ChunkSize )
                {
                    WriteFifo( ( rxBuffer + this->settings.FskPacketHandler.NbBytes ), this->settings.FskPacketHandler.ChunkSize );
                    this->settings.FskPacketHandler.NbBytes += this->settings.FskPacketHandler.ChunkSize;
                }
                else 
                {
                    // Write the last chunk of data
                    WriteFifo( rxBuffer + this->settings.FskPacketHandler.NbBytes, this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes );
                    this->settings.FskPacketHandler.NbBytes += this->settings.FskPacketHandler.Size - this->settings.FskPacketHandler.NbBytes;
                }
                break;
            case MODEM_LORA:
                break;
            default:
                break;
            }
            break;      
        default:
            break;
    }
}

void SX1276::OnDio2Irq( void )
{
    switch( this->settings.State )
    {                
        case RX:
            switch( this->settings.Modem )
            {
            case MODEM_FSK:
                if( ( this->settings.FskPacketHandler.PreambleDetected == true ) && ( this->settings.FskPacketHandler.SyncWordDetected == false ) )
                {
                    rxTimeoutSyncWord.detach( );
                    
                    this->settings.FskPacketHandler.SyncWordDetected = true;
                
                    this->settings.FskPacketHandler.RssiValue = -( Read( REG_RSSIVALUE ) >> 1 );

                    this->settings.FskPacketHandler.AfcValue = ( int32_t )( double )( ( ( uint16_t )Read( REG_AFCMSB ) << 8 ) |
                                                                           ( uint16_t )Read( REG_AFCLSB ) ) *
                                                                           ( double )FREQ_STEP;
                    this->settings.FskPacketHandler.RxGain = ( Read( REG_LNA ) >> 5 ) & 0x07;
                }
                break;
            case MODEM_LORA:
                if( this->settings.LoRa.FreqHopOn == true )
                {
                    // Clear Irq
                    Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL );
                    
                    if( ( fhssChangeChannel != NULL ) )
                    {
                        fhssChangeChannel( ( Read( REG_LR_HOPCHANNEL ) & RFLR_HOPCHANNEL_CHANNEL_MASK ) );
                    }
                }    
                break;
            default:
                break;
            }
            break;
        case TX:
            switch( this->settings.Modem )
            {
            case MODEM_FSK:
                break;
            case MODEM_LORA:
                if( this->settings.LoRa.FreqHopOn == true )
                {
                    // Clear Irq
                    Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_FHSSCHANGEDCHANNEL );
                    
                    if( ( fhssChangeChannel != NULL ) )
                    {
                        fhssChangeChannel( ( Read( REG_LR_HOPCHANNEL ) & RFLR_HOPCHANNEL_CHANNEL_MASK ) );
                    }
                }    
                break;
            default:
                break;
            }
            break;      
        default:
            break;
    }
}

void SX1276::OnDio3Irq( void )
{
    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        break;
    case MODEM_LORA:
        if( ( Read( REG_LR_IRQFLAGS ) & 0x01 ) == 0x01 )
        {
            // Clear Irq
            Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_CADDETECTED_MASK | RFLR_IRQFLAGS_CADDONE);
            if( ( cadDone != NULL ) )
            {
                cadDone( true );
            }
        }
        else
        {        
            // Clear Irq
            Write( REG_LR_IRQFLAGS, RFLR_IRQFLAGS_CADDONE );
            if( ( cadDone != NULL ) )
            {
                cadDone( false );
            }
        }
        break;
    default:
        break;
    }
}

void SX1276::OnDio4Irq( void )
{
    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        {
            if( this->settings.FskPacketHandler.PreambleDetected == false )
            {
                this->settings.FskPacketHandler.PreambleDetected = true;
            }    
        }
        break;
    case MODEM_LORA:
        break;
    default:
        break;
    }
}

void SX1276::OnDio5Irq( void )
{
    switch( this->settings.Modem )
    {
    case MODEM_FSK:
        break;
    case MODEM_LORA:
        break;
    default:
        break;
    }
}