File content as of revision 16:ef85c3a61509:

#include "mbed.h"
#include "main.h"
#include "sx1272-hal.h"
#include "debug.h"

#define DEBUG_MESSAGE                         0

/* Set this flag to '1' to use the LoRa modulation or to '0' to use FSK modulation */
#define USE_MODEM_LORA                        1
#define USE_MODEM_FSK                         !USE_MODEM_LORA

#define RF_FREQUENCY                          868000000 // Hz
#define TX_OUTPUT_POWER                       14    // 14 dBm
/**** LORA_BANDWIDTH 0:125khz / 1:250khz / 2:500khz ****/
#define LORA_BANDWIDTH                        2 
#define LORA_SPREADING_FACTOR                 7         // [SF7..SF12]
/**** LORA_CODINGRATE 1:4/5  /  2:4/6  / 3:4/7  /  4:4/8 ****/ 
#define LORA_CODINGRATE                       1         // [1: 4/5,
#define LORA_PREAMBLE_LENGTH                  8         // Same for Tx and Rx
#define LORA_SYMBOL_TIMEOUT                   5         // Symbols
#define LORA_FIX_LENGTH_PAYLOAD_ON            false
#define LORA_FHSS_ENABLED                     false  
#define LORA_NB_SYMB_HOP                      4     
#define LORA_IQ_INVERSION_ON                  false
#define LORA_CRC_ENABLED                      true

#define RX_TIMEOUT_VALUE                      3500      // in ms
#define BUFFER_SIZE                           32        // Define the payload size here

DigitalOut led( LED1 );

/*
 *  Global variables declarations
 */
typedef enum
{
    LOWPOWER = 0,
    IDLE,
    RX,
    RX_TIMEOUT,
    RX_ERROR,
    TX,
    TX_TIMEOUT,
    CAD,
    CAD_DONE
}AppStates_t;

volatile AppStates_t State = LOWPOWER;

/*!
 * Radio events function pointer
 */
static RadioEvents_t RadioEvents;

/*
 *  Global variables declarations
 */
SX1272MB2xAS Radio( NULL );

const uint8_t PingMsg[] = "PING";
const uint8_t PongMsg[] = "PONG";

uint16_t BufferSize = BUFFER_SIZE;
uint8_t Buffer[BUFFER_SIZE];

int16_t RssiValue = 0.0;
int8_t SnrValue = 0.0;

int main( void ) 
{
    uint8_t i;
    bool isMaster = true;

    debug( "\n\r > SX1272 Ping Pong Demo Application " );

    // Initialize Radio driver
    RadioEvents.TxDone = OnTxDone;
    RadioEvents.RxDone = OnRxDone;
    RadioEvents.RxError = OnRxError;
    RadioEvents.TxTimeout = OnTxTimeout;
    RadioEvents.RxTimeout = OnRxTimeout;
    Radio.Init( &RadioEvents );

    // verify the connection with the board
    while( Radio.Read( REG_VERSION ) == 0x00  )
    {
        debug( "Radio could not be detected!\n\r", NULL );
        wait( 1 );
    }

    Radio.SetChannel( RF_FREQUENCY ); 
    Radio.SetTxConfig( MODEM_LORA, TX_OUTPUT_POWER, 0, LORA_BANDWIDTH,
                         LORA_SPREADING_FACTOR, LORA_CODINGRATE,
                         LORA_PREAMBLE_LENGTH, LORA_FIX_LENGTH_PAYLOAD_ON,
                         LORA_CRC_ENABLED, LORA_FHSS_ENABLED, LORA_NB_SYMB_HOP,
                         LORA_IQ_INVERSION_ON, 2000 );
    Radio.SetRxConfig( MODEM_LORA, LORA_BANDWIDTH, LORA_SPREADING_FACTOR,
                         LORA_CODINGRATE, 0, LORA_PREAMBLE_LENGTH,
                         LORA_SYMBOL_TIMEOUT, LORA_FIX_LENGTH_PAYLOAD_ON, 0,
                         LORA_CRC_ENABLED, LORA_FHSS_ENABLED, LORA_NB_SYMB_HOP,
                         LORA_IQ_INVERSION_ON, true );


    debug( "Starting Ping-Pong loop\r\n\n" );
    debug( "Start as Master : Envoi de Ping \r\n" );
    led = 0;

    Radio.Rx( RX_TIMEOUT_VALUE );

    while( 1 )
    {
        switch( State )
        {
        case RX:
            debug( "\r\n" );
            if( isMaster == true )
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PongMsg, 4 ) == 0 )
                    {
                        led = !led;
                        debug( "Master : Pong recu !!!\r\n" );
                        // Send the next PING frame
                        strcpy( ( char* )Buffer, ( char* )PingMsg );
                        // We fill the buffer with numbers for the payload
                        for( i = 4; i < BufferSize; i++ )
                        {
                            Buffer[i] = i - 4;
                        }
                        wait_ms( 1000 );
                        debug( "Master : Envoi de Ping\r\n" );
                        Radio.Send( Buffer, BufferSize );
                    }
                    else if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    { // A master already exists then become a slave
                        debug( "Master : Ping recu !!!\r\n" );
                        debug( "A master already exists then become a slave\r\n" );
                        led = !led;
                        isMaster = false;
                        // Send the next PONG frame
                        strcpy( ( char* )Buffer, ( char* )PongMsg );
                        // We fill the buffer with numbers for the payload
                        for( i = 4; i < BufferSize; i++ )
                        {
                            Buffer[i] = i - 4;
                        }
                        wait_ms( 1000 );
                         debug( "Master : Envoi de Pong\r\n" );
                        Radio.Send( Buffer, BufferSize );
                    }
                    else // valid reception but neither a PING or a PONG message
                    {    // Set device as master ans start again
                        isMaster = true;
                        debug( "Master : Reception valide, Ni Ping, Ni Pong\r\n" );
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }
                }
            }
            else
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    {
                        led = !led;
                        debug( "Slave : Ping recu\r\n" );
                        // Send the reply to the PING string
                        strcpy( ( char* )Buffer, ( char* )PongMsg );
                        // We fill the buffer with numbers for the payload
                        for( i = 4; i < BufferSize; i++ )
                        {
                            Buffer[i] = i - 4;
                        }
                        wait_ms( 1000 );
                        debug( "Slave : Envoi de Pong\r\n" );
                        Radio.Send( Buffer, BufferSize );
                    }
                    else // valid reception but not a PING as expected
                    {    // Set device as master and start again
                        isMaster = true;
                         debug( "Slave : Reception valide, mais pas un Ping, on repasse Master\r\n" );
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }
                }
            }
            State = LOWPOWER;
            break;
        case TX:
            led = !led;
            if( isMaster == true )  
            {
                //debug( "Ping...\r\n" );
            }
            else
            {
                //debug( "Pong...\r\n" );
            }
            Radio.Rx( RX_TIMEOUT_VALUE );
            State = LOWPOWER;
            break;
        case RX_TIMEOUT:
            if( isMaster == true )
            {
                // Send the next PING frame
                strcpy( ( char* )Buffer, ( char* )PingMsg );
                for( i = 4; i < BufferSize; i++ )
                {
                    Buffer[i] = i - 4;
                }
                wait_ms( 1000 );
                Radio.Send( Buffer, BufferSize );
            }
            else
            {
                Radio.Rx( RX_TIMEOUT_VALUE );
            }
            State = LOWPOWER;
            break;
        case RX_ERROR:
            // We have received a Packet with a CRC error, send reply as if packet was correct
            if( isMaster == true )
            {
                // Send the next PING frame
                strcpy( ( char* )Buffer, ( char* )PingMsg );
                for( i = 4; i < BufferSize; i++ )
                {
                    Buffer[i] = i - 4;
                }
                wait_ms( 1000 );
                Radio.Send( Buffer, BufferSize );
            }
            else
            {
                // Send the next PONG frame
                strcpy( ( char* )Buffer, ( char* )PongMsg );
                for( i = 4; i < BufferSize; i++ )
                {
                    Buffer[i] = i - 4;
                }
                wait_ms( 1000 );
                Radio.Send( Buffer, BufferSize );
            }
            State = LOWPOWER;
            break;
        case TX_TIMEOUT:
            Radio.Rx( RX_TIMEOUT_VALUE );
            State = LOWPOWER;
            break;
        case LOWPOWER:
            break;
        default:
            State = LOWPOWER;
            break;
        }
    }
}

void OnTxDone( void )
{
    Radio.Sleep( );
    State = TX;
    debug_if( DEBUG_MESSAGE, "> OnTxDone\n\r" );
}

void OnRxDone( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr )
{
    Radio.Sleep( );
    BufferSize = size;
    memcpy( Buffer, payload, BufferSize );
    RssiValue = rssi;
    SnrValue = snr;
    State = RX;
    debug_if( DEBUG_MESSAGE, "> OnRxDone : RSSI %d dBm : SNR %d dB \n\r",RssiValue, SnrValue );
}

void OnTxTimeout( void )
{
    Radio.Sleep( );
    State = TX_TIMEOUT;
    debug_if( DEBUG_MESSAGE, "> OnTxTimeout\n\r" );
}

void OnRxTimeout( void )
{
    Radio.Sleep( );
    Buffer[BufferSize] = 0;
    State = RX_TIMEOUT;
    debug_if( DEBUG_MESSAGE, "> OnRxTimeout\n\r" );
}

void OnRxError( void )
{
    Radio.Sleep( );
    State = RX_ERROR;
    debug_if( DEBUG_MESSAGE, "> OnRxError\n\r" );
}