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2 years, 1 month ago.

SX1272 Ping Pong example not working.

I have 2 nRF52 dev kits and 2 SX1272MB2DAS Shields. I compiled the PingPong example (https://developer.mbed.org/teams/Semtech/code/SX1272PingPong/) and flashed it to both dev kits. The startup sequence appears to work. I see the output from both devices on their COM ports (using RealTerm), so the code is at least getting to main loop.

However, none of the events from the radio are firing. There's no output on the COM port about any of the events firing (like "OnRxTimeout"). In addition, none of the DIO0 -DIO3 lines are wiggling like they actually have an interrupt.

Here's the code.

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

/* Set this flag to '1' to display debug messages on the console */
#define DEBUG_MESSAGE   1

/* 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                                 0        // 14 dBm

#if USE_MODEM_LORA == 1

    #define LORA_BANDWIDTH                              2         // [0: 125 kHz,
                                                                  //  1: 250 kHz,
                                                                  //  2: 500 kHz,
                                                                  //  3: Reserved]
    #define LORA_SPREADING_FACTOR                       7         // [SF7..SF12]
    #define LORA_CODINGRATE                             1         // [1: 4/5,
                                                                  //  2: 4/6,
                                                                  //  3: 4/7,
                                                                  //  4: 4/8]
    #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
    
#elif USE_MODEM_FSK == 1

    #define FSK_FDEV                                    25000     // Hz
    #define FSK_DATARATE                                19200     // bps
    #define FSK_BANDWIDTH                               50000     // Hz
    #define FSK_AFC_BANDWIDTH                           83333     // Hz
    #define FSK_PREAMBLE_LENGTH                         5         // Same for Tx and Rx
    #define FSK_FIX_LENGTH_PAYLOAD_ON                   false
    #define FSK_CRC_ENABLED                             true
    
#else
    #error "Please define a modem in the compiler options."
#endif

#define RX_TIMEOUT_VALUE                                3500000   // in us
#define BUFFER_SIZE                                     32        // Define the payload size here

#if( defined ( TARGET_KL25Z ) || defined ( TARGET_LPC11U6X ) )
DigitalOut led(LED2);
#else
DigitalOut led(LED1);
#endif

/*
 *  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;
uint32_t count = 0;

int main() 
{
    uint8_t i;
    bool isMaster = true;
    
    debug( "\n\n\r     SX1272 Ping Pong Demo Application \n\n\r" );

    // 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 );
    }
            
    debug_if( ( DEBUG_MESSAGE & ( Radio.DetectBoardType( ) == SX1272MB2XAS ) ) , "\n\r > Board Type: SX1272MB2xAS < \n\r" );
  
    Radio.SetChannel( RF_FREQUENCY ); 

#if USE_MODEM_LORA == 1
    
    debug_if( LORA_FHSS_ENABLED, "\n\n\r             > LORA FHSS Mode < \n\n\r");
    debug_if( !LORA_FHSS_ENABLED, "\n\n\r             > LORA Mode < \n\n\r");

    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, 2000000 );
    
    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 );
                         
#elif USE_MODEM_FSK == 1

    debug("\n\n\r              > FSK Mode < \n\n\r");
    Radio.SetTxConfig( MODEM_FSK, TX_OUTPUT_POWER, FSK_FDEV, 0,
                         FSK_DATARATE, 0,
                         FSK_PREAMBLE_LENGTH, FSK_FIX_LENGTH_PAYLOAD_ON,
                         FSK_CRC_ENABLED, 0, 0, 0, 2000000 );
    
    Radio.SetRxConfig( MODEM_FSK, FSK_BANDWIDTH, FSK_DATARATE,
                         0, FSK_AFC_BANDWIDTH, FSK_PREAMBLE_LENGTH,
                         0, FSK_FIX_LENGTH_PAYLOAD_ON, 0, FSK_CRC_ENABLED,
                         0, 0, false, true );
                         
#else

#error "Please define a modem in the compiler options."

#endif
     
    debug_if( DEBUG_MESSAGE, "Starting Ping-Pong loop\r\n" ); 
        
    led = 0;
        
    Radio.Rx( RX_TIMEOUT_VALUE );
    
    while( 1 )
    {
        switch( State )
        {
        case RX:
            if( isMaster == true )
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PongMsg, 4 ) == 0 )
                    {
                        led = !led;
                        debug( "...Pong\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( 10 ); 
                        Radio.Send( Buffer, BufferSize );
                    }
                    else if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    { // A master already exists then become a slave
                        debug( "...Ping\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( 10 ); 
                        Radio.Send( Buffer, BufferSize );
                    }
                    else // valid reception but neither a PING or a PONG message
                    {    // Set device as master ans start again
                        isMaster = true;
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }    
                }
            }
            else
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    {
                        led = !led;
                        debug( "...Ping\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( 10 );  
                        Radio.Send( Buffer, BufferSize );
                    }
                    else // valid reception but not a PING as expected
                    {    // Set device as master and start again
                        isMaster = true;
                        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( 10 ); 
                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( 10 );  
                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( 10 );  
                Radio.Send( Buffer, BufferSize );
            }
            State = LOWPOWER;
            break;
        case TX_TIMEOUT:
            Radio.Rx( RX_TIMEOUT_VALUE );
            State = LOWPOWER;
            break;
        case LOWPOWER:
            count++;
            if (count % 1000000 == 0)
                debug("still waiting... \n\r");
            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\n\r" );
}

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" );
}


Comment on this question

1 Answer

1 year, 11 months ago.

Did you install the drivers, mbed libraries properly? Also where are you trying to observe the output?


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