File content as of revision 3:5e25ec621190:

#include "radio.h"
#include "mbed.h"
#include "platform/CircularBuffer.h"
#include "MbedJSONValue/MbedJSONValue.h"

// Semtech radio definitions for SX127x, SX126x and SX128x

#if defined(SX127x_H)
    #define BW_KHZ              500
    #define SPREADING_FACTOR    11
    #define CF_HZ               912000000
    #define TX_DBM              20
#elif defined(SX126x_H)
    #define BW_KHZ              500
    #define SPREADING_FACTOR    10
    #define CF_HZ               915000000
    #define TX_DBM              (Radio::chipType == CHIP_TYPE_SX1262 ? 20 : 14) 
#elif defined(SX128x_H)
    #define BW_KHZ              200
    #define SPREADING_FACTOR    7
    #define CF_HZ               2487000000
    #define TX_DBM              6
#endif

// The buffer size should match the tx_buf length in sx12xx.h
#define BUF_SIZE    256

/******************** Setup radio transmitter ****************************/

volatile bool txDone;
CircularBuffer<uint8_t, BUF_SIZE> msg;

void txDoneCB()
{
    txDone = true;
}

void rxDoneCB(uint8_t size, float rssi, float snr)
{
}

    // Define radio events for transmitter

const RadioEvents_t rev = {
    /* Dio0_top_half */     NULL,
    /* TxDone_topHalf */    NULL,
    /* TxDone_botHalf */    txDoneCB,
    /* TxTimeout  */        NULL,
    /* RxDone  */           rxDoneCB,
    /* RxTimeout  */        NULL,
    /* RxError  */          NULL,
    /* FhssChangeChannel  */NULL,
    /* CadDone  */          NULL
};

void print_radio_tx_buffer(uint8_t len)
{
    printf("Tx Buffer = ");
    for(int i=0; i<len; i++)
    {
        printf("%d ", Radio::radio.tx_buf[i]);
    }
    printf("\r\n\n");
}

void msg_append_bytes(uint8_t data[], uint8_t len)
{
    for(int i=0; i < len; i++)
    {
        if(!msg.full())
        {
            msg.push(data[i]);
        }
        else{
            // If buffer is full, contents will be over-written
            // TODO: Handle this error case
            printf("buffer is full\n");
        }
    }
}

void msg_append_string(string str, uint8_t len)
{
    msg_append_bytes(reinterpret_cast<uint8_t*>(&str[0]), len);
}    

void msg_send()
{
    uint8_t len = 0;
    while(!msg.empty())
    {
        // Pop data from the circular buffer to Radio tx_buf
        msg.pop(Radio::radio.tx_buf[len]);
        
        // Track the size of the tx_buf
        len++;
    }
    print_radio_tx_buffer(len);
    txDone = false;
    Radio::Send(len, 0, 0, 0);   // begin transmission of payload 

    while (!txDone)
    {
        Radio::service();
    }
        
    printf("Tx Done.\r\n");
}

void radio_init()
{
    // Start radio transmitter after POR or reset

    Radio::Init(&rev);

    //Set radio properties for transmitter

    Radio::Standby();
    Radio::LoRaModemConfig(BW_KHZ, SPREADING_FACTOR, 1);
    Radio::SetChannel(CF_HZ);

    // Set transmitter output power

    Radio::set_tx_dbm(TX_DBM);

    // Setup transmit packet payload  -> preambleLen, fixLen, crcOn, invIQ
               
    Radio::LoRaPacketConfig(8, false, true, false);
}

int main()
{        
    printf("\r\nreset-tx \n");
    
    radio_init();
    
    uint8_t seq = 0;  //  Set initial transmit sequence to 0

    for (;;) {
        // Create an array to hold byte data
        uint8_t data[] = {seq};
        
        // Append the byte array to the message
        msg_append_bytes(data, sizeof(data)/sizeof(data[0]));
        
        // Append a new value to the message
        data[0] = seq+1;
        msg_append_bytes(data, sizeof(data)/sizeof(data[0]));
        
        // Append a string to the message
        string myString = "Hello World!";
        msg_append_string(myString, myString.length());
        msg_send();

        // Transmit payload every 500mS
        wait(0.5);  // throttle sending rate 
        seq+=2;  // change payload (increment sequence number)
        }
}