LoRa Confusion

test.c

/*
  This program attempts to change the operation mode of a SX1276.
  
  SPI communication is verified as working, as the program is able to select and verify sleep mode.
  
  The SX1276 refuses to enter RXCONTINUOS mode and instead reverts back to STDBY·
  
  Compile:
    gcc test.c -lwiringPi -o test
  
  Run
    ./test

  Output from program:
    Setting stdby mode...
    Got mode: STDBY

    Setting sleep mode...
    Got mode: SLEEP

    Setting receive mode...
    Got mode: STDBY  
*/

#include <stdio.h>
#include <stdint.h>

#include <wiringPiSPI.h>

#define CHANNEL 0
#define SPEED 500000

#define LORA_SPI_WRITE                   0x80
#define LORA_REG_MODE                    0x01
#define LORA_MODE_FLAG_LONG_RANGE        0x80
#define LORA_MODE_FLAG_ACCESS_SHARED_REG 0x40
#define LORA_MODE_SLEEP                  0x00
#define LORA_MODE_STDBY                  0x01
#define LORA_MODE_FSTX                   0x02
#define LORA_MODE_TX                     0x03
#define LORA_MODE_FSRX                   0x04
#define LORA_MODE_RXCONTINUOUS           0x05
#define LORA_MODE_RXSINGLE               0x06
#define LORA_MODE_CAD                    0x07

uint8_t spiRead(uint8_t reg)
{
  uint8_t block[2];

  block[0] = reg & ~LORA_SPI_WRITE;
  block[1] = 0;

  wiringPiSPIDataRW(CHANNEL, block, 2);

  return block[1];
}

uint8_t spiWrite(uint8_t reg, uint8_t val)
{
  uint8_t block[2];

  block[0] = reg | LORA_SPI_WRITE;
  block[1] = val;

  wiringPiSPIDataRW(CHANNEL, block, 2);

  return block[0];
}

uint8_t getMode(void)
{
  return spiRead(LORA_REG_MODE) & ~LORA_MODE_FLAG_LONG_RANGE;
}

void setMode(uint8_t mode)
{
  spiWrite(LORA_REG_MODE, mode | LORA_MODE_FLAG_LONG_RANGE);
}

const char * modeToString(uint8_t mode)
{
  switch (mode) {
    case LORA_MODE_SLEEP:        return "SLEEP";
    case LORA_MODE_STDBY:        return "STDBY";
    case LORA_MODE_FSTX:         return "FSTX";
    case LORA_MODE_TX:           return "TX";
    case LORA_MODE_FSRX:         return "FSRX";
    case LORA_MODE_RXCONTINUOUS: return "RXCONTINUOUS";
    case LORA_MODE_RXSINGLE:     return "RXSINGLE";
    case LORA_MODE_CAD:          return "CAD";
  }

  return "UNKNOWN";
}

int main(int argc, char *argv[])
{
  if (-1 == wiringPiSPISetup(CHANNEL, SPEED)) {
    puts("Failed to setup SPI channel");
    return 1;
  }

  puts("Setting stdby mode...");
  setMode(LORA_MODE_STDBY);
  printf("Got mode: %s\n\n", modeToString(getMode()));

  puts("Setting sleep mode...");
  setMode(LORA_MODE_SLEEP);
  printf("Got mode: %s\n\n", modeToString(getMode()));

  puts("Setting receive mode...");
  setMode(LORA_MODE_RXCONTINUOUS);
  printf("Got mode: %s\n\n", modeToString(getMode()));

  return 0;
}