Study the different way to know there is an ongoing communication

[tperale]

So far two methods are documented to know if there is an ongoing communication.

• Using MODEMSTAT

uint8_t status;
spi_read_register(__sx1272_dev.spi, REG_LR_MODEMSTAT, &status, 1);
if (status & (0x04 | 0x01)) {
  sx1272_rx_internal_set(&__sx1272_dev, sx1272_rx_receiving);
}

• Using interrupt on DIO3

if (sx1272_read_register(SX1272_DEV.spi, REG_LR_IRQFLAGS) & RFLR_IRQFLAGS_VALIDHEADER) {
  SX1272_DEV.receiv_timestamp = RTIMER_NOW(); // - US_TO_RTIMERTICKS(439)
  sx1272_write_register(SX1272_DEV.spi, REG_LR_IRQFLAGS, RFLR_IRQFLAGS_VALIDHEADER);
  sx1272_rx_internal_set(&SX1272_DEV, sx1272_rx_receiving);
  LOG_DBG("Receiving packet\n");
}

I only managed to make the second one work. I should try to implement the first one and study which one detect an incoming packet faster to reduce the time the radio must spend listening for incoming messages.