/*
  RadioLib SX127x Blocking Channel Activity Detection Example

  This example scans the current LoRa channel and detects
  valid LoRa preambles. Preamble is the first part of
  LoRa transmission, so this can be used to check
  if the LoRa channel is free, or if you should start
  receiving a message.

  Other modules from SX127x/RFM9x family can also be used.

  Using blocking CAD is not recommended, as it will lead
  to significant amount of timeouts, inefficient use of processor
  time and can some miss packets!
  Instead, interrupt CAD is recommended.

  For default module settings, see the wiki page
  https://github.com/jgromes/RadioLib/wiki/Default-configuration#sx127xrfm9x---lora-modem

  For full API reference, see the GitHub Pages
  https://jgromes.github.io/RadioLib/
*/

// include the library
#include <RadioLib.h>

// SX1278 has the following connections:
// NSS pin:   10
// DIO0 pin:  2
// RESET pin: 9
// DIO1 pin:  3
SX1278 radio = new Module(10, 2, 9, 3);

// or detect the pinout automatically using RadioBoards
// https://github.com/radiolib-org/RadioBoards
/*
#define RADIO_BOARD_AUTO
#include <RadioBoards.h>
Radio radio = new RadioModule();
*/

void setup() {
  Serial.begin(9600);

  // initialize SX1278 at 434 MHz
  Serial.print(F("[SX1278] Initializing ... "));
  ConfigLoRa_t config;
  config.frequency = 434;
  int state = radio.begin(config);
  if (state == RADIOLIB_ERR_NONE) {
    Serial.println(F("success!"));
  } else {
    Serial.print(F("failed, code "));
    Serial.println(state);
    while (true) { delay(10); }
  }
}

void loop() {
  Serial.print(F("[SX1278] Scanning channel for LoRa preamble ... "));

  // start scanning current channel
  int state = radio.scanChannel();

  if (state == RADIOLIB_PREAMBLE_DETECTED) {
    // LoRa preamble was detected
    Serial.println(F("detected preamble!"));

  } else if (state == RADIOLIB_CHANNEL_FREE) {
    // no preamble was detected, channel is free
    Serial.println(F("channel is free!"));

  }

  // wait 100 ms before new scan
  delay(100);
}
