//modified lora library by Sandeep Mistry for TTGO ESP32 Lora
// lora receiverCallBack

#include <SPI.h>
#include <LoRa.h>

#ifdef ARDUINO_SAMD_MKRWAN1300
#error "This example is not compatible with the Arduino MKR WAN 1300 board!"
#endif

// GPIO5  -- SX1278's SCK
// GPIO19 -- SX1278's MISO
// GPIO27 -- SX1278's MOSI
// GPIO18 -- SX1278's CS
// GPIO14 -- SX1278's RESET
// GPIO26 -- SX1278's IRQ(Interrupt Request)
 
#define SS      18
#define RST     14
#define DI0     26
#define BAND    433E6

void setup() {
  Serial.begin(115200);
  while (!Serial);
  SPI.begin(5,19,27,18);
  LoRa.setPins(SS,RST,DI0);
  
  Serial.println("LoRa Receiver Callback");

  if (!LoRa.begin(BAND)) {
    Serial.println("Starting LoRa failed!");
    while (1);
  }

  // register the receive callback
  LoRa.onReceive(onReceive);

  // put the radio into receive mode
  LoRa.receive();
}

void loop() {
  // do nothing
}

void onReceive(int packetSize) {
  // received a packet
  Serial.print("Received packet '");

  // read packet
  for (int i = 0; i < packetSize; i++) {
    Serial.print((char)LoRa.read());
  }

  // print RSSI of packet
  Serial.print("' with RSSI ");
  Serial.println(LoRa.packetRssi());
}