Lilygo T-Beam Lora Receiver

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

#define SCK     5    // GPIO5  -- SX1278's SCK
#define MISO    19   // GPIO19 -- SX1278's MISO
#define MOSI    27   // GPIO27 -- SX1278's MOSI
#define SS      18   // GPIO18 -- SX1278's CS
#define RST     14   // GPIO14 -- SX1278's RESET
#define DI0     26   // GPIO26 -- SX1278's IRQ(Interrupt Request)

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

void setup() {
  Serial.begin(115200);
  while (!Serial);

  Serial.println("LoRa Sender");
  SPI.begin(SCK,MISO,MOSI,SS);
  LoRa.setPins(SS,RST,DI0);

  if (!LoRa.begin(434.75E6)) {
    Serial.println("Starting LoRa failed!");
    while (1);
  }

  // Uncomment the next line to disable the default AGC and set LNA gain, values between 1 - 6 are supported
  // LoRa.setGain(6);

  // 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());
}