编写代码实现：其中一个ESP32通过串口每隔3秒发送一个数字至LoRa模块，该数字初始值为1，随后每发送一次该数字增大1，另一个ESP32将LoRa模块接收的到的数字显示在OLED上，分别上传两个ESP32的代码。（LoRa模块出厂默认是透传模式，波特率是9600，无需进行AT配置即可直接进行通信）

ESP32发送端代码：

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

int counter = 1;
unsigned long previousMillis = 0;
const long interval = 3000;  // 每隔3秒发送一次数据

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

  SPI.begin(SCK, MISO, MOSI, SS);
  LoRa.setPins(SS, RST, DI0);

  if (!LoRa.begin(433E6)) {
    Serial.println("LoRa init failed. Check your connections.");
    while (true);
  }
}

void loop() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    LoRa.beginPacket();
    LoRa.print(counter);
    LoRa.endPacket();

    Serial.print("Sent: ");
    Serial.println(counter);

    counter++;
  }
}

ESP32接收端代码：

#include <Wire.h>
#include <LoRa.h>
#include <Adafruit_SSD1306.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)

#define OLED_SDA 21
#define OLED_SCL 22
#define OLED_RST 16

Adafruit_SSD1306 display(128, 64, &Wire, OLED_RST);

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

  SPI.begin(SCK, MISO, MOSI, SS);
  LoRa.setPins(SS, RST, DI0);

  if (!LoRa.begin(433E6)) {
    Serial.println("LoRa init failed. Check your connections.");
    while (true);
  }

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.display();
}

void loop() {
  int packetSize = LoRa.parsePacket();

  if (packetSize) {
    String received = "";

    while (LoRa.available()) {
      received += (char)LoRa.read();
    }

    Serial.print("Received: ");
    Serial.println(received);

    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print("Received:");
    display.setCursor(0, 20);
    display.print(received);
    display.display();
  }
}