Beacon code

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

// Define the UUID for the beacon
#define BEACON_UUID "12345678-1234-5678-1234-56789abcdef0"

void setup() {
  Serial.begin(115200);
  BLEDevice::init(""); // Initialize BLE with an empty name

  // Create the BLE Server
  BLEServer *pServer = BLEDevice::createServer();

  // Create the BLE Service (we use a custom UUID here)
  BLEService *pService = pServer->createService(BEACON_UUID);

  // Create a BLE Characteristic
  BLECharacteristic *pCharacteristic = pService->createCharacteristic(
                                          BLEUUID("12345678-1234-5678-1234-56789abcdef1"),
                                          BLECharacteristic::PROPERTY_READ
                                        );

  // Set the value of the characteristic (this will be broadcasted)
  pCharacteristic->setValue("ESP32 Beacon");

  // Start the service
  pService->start();

  // Create the BLE Advertising object
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(BEACON_UUID);
  pAdvertising->setScanResponse(true);

  // Set advertising parameters
  pAdvertising->setMinPreferred(0x06);  // Function to change advertising interval
  pAdvertising->setMaxPreferred(0x12);  // Function to change advertising interval

  // Start advertising
  pAdvertising->start();

  Serial.println("BLE Beacon is now advertising...");
}

void loop() {
  // Nothing to do here
}