ESP32蓝牙多点怎么用

ESP32可以通过使用BLE（低功耗蓝牙）协议来实现蓝牙多点连接。以下是实现步骤：

1. 初始化 BLE

使用 `BLEDevice::init()` 函数初始化BLE设备。

#include <BLEDevice.h>

void setup() {
  BLEDevice::init("ESP32");
}

2. 创建 BLE Service 和 Characteristic

使用 `BLEService` 和 `BLECharacteristic` 类来创建BLE服务和特征值。

#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>

// BLE Service UUID
#define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
// BLE Characteristic UUID
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

BLECharacteristic *pCharacteristic;

void setup() {
  BLEDevice::init("ESP32");

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

  // Create a BLE Service
  BLEService *pService = pServer->createService(SERVICE_UUID);

  // Create a BLE Characteristic
  pCharacteristic = pService->createCharacteristic(
                      CHARACTERISTIC_UUID,
                      BLECharacteristic::PROPERTY_READ |
                      BLECharacteristic::PROPERTY_WRITE |
                      BLECharacteristic::PROPERTY_NOTIFY |
                      BLECharacteristic::PROPERTY_INDICATE
                    );

  // Set the value of the characteristic
  pCharacteristic->setValue("Hello World");

  // Add a descriptor to the characteristic
  pCharacteristic->addDescriptor(new BLE2902());

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

  // Start advertising
  pServer->getAdvertising()->start();
}

3. 处理 BLE 连接事件

使用 `BLEServerCallbacks` 和 `BLECharacteristicCallbacks` 类来处理BLE连接事件。

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

class MyServerCallbacks : public BLEServerCallbacks {
    void onConnect(BLEServer* pServer) {
      // Handle a new client connection
    }

    void onDisconnect(BLEServer* pServer) {
      // Handle a client disconnection
    }
};

class MyCharacteristicCallbacks : public BLECharacteristicCallbacks {
    void onWrite(BLECharacteristic *pCharacteristic) {
      // Handle a write event
    }

    void onRead(BLECharacteristic *pCharacteristic) {
      // Handle a read event
    }
};

void setup() {
  BLEDevice::init("ESP32");

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

  // Set the server callbacks
  pServer->setCallbacks(new MyServerCallbacks());

  // ...

  // Set the characteristic callbacks
  pCharacteristic->setCallbacks(new MyCharacteristicCallbacks());

  // ...

  // Start advertising
  pServer->getAdvertising()->start();
}

这样，ESP32就可以同时连接多个BLE设备并处理它们之间的交互。