esp32 与arduino蓝牙通讯

ESP32和Arduino之间的蓝牙通信可以通过使用ESP32作为蓝牙服务器和Arduino作为蓝牙客户端来实现。以下是一个简单的例子，演示了如何在ESP32和Arduino之间进行蓝牙通信：

1. 首先，需要在ESP32上启用蓝牙服务器功能。可以使用Arduino IDE和ESP32的BLE库来实现。以下是一个简单的代码片段，演示了如何在ESP32上启用蓝牙服务器功能：

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

BLEServer* pServer = NULL;
BLECharacteristic* pCharacteristic = NULL;
bool deviceConnected = false;
bool oldDeviceConnected = false;
uint8_t txValue = 0;

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

class MyServerCallbacks: public BLEServerCallbacks {
    void onConnect(BLEServer* pServer) {
      deviceConnected = true;
    };

    void onDisconnect(BLEServer* pServer) {
      deviceConnected = false;
    }
};

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

  BLEDevice::init("ESP32_BLE_Server");
  pServer = BLEDevice::createServer();
  pServer->setCallbacks(new MyServerCallbacks());

  BLEService *pService = pServer->createService(SERVICE_UUID);

  pCharacteristic = pService->createCharacteristic(
                      CHARACTERISTIC_UUID,
                      BLECharacteristic::PROPERTY_READ |
                      BLECharacteristic::PROPERTY_WRITE |
                      BLECharacteristic::PROPERTY_NOTIFY |
                      BLECharacteristic::PROPERTY_INDICATE
                    );

  pCharacteristic->addDescriptor(new BLE2902());

  pService->start();

  BLEAdvertising *pAdvertising = pServer->getAdvertising();
  pAdvertising->addServiceUUID(pService->getUUID());
  pAdvertising->setScanResponse(true);
  pAdvertising->setMinPreferred(0x06);  pAdvertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
  Serial.println("Waiting for a client connection to notify...");
}

void loop() {
  if (deviceConnected) {
    pCharacteristic->setValue(&txValue, 1);
    pCharacteristic->notify();
    txValue++;
    delay(10); // bluetooth stack will go into congestion, if too many packets are sent
  }

  if (!deviceConnected && oldDeviceConnected) {
    delay(500); // give the bluetooth stack the chance to get things ready
    pServer->startAdvertising(); // restart advertising
    Serial.println("start advertising");
    oldDeviceConnected = deviceConnected;
  }

  if (deviceConnected && !oldDeviceConnected) {
    // do stuff here on connecting
    oldDeviceConnected = deviceConnected;
  }
}

2. 接下来，需要在Arduino上编写蓝牙客户端代码。以下是一个简单的代码片段，演示了如何在Arduino上连接到ESP32的蓝牙服务器并发送数据：

#include <SoftwareSerial.h>

SoftwareSerial BTSerial(10, 11); // RX | TX

void setup() {
  Serial.begin(9600);
  BTSerial.begin(9600); // HC-05 default speed in AT command more
}

void loop() {
  if (BTSerial.available()) {
    Serial.write(BTSerial.read());
  }
  if (Serial.available()) {
    BTSerial.write(Serial.read());
  }
}

在这个例子中，Arduino使用SoftwareSerial库将数据发送到ESP32的蓝牙服务器。可以使用Serial Monitor来查看从ESP32返回的数据。