用ArduinoBLE函数库写蓝牙传输信息的代码

下面是一个简单的使用ArduinoBLE函数库的蓝牙传输信息的代码：

#include <ArduinoBLE.h>

BLEService service("6E400001-B5A3-F393-E0A9-E50E24DCCA9E");
BLECharacteristic txCharacteristic("6E400002-B5A3-F393-E0A9-E50E24DCCA9E", BLERead | BLENotify, 20);
BLECharacteristic rxCharacteristic("6E400003-B5A3-F393-E0A9-E50E24DCCA9E", BLEWrite, 20);

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

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

  BLE.setLocalName("Arduino BLE");
  BLE.setAdvertisedService(service);

  service.addCharacteristic(txCharacteristic);
  service.addCharacteristic(rxCharacteristic);

  BLE.addService(service);

  rxCharacteristic.setCallbacks(new MyRXCallback());

  BLE.advertise();

  Serial.println("Waiting for connections...");
}

void loop() {
  // do nothing
  delay(1000);
}

class MyRXCallback : public BLECharacteristicCallbacks {
  void onWrite(BLECharacteristic *rxCharacteristic) {
    std::string value = rxCharacteristic->getValue();

    Serial.println(value.c_str());
    txCharacteristic.setValue(value);
    txCharacteristic.notify();
  }
};

请注意，此代码仅用于演示目的，实际使用时应该添加错误检查和处理代码以保护程序免受攻击。