使用ESP 32 BLE

Question

我正在尝试使用ESP32对BLE客户端进行编程。我使用了附件代码（这是示例部分中的示例代码）。我现在的问题是，如何仅显示扫描设备的MAC地址，以及如何将此MAC地址更改为JSON格式以进行Lora芯片进行传输？非常感谢您的时间阅读这篇文章。

/*
   Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleScan.cpp
   Ported to Arduino ESP32 by Evandro Copercini
*/

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEScan.h>
#include <BLEAdvertisedDevice.h>

int scanTime = 5; //In seconds
BLEScan* pBLEScan;

class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
    void onResult(BLEAdvertisedDevice advertisedDevice) {
      Serial.printf("Advertised Device: %s \n", advertisedDevice.toString().c_str());
    }
};

void setup() {
  Serial.begin(115200);
  Serial.println("Scanning...");

  BLEDevice::init("");
  pBLEScan = BLEDevice::getScan(); //create new scan
  pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
  pBLEScan->setActiveScan(true); //active scan uses more power, but get results faster
  pBLEScan->setInterval(100);
  pBLEScan->setWindow(99);  // less or equal setInterval value
}

void loop() {
  // put your main code here, to run repeatedly:
  BLEScanResults foundDevices = pBLEScan->start(scanTime, false);
  Serial.print("Devices found: ");
  Serial.println(foundDevices.getCount());
  Serial.println("Scan done!");
  pBLEScan->clearResults();   // delete results fromBLEScan buffer to release memory
  delay(2000);
}

Answer 1

扫描的结果是fintdevices，其中包含所有已找到设备的列表。我们可以迭代以访问设备。该列表包含 getAddress（）。地址可以使用toString（）转换为字符串。您可以打印字符串或将其放入JSON容器中。

您的循环代码看起来像这样：

void loop() {
  // put your main code here, to run repeatedly:
  BLEScanResults foundDevices = pBLEScan->start(scanTime, false);
  Serial.print("Devices found: ");
  for (int i = 0; i < foundDevices.getCount(); ++i)
  {
    std::string address = foundDevices.getDevice(i).getAddress().toString();
    int rssi = foundDevices.getDevice(i).getRSSI();
    Serial.print(address.c_str());
    Serial.print(rssi);
    // TODO: Insert into JSON
  }
  Serial.println(foundDevices.getCount());
  Serial.println("Scan done!");
  pBLEScan->clearResults();   // delete results fromBLEScan buffer to release memory
  delay(2000);
}