主要通信的資料在
Characteristic就叫特征
，特征的值就是我們有交易的資料，
服務下有特征，根據特征值手機和ESP32就能進行資料的通信
下面圖有一個服務和一個特征，服務有uuid,特征有uuid,
在特征内部我們可以讀寫值達到資料通信的目的
手機調試下載下傳URL：
https://apksfull.com/download/no.nordicsemi.android.mcp/3691357
esp32：調式代碼
#include <Arduino.h>
#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>
#define SERVICE_UUID “4fafc201-1fb5-459e-8fcc-c5c9c331914b”
#define CHARACTERISTIC_UUID “beb5483e-36e1-4688-b7f5-ea07361b26a8”
class MyCallbacks: public BLECharacteristicCallbacks {
void onWrite(BLECharacteristic *pCharacteristic) {
std::string value = pCharacteristic->getValue();
if (value.length() > 0) {
Serial.print("\r\nNew value: ");
for (int i = 0; i < value.length(); i++)
Serial.print(value[i]);
Serial.println();
}
};
void setup() {
Serial.begin(9600);
BLEDevice::init(“ESP32 BLE example”);
BLEServer *pServer = BLEDevice::createServer();
BLEService *pService = pServer->createService(SERVICE_UUID);
BLECharacteristic *pCharacteristic = pService->createCharacteristic(
CHARACTERISTIC_UUID,
BLECharacteristic::PROPERTY_READ |
BLECharacteristic::PROPERTY_WRITE
);
pCharacteristic->setCallbacks(new MyCallbacks());
pCharacteristic->setValue(“Hello World”);
pService->start();
BLEAdvertising *pAdvertising = pServer->getAdvertising();
pAdvertising->start();
void loop() {
// put your main code here, to run repeatedly:
//Serial.println(“hi junjun”);
delay(100);
}
在這個不是用IDF的開發，而用arduino開發