How to disconnect BLE when experiment finished?

[donghaipark]

Thank you for your kind reply.

I did close Phyphox, but still not able to connect the ESP32 again unless I reboot the ESP32.

I used the following code for my ESP32:

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

BLEServer* pServer = NULL;
BLECharacteristic* pCharacteristic = NULL;

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

void setup() {
  Serial.begin(115200);
  BLEDevice::init("ESP32");

  // Create the BLE Server
  pServer = BLEDevice::createServer();

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

  // Create a BLE Characteristic
  pCharacteristic = pService->createCharacteristic(
                      CHARACTERISTIC_UUID,
                      BLECharacteristic:ROPERTY_NOTIFY
                    );

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

  // Start advertising
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  BLEDevice:tartAdvertising();
}

void loop() {
    // notify changed value
      int ran = random(0,11); //
      Serial.println(ran);
      pCharacteristic->setValue(ran); //
      pCharacteristic->notify();
      delay(100);
}