ESP32 BLE Scan and Advertise at the same time exchanging 2 variables from the device

Hardware Nano Family Nano ESP32
1

I want to scan a device with specific name and get 2 variables advertised by the other device at the same time, the same code will be used in both the device Please find below the code for your ready reference

#if CONFIG_FREERTOS_UNICORE
#define ARDUINO_RUNNING_CORE 0
#else
#define ARDUINO_RUNNING_CORE 1
#endif

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEScan.h>
#include <BLEAdvertisedDevice.h>
#include <BLEAdvertising.h>
// #include <BLEService.h>
#include <BLEServer.h>

#define MAX_DEVICES 5
#define SCAN_DURATION_MS 2
#define MIN_RSSI_THRESHOLD -75 // Adjust this threshold as needed

BLEAdvertising *pAdvertising;

String hostname;

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

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

struct DeviceInfo {
    String hostnameFounded;
    int rssi;
    int variable1;
    int variable2;
};
String hostnameFounded1;
int blerssivalue;

DeviceInfo devices[MAX_DEVICES];
int numDevices = 0;

unsigned long previousScanMillis = 0;
const int scanDurationMs = 500;

void TaskBLEScan( void *pvParameters );


class MyAdvertisedDeviceCallbacks : public BLEAdvertisedDeviceCallbacks {
    void onResult(BLEAdvertisedDevice advertisedDevice) {
        String deviceName = advertisedDevice.getName().c_str();

        if (deviceName.startsWith("ABCD")) {
            // Check if device already exists
            bool found = false;
            for (int i = 0; i < numDevices; i++) {
                if (devices[i].hostnameFounded == deviceName) {
                    found = true;
                    break;
                }
            }

            // Add device if not found
            if (!found && numDevices < MAX_DEVICES) {
                devices[numDevices].hostnameFounded = deviceName;
                devices[numDevices].rssi = advertisedDevice.getRSSI();
                devices[numDevices].variable1 = 1;
                devices[numDevices].variable2 = 10;
                numDevices++;
            }
        }
    }
};

void setup() {
    BLEDevice::init(hostname.c_str());
    pBLEScan = BLEDevice::getScan();
    pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
    pBLEScan->setActiveScan(true);

    BLEDevice::setPower(ESP_PWR_LVL_N12);

    // Create a service and characteristic for advertising
    // BLEService *pService = BLEDevice::createService("0000ffff-0000-1000-8000-00805f9b34fb");
    // BLECharacteristic *pCharacteristic = pService->createCharacteristic("00001111-0000-1000-8000-00805f9b34fb", BLECharacteristic::PROPERTY_READ);
    BLEServer *pServer = BLEDevice::createServer();
    BLEService *pService = pServer->createService(SERVICE_UUID);
    BLECharacteristic *pCharacteristic = pService->createCharacteristic(
                                         CHARACTERISTIC_UUID,
                                         BLECharacteristic::PROPERTY_READ |
                                         BLECharacteristic::PROPERTY_WRITE
                                       );

    // Set the initial values for the characteristic
    pCharacteristic->setValue(String("Variable1: ") + String(variable1.c_str()) + "\nVariable2: " + String(variable2.c_str()));

    // Add the service to the advertising data
    BLEAdvertising* pAdvertising = BLEDevice::getAdvertising();
    pAdvertising->addService(pService);
    pAdvertising->setScanResponse(true); // Optional: Set scan response data
    pAdvertising->start();

    xTaskCreatePinnedToCore(
        TaskBLEScan,
        "AnalogBLEScan",
        1024,  // Stack size
        NULL,
        3,  // Priority
        NULL,
        ARDUINO_RUNNING_CORE);
}

void loop() {
}

void TaskBLEScan(void *pvParameters) {
    (void) pvParameters;
    unsigned long currentMillis = millis();

    for (;;) {
        if (currentMillis - previousScanMillis >= scanDurationMs) {
            BLEScanResults foundDevices = pBLEScan->start(SCAN_DURATION_MS); // Adjust scan time as needed
            // Process detected devices
            int maxRssiIndex = -1;
            int maxRssi = INT_MIN; // Initialize with minimum possible value
            for (int i = 0; i < numDevices; i++) {
                if (devices[i].rssi > MIN_RSSI_THRESHOLD && devices[i].rssi > maxRssi) {
                    maxRssi = devices[i].rssi;
                    maxRssiIndex = i;
                }
            }

            if (maxRssiIndex != -1) {
                Serial.print("Device Nearby: ");
                hostnameFounded1 = devices[maxRssiIndex].hostnameFounded;
                Serial.println(hostnameFounded1);
                Serial.print("RSSI: ");
                blerssivalue = devices[maxRssiIndex].rssi;
                Serial.println(blerssivalue);
                Serial.print("Variable 1: ");
                Serial.println(devices[maxRssiIndex].variable1);
                Serial.print("Variable 2: ");
                Serial.println(devices[maxRssiIndex].variable2);
            }
            //wifirssivalue = WiFi.RSSI();
        }
        numDevices = 0; // Clear detected devices for next scan
        pBLEScan->clearResults();  // delete results fromBLEScan buffer to release memory
        vTaskDelay(50);
    }
}
2

Still Not able to find a solution to exchange data between 2 BLE device. I'm highlighting this for the second time. If someone found the solution please share your thoughts Thanks