WiFi OLED GIF Display

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

// Apne OBD scanner ka BLE MAC address yahan daalein
static String targetMac = "b2:97:31:1e:55:e4"; 
boolean doConnect = false;
boolean connected = false;
BLEAddress *pServerAddress;
BLEScan* pBLEScan;

// ELM327 BLE Standard UUIDs (Kuch devices ke liye ye fff1/fff2 ya sppp hote hain)
static BLEUUID serviceUUID("0000fff0-0000-1000-8000-00805f9b34fb");
static BLEUUID charUUIDWrite("0000fff1-0000-1000-8000-00805f9b34fb"); 
static BLEUUID charUUIDNotify("0000fff2-0000-1000-8000-00805f9b34fb"); 

BLERemoteCharacteristic* pRemoteCharWrite = nullptr;
BLERemoteCharacteristic* pRemoteCharNotify = nullptr;
bool newDataReceived = false;
String obdResponse = "";

// Notification callback - Jab OBD scanner data wapas bhejega
void notifyCallback(BLERemoteCharacteristic* pBLERemoteCharacteristic, uint8_t* pData, size_t length, bool isNotify) {
    obdResponse = "";
    for (size_t i = 0; i < length; i++) {
        obdResponse += (char)pData[i];
    }
    newDataReceived = true;
}

class MyClientCallbacks : public BLEClientCallbacks {
  void onConnect(BLEClient* pclient) {
    connected = true;
    Serial.println("-> Bluetooth Connected to OBD Scanner Successfully!");
  }

  void onDisconnect(BLEClient* pclient) {
    connected = false;
    Serial.println("-> Bluetooth Disconnected from OBD Scanner!");
  }
};

class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
  void onResult(BLEAdvertisedDevice advertisedDevice) {
    if (advertisedDevice.getAddress().toString() == targetMac) {
      Serial.print("Device Found: ");
      Serial.println(advertisedDevice.toString().c_str());
      
      pServerAddress = new BLEAddress(advertisedDevice.getAddress());
      pBLEScan->stop();
      doConnect = true;
    }
  }
};

bool connectToServer() {
  Serial.print("Connecting to: ");
  Serial.println(pServerAddress->toString().c_str());

  BLEClient* pClient = BLEDevice::createClient();
  pClient->setClientCallbacks(new MyClientCallbacks());

  if (pClient->connect(*pServerAddress)) {
    Serial.println(" - Connected to server");

    // Service aur Characteristics ko dhundhein
    BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
    if (pRemoteService == nullptr) {
      Serial.println("Failed to find OBD service UUID!");
      pClient->disconnect();
      return false;
    }

    pRemoteCharWrite = pRemoteService->getCharacteristic(charUUIDWrite);
    pRemoteCharNotify = pRemoteService->getCharacteristic(charUUIDNotify);

    if (pRemoteCharWrite == nullptr || pRemoteCharNotify == nullptr) {
      Serial.println("Failed to find OBD characteristics!");
      pClient->disconnect();
      return false;
    }

    // Notify enable karein
    if (pRemoteCharNotify->canNotify()) {
      pRemoteCharNotify->registerForNotify(notifyCallback);
    }
    return true;
  } else {
    Serial.println(" - Failed to connect to server");
    return false;
  }
}

void setup() {
  Serial.begin(115200);
  delay(1000);
  Serial.println("ESP32-C3 BLE OBD Scanner Scanning...");

  BLEDevice::init("");
  pBLEScan = BLEDevice::getScan();
  pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
  pBLEScan->setActiveScan(true); 
  pBLEScan->start(5, false);     
}

void loop() {
  if (doConnect == true) {
    if (connectToServer()) {
      Serial.println("Connection process completed.");
    } else {
      Serial.println("Connection failed, restarting scan...");
      doConnect = false;
      pBLEScan->start(5, false); 
    }
    doConnect = false;
  }

  // Jab connected ho tab voltage command bhejein
  if (connected) {
    String cmd = "ATRV\r"; // Battery Voltage Command
    pRemoteCharWrite->writeValue(cmd.c_str(), cmd.length());
    
    unsigned long start = millis();
    newDataReceived = false;
    while (millis() - start < 2000) {
      if (newDataReceived) {
        Serial.print("Battery Voltage: ");
        Serial.println(obdResponse);
        break;
      }
    }
    delay(3000); // Har 3 second me check karein
  } else {
    if (!doConnect) {
      Serial.println("Scanning for OBD Scanner...");
      pBLEScan->start(5, false);
      delay(2000);
    }
  }
}