Taking more time to connect from NRF to ESP32 BLE Server

[demirschmid61]

Hello sir,

Thank you very much for this wonderful library which reduces the RAM. I am trying to migrate from ArduinoBLE to NimBLE, but facing some issues.

When I am trying to connect from NRF it's taking more time to connect to the ESP32 BLE server compared to ardroidBLE. I have 6 characteristics.

The BLE initialization code snippet is mentioned below
`void initBLE()
{
NimBLEDevice::init("ESP32Server");
NimBLEDevice::setPower(ESP_PWR_LVL_P9);
NimBLEDevice::setMTU(516);

// Create Server
pServer = NimBLEDevice::createServer();

pServer->setCallbacks(new ServerCallBack()); // Set callback for onConnect onDisconnect

// Create Service
createService();
NimBLEAdvertising *pAdvertising = pServer->getAdvertising();

pAdvertising->addServiceUUID(SERVICE_UUID);
pAdvertising->start();
pAdvertising->setScanResponse(true);
pAdvertising->setMinPreferred(0x06);
pAdvertising->setMinPreferred(0x12);
NimBLEDevice::startAdvertising();
}`

The service and characteristic creation code snippet is mentioned below

`void createService()
{
NimBLEService *pService = pServer->createService(SERVICE_UUID);

pCharacteristic1 = pService->createCharacteristic(CHARACTERISTIC_UUID1,
NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::WRITE_NR |
NIMBLE_PROPERTY::WRITE |
NIMBLE_PROPERTY::NOTIFY);
pCharacteristic2 = pService->createCharacteristic(CHARACTERISTIC_UUID2, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic5 = pService->createCharacteristic(CHARACTERISTIC_UUID5, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::NOTIFY);
pCharacteristic3 = pService->createCharacteristic(CHARACTERISTIC_UUID3, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic4 = pService->createCharacteristic(CHARACTERISTIC_UUID4, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic6 = pService->createCharacteristic(CHARACTERISTIC_UUID6, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::WRITE_NR |
NIMBLE_PROPERTY::WRITE |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic7 = pService->createCharacteristic(CHARACTERISTIC_UUID7, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::WRITE_NR |
NIMBLE_PROPERTY::WRITE |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic8 = pService->createCharacteristic(CHARACTERISTIC_UUID8, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::WRITE_NR |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic9 = pService->createCharacteristic(CHARACTERISTIC_UUID9, NIMBLE_PROPERTY::READ |
NIMBLE_PROPERTY::WRITE_NR |
NIMBLE_PROPERTY::NOTIFY);

pCharacteristic1->setCallbacks(&chrCallBack);
pCharacteristic6->setCallbacks(&confCallBack);
pCharacteristic7->setCallbacks(&synchCallback);
pService->start();
}`

Is there anything i am missing?

[h2zero]

You're quite welcome.

The issue could just be the nRF app, there should be no issue on the NimBLE side that can cause this.

[h2zero]

@demirschmid61 have you tried adjusting the advertising interval?