Question

if discover a new device then push notification to the user.
how to start and any resources/sample code?

Answer 1

All three previous answers are incorrect. iOS5 introduced Core Bluetooth framework.

However, this framework is BT 4.0 LE only; none-the-less Bluetooth.

Here also is the PDF reference: http://developer.apple.com/library/ios/documentation/CoreBluetooth/Reference/CoreBluetooth_Framework/CoreBluetooth_Framework.pdf

Example

Your class must conform to the CBCentralManagerDelegate and CBPeripheralDelegate protocols.

CBCentralManager * btCentral = [[CBCentralManager alloc] initWithDelegate:self queue:nil];

/* Create an array of services from a CBUUID to scan for */
[btCentral scanForPeripheralsWithServices:nil options:nil];

That’s basically to get you started on scanning for peripherals. You will also need to implement the CBCentralManagerDelegate methods and a few others, I suggest reading the docs:

- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI

- (void)centralManager:(CBCentralManager *)central didRetrieveConnectedPeripherals:(NSArray *)peripherals