Bluetooth Low EnergyUncovered
Gabe Gindele@barbazoo
Friday, October 18, 13
Tech Overview
• “A Better Bluetooth” - Power and Cost
• 4.0 - Single and Dual Mode
• 3 Advertising, 37 Data Channels
• Advertiser vs. Scanner
• Master vs. Slave
Friday, October 18, 13
Classic vs. Low Energy
• 100mW vs. 10mW power
• Connection Oriented vs. Connectionless
• Streaming Data vs. Small Data Bursts
• HCI API stays intact
Friday, October 18, 13
Tech Overview Cont.
Total Transaction Time: 3msFriday, October 18, 13
Apple and Bluetooth LE
• First to Introduce
• iPhone 4S, MBA, Mac Mini since 2011
• WWDC 2012 Sessions
• All Products Today - Apple TV
• Classic remains under MFA
• Opens new era of Sensors and IOT
Friday, October 18, 13
Devices Today
• Fitbit Flex
• Heart Rate monitors
• SmartWatches
• Proximity
• iBeacons
• Sensors
Friday, October 18, 13
GATT
• Service
• Characteristic
• Value
• Descriptors
• Notifications
• APIs are Asynchronous
Friday, October 18, 13
iOS: Discovery
central = [[CBCentralManagernager alloc]
initWithDelegate:self queue:nil];
[central scanForPeripheralsWithServices:nil options:nil];
-‐ (void)centralManager:(CBCentralManager *)central
didDiscoverPeripheral:(CBPeripheral *)peripheral
advertisementData:(NSDictionary *)advertisementData
RSSI:(NSNumber *)RSSI {}
[myCentralManager stopScan];
Friday, October 18, 13
iOS: Connection
[myCentralManager connectPeripheral:peripheral options:nil];
-‐ (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {}
peripheral.delegate = self;
[peripheral discoverServices:nil];[peripheral discoverCharacteristics:nil forService:...];
[peripheral readValueForCharacteristic:...];[peripheral setNotifyValue:YES forCharacteristic:...;[peripheral writeValue:... type:CBCharacteristicWriteWithResponse]
Friday, October 18, 13
Android: BluetoothGatt
• Since 4.3 - API 18 - Most of new devices
• A new profile
• GATT Server is missing
Friday, October 18, 13
Android: Discovery
mBluetoothAdapter.startLeScan(mLeScanCallback);
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {};
mBluetoothAdapter.stopLeScan(mLeScanCallback);
Friday, October 18, 13
Android: Connection
BluetoothGatt mBtGatt = device.connectGatt(... callback);
BluetoothGattCallback callback = new BluetoothGattCallback() {
public void onConnectionStateChange(...) {}public void onServicesDiscovered(...) {}public void onCharacteristicRead(...) {}public void onCharacteristicChanged(...) {}
};
mBtGatt.setCharacteristicNotification(characteristic, enabled);
onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic) {}
Friday, October 18, 13
iBeacon
• Best Kept Secret of iOS7
• Micro Locations Made Simple
• API extends CoreLocation - CLBeacon
• Broadcast only - UUID, Major, Minor
• Geofence, Passbook
Friday, October 18, 13
Development Tools
• TI CC2541 Sensor Tag
• BlueGiga BGScript and API
• Nordic nRF51922 with Cortex M0
• RadiusNetworks Android iBeacons SDK
Friday, October 18, 13
Questions?
Friday, October 18, 13
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