iOS Bluetooth Low Energy Central

01_CentralManager.m

_central = [[CBCentralManager alloc]
                 initWithDelegate:self
                            queue:nil
                          options:nil];
  

02_CentralManagerDelegate.m

- (void)centralManagerDidUpdateState:(CBCentralManager *)central {

  if ([central state] == CBCentralManagerStatePoweredOn) {
    [_central scanForPeripheralsWithServices:@[serviceUUID]
                                     options:nil];
  }

}
  

03_Scanning_and_Discovery.m

NSArray* services = @[serviceUUID];
[_central scanForPeripheralsWithServices:services options:nil];

- (void)centralManager:(CBCentralManager *)central
 didDiscoverPeripheral:(CBPeripheral *)peripheral
     advertisementData:(NSDictionary *)advertisementData
                  RSSI:(NSNumber *)RSSI {
    NSLog(@"Discovered %@", peripheral.name);
}

05_Connecting.m

[_central connectPeripheral:_peripheral options:nil];

- (void)centralManager:(CBCentralManager *)central
  didConnectPeripheral:(CBPeripheral *)peripheral {
      peripheral.delegate = self;
      [peripheral discoverServices:@[serviceUUID]];
}

06_DiscoverServices.m

[peripheral discoverServices:nil];

[peripheral discoverServices:@[serviceUUID]];

07_DidDiscoverServices.m

- (void)peripheral:(CBPeripheral *)peripheral 
  didDiscoverServices:(NSError *)error {

    for (CBService *service in peripheral.services) {
      NSLog(@"Discovered service %@", service);
      NSArray* characteristics = @[switchUUID, dimmerUUID];
      [peripheral discoverCharacteristics:characteristics 
                               forService:service];
    }
    
}

08_DidDiscoverCharacteristics.m

- (void)peripheral:(CBPeripheral *)peripheral 
  didDiscoverCharacteristicsForService:(CBService *)service 
                                  error:(NSError *)error {

  for (CBCharacteristic *characteristic in service.characteristics) {
    NSLog(@"Discovered characteristic %@", characteristic);

      if ([characteristic.UUID isEqual: switchUUID]) {
        _switchCharacteristic = characteristic;
      } else if ([characteristic.UUID isEqual: dimmerUUID]) {
        _dimmerCharacteristic = characteristic;
      }
  }
}

09_ReadCharacteristic.m

[peripheral readValueForCharacteristic:_switchCharacteristic];


- (void)peripheral:(CBPeripheral *)peripheral 
    didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic 
                              error:(NSError *)error {

    if ([characteristic isEqual: _switchCharacteristic]) {
      // get data
    }
}

10_WriteCharacteristic.m

NSData *data = someData;
[_peripheral writeValue:data
      forCharacteristic:_switchCharacteristic
                   type:CBCharacteristicWriteWithResponse];


-(void) peripheral:(CBPeripheral *)peripheral 
   didWriteValueForCharacteristic:(CBCharacteristic *)characteristic 
                            error:(NSError *)error {
      NSLog(@"Wrote value for %@", [characteristic UUID]);
      
}

11_WriteWithoutResponse.m

NSData *data = someData;
[_peripheral writeValue:data
      forCharacteristic:_switchCharacteristic
                   type:CBCharacteristicWriteWithoutResponse];
  

12_Notification.m

[peripheral setNotifyValue:YES forCharacteristic:characteristic];

13_Notification.m

- (void)peripheral:(CBPeripheral *)peripheral
   didDiscoverCharacteristicsForService:(CBService *)service
                                  error:(NSError *)error {

  for (CBCharacteristic *characteristic in service.characteristics) {
    NSLog(@"Discovered characteristic %@", characteristic);
      
      if ([characteristic.UUID isEqual: temperatureUUID]) {
        
        // subscribe for notifications
        [peripheral setNotifyValue:YES forCharacteristic:characteristic];

        // read the current value, so we can update the UI
        [peripheral readValueForCharacteristic: characteristic];

      }
   }
}

14_NotificationCallback.m

- (void)peripheral:(CBPeripheral *)peripheral 
 didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic 
                           error:(NSError *)error {

    if ([characteristic.UUID isEqual: temperatureUUID]) {

        NSData *data = characteristic.value;
        // process
        [_temperatureLabel setText:message];

    }

}