iphone - iOS Core Bluetooth Not asking for Pair -

in recent project, need communicate hardware (bluetooth low energy).i have implement delegate methods code. able connect hardware , device, not getting pairing alert (attached screen shot). why not asking pairing? thank you.

  #import "btwcentralconnectionmanager.h"      @implementation btwcentralconnectionmanager      @synthesize cbcmanager;      @synthesize discoveredperipheral;      @synthesize findmeservicecharacteristic;      @synthesize findmeservice;      @synthesize delegate=_delegate;      static nsstring *kfindmeserviceuuid=@"1802";      static nsstring *kfindmecharacteristicuuid=@"2a06";      static btwcentralconnectionmanager* connectionmanager = nil;      +(btwcentralconnectionmanager *)sharedconnectionmanager{      @synchronized(self)      {          if (!connectionmanager){              connectionmanager=[[self alloc] init];           }          return connectionmanager;      }      return nil;  }       -(void)findme {      byte code=0x02;      if(self.discoveredperipheral){          [self.discoveredperipheral writevalue:[nsdata datawithbytes:&code length:1] forcharacteristic:self.findmeservicecharacteristic type:cbcharacteristicwritewithoutresponse];       }else{          uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:@"invalid charactersitcs" delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];          [alertview show];          alertview=nil;      } }  -(void)searchfordevices{      self.cbcmanager=[[cbcentralmanager alloc] initwithdelegate:self queue:nil];  }      -(void)connect {      nsdictionary* connectoptions = [nsdictionary dictionarywithobject:[nsnumber numberwithbool:yes] forkey:cbconnectperipheraloptionnotifyondisconnectionkey];       [self.cbcmanager connectperipheral:self.discoveredperipheral options:connectoptions];  }      -(void)disconnect{      [self cleanup];  }   - (void)centralmanagerdidupdatestate:(cbcentralmanager *)central {      switch (central.state) {          case cbcentralmanagerstatepoweredon:{              [self.cbcmanager scanforperipheralswithservices:@[ [cbuuid uuidwithstring:kfindmeserviceuuid] ] options:@{cbcentralmanagerscanoptionallowduplicateskey : @no }];          }              break;              // scans peripheral          default:{              uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:@"cental manager did change state" delegate:nil cancelbuttontitle:nil otherbuttontitles:@"ok", nil];              [alertview show];              alertview=nil;          }              break;     }  }   - (void)centralmanager:(cbcentralmanager *)central diddiscoverperipheral:(cbperipheral *)peripheral advertisementdata:(nsdictionary *)advertisementdata rssi:(nsnumber *)rssi {      // stops scanning peripheral      [self.cbcmanager stopscan];       if (self.discoveredperipheral != peripheral) {          self.discoveredperipheral = peripheral;          [self.delegate diddevicediscoverd:self.discoveredperipheral.name];      }  }  - (void)centralmanager:(cbcentralmanager *)central didfailtoconnectperipheral:(cbperipheral *)peripheral error:(nserror *)error {      [self.delegate diddeviceconnectionfailed:error];      [self cleanup]; }   - (void)centralmanager:(cbcentralmanager *)central didconnectperipheral:(cbperipheral *)peripheral {      [self.delegate diddeviceconnected];      [self.discoveredperipheral setdelegate:self];      [self.discoveredperipheral discoverservices:@[[cbuuid uuidwithstring:kfindmeserviceuuid]]];  }   - (void)peripheral:(cbperipheral *)aperipheral diddiscoverservices:(nserror *)error {      if (error) {          nsstring *strmsg=[nsstring stringwithformat:@"diddiscoverservices: %@",  error];          uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg  delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];          [alertview show];          alertview=nil;          [self cleanup];          return;      }      (cbservice *service in aperipheral.services) {          if ([service.uuid isequal:[cbuuid uuidwithstring:kfindmeserviceuuid]]) {              self.findmeservice=service;              [self.discoveredperipheral discovercharacteristics:@[[cbuuid uuidwithstring:kfindmecharacteristicuuid]] forservice:self.findmeservice];          }      }  }  - (void) peripheral:(cbperipheral *)peripheral diddiscovercharacteristicsforservice:(cbservice *)service error:(nserror *)error {      if(error){          nsstring *strmsg=[nsstring stringwithformat:@"diddiscovercharacteristicsforservice: %@",  error];          uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];          [alertview show];          alertview=nil;      }      for(cbcharacteristic *character in [service characteristics])     {          if([[service uuid] isequal:[cbuuid uuidwithstring:kfindmeserviceuuid]] &&            [[character uuid] isequal:[cbuuid uuidwithstring:kfindmecharacteristicuuid]])         {              nsstring *strmsg=[nsstring stringwithformat:@"diddiscovercharacteristicsforservice: %@",  character];              uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];              [alertview show];              alertview=nil;              self.findmeservicecharacteristic = character;          }     } }   - (void) peripheral:(cbperipheral *)peripheral didupdatevalueforcharacteristic:(cbcharacteristic *)characteristic error:(nserror *)error  {      nsstring *strmsg=[nsstring stringwithformat:@"did update value characteristic %@, new value: %@, error: %@", characteristic, [characteristic value], error];      uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];      [alertview show];      alertview=nil;   }  - (void)peripheral:(cbperipheral *)peripheral didupdatenotificationstateforcharacteristic:(cbcharacteristic *)characteristic error:(nserror *)error {      if (error) {          nslog(@"error changing notification state: %@", error.localizeddescription);      }       // exits if it's not transfer characteristic      if (![characteristic.uuid isequal:[cbuuid uuidwithstring:kfindmecharacteristicuuid]]) {          return;      }       nsstring *strmsg=[nsstring stringwithformat:@"didupdatenotificationstateforcharacteristic %@, reason: %@", characteristic, error];      uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];      [alertview show];       alertview=nil;  }  - (void) peripheral:(cbperipheral *)peripheral didwritevalueforcharacteristic:(cbcharacteristic *)characteristic error:(nserror *)error  {      if (error)      {          nsstring *strmsg=[nsstring stringwithformat:@"failed write value characteristic %@, reason: %@", characteristic, error];          uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];          [alertview show];          alertview=nil;      }     else     {         nsstring *strmsg=[nsstring stringwithformat:@"did write value characterstic %@, new value: %@", characteristic, [characteristic value]];          uialertview *alertview=[[uialertview alloc] initwithtitle:@"test" message:strmsg delegate:nil cancelbuttontitle:nil     otherbuttontitles:@"ok", nil];          [alertview show];          alertview=nil;      } }  - (void)cleanup  {      if (!self.discoveredperipheral.isconnected) {          return;      }      if (self.discoveredperipheral.services != nil) {          (cbservice *service in self.discoveredperipheral.services) {              if (service.characteristics != nil) {                  (cbcharacteristic *characteristic in service.characteristics) {                      if ([characteristic.uuid isequal:[cbuuid uuidwithstring:kfindmeserviceuuid]]) {                          if (characteristic.isnotifying) {                              [self.discoveredperipheral setnotifyvalue:no forcharacteristic:characteristic];                              return;                          }                      }                  }              }         }     }     [self.cbcmanager cancelperipheralconnection:self.discoveredperipheral];     [self.delegate diddevicedisconnected]; } @end ` 

if understand right can write value characteristic don't pairing request.

the pairing triggered peripheral. meaning peripheral has refuse write or read request of central characteristic. central gets refusal "unauthorized authentication" , tries pair peripheral , showing pairing alert pop waiting for. done core bluetooth automatically. thing need change characteristics options , permissions in peripheral. apple sample code trigger pairing:

emailcharacteristic = [[cbmutablecharacteristic alloc]     initwithtype:emailcharacteristicuuid     properties:cbcharacteristicpropertyread     | cbcharacteristicpropertynotifyencryptionrequired     value:nil permissions:cbattributepermissionsreadencryptionrequired]; 

source: corebluetooth_concepts ios7 preview

also check out wwdc 2012 advanced core bluetooth video @ 28 minutes explain concept of pairing.