×
Namespaces

Variants
Actions
Revision as of 05:09, 10 May 2012 by hamishwillee (Talk | contribs)

Advertising Bluetooth services using Symbian C++

From Nokia Developer Wiki
Jump to: navigation, search
Article Metadata
Tested with
Devices(s): Nokia N95
Compatibility
Platform(s): S60 3rd Edition, MR
S60 3rd Edition FP1
Article
Keywords: RSdp, RSdpDatabase, TSdpServRecordHandle, RSdpDatabase::CreateServiceRecordL(), RSdpDatabase::UpdateAttributeL()
Created: tepaa (25 Apr 2008)
Last edited: hamishwillee (10 May 2012)

Contents

Overview

RSdp provides a session to the Service Discovery Database. It is used to create subsessions to database functionality. A client must create and connect a session before using a RSdpDatabase subsession to access the database.

RSdpDatabase is a subsession of the SDP through which service records and their attributes can be added, deleted, and updated.

The following example shows how to advertise a certain (KBT_serviceID 0x10ff) Bluetooth service. Discovering this particular service is explained in Discovering Bluetooth services using Symbian C++.

Listening to the Bluetooth connection is explained in CS000939 - Establishing a Bluetooth connection. The channel number parameter in CMyServiceAdvertiser::StartAdvertiserL(TInt aChannel) method comes there.

MMP file

The following capabilities and libraries are required:

CAPABILITY LocalServices
LIBRARY sdpagent.lib
LIBRARY sdpdatabase.lib

Header file

#include <btsdp.h>
#include <bt_sock.h>
 
// The service id that identifies the service. This id will be
// used when advertising the service and discovering the service.
#define KBT_serviceID 0x10ff
 
// Service name and description for our service
_LIT(KBTServiceName, "BTpmp");
_LIT(KBTServiceDesc, "BTpmp");
 
// Service discovery protocol session
RSdp iSdp;
 
// Service discovery database (sdp)
RSdpDatabase iSdpDB;
 
// Service record
TSdpServRecordHandle iRecord;
 
// Service record state
TInt iRecordState;

Source file

Start the service advertiser on a given channel. Entry to service discovery database will be entered describing the advertised service.

void CMyServiceAdvertiser::StartAdvertiserL(TInt aChannel)
{
// Open sdp session
User::LeaveIfError(iSdp.Connect());
// Open sdp database session
User::LeaveIfError(iSdpDB.Open(iSdp));
 
// Create a record of the correct service class
TUUID serviceUUID(KBT_serviceID);
iSdpDB.CreateServiceRecordL(serviceUUID, iRecord);
 
// Add a protocol to the record
CSdpAttrValueDES* protocolDescriptorList = CSdpAttrValueDES::NewDESL(NULL);
CleanupStack::PushL(protocolDescriptorList);
 
TBuf8<1> channel;
channel.Append((TChar)aChannel);
 
// Create protocol list for our service
protocolDescriptorList
->StartListL() // list of protocols required for this method
->BuildDESL()
->StartListL()
->BuildUUIDL(KL2CAP)
->EndListL()
 
->BuildDESL()
->StartListL()
->BuildUUIDL(KRFCOMM)
->BuildUintL(channel)
->EndListL()
->EndListL();
 
// Set protocol list to the record
iSdpDB.UpdateAttributeL(iRecord, KSdpAttrIdProtocolDescriptorList,
*protocolDescriptorList);
CleanupStack::PopAndDestroy(protocolDescriptorList);
 
// Add a name to the record
iSdpDB.UpdateAttributeL(iRecord,
KSdpAttrIdBasePrimaryLanguage +
KSdpAttrIdOffsetServiceName,
KBTServiceName);
 
// Add a description to the record
iSdpDB.UpdateAttributeL(iRecord,
KSdpAttrIdBasePrimaryLanguage +
KSdpAttrIdOffsetServiceDescription,
KBTServiceDesc);
 
// Set service available
UpdateAvailabilityL(ETrue);
}

Set the availability of the advertised service. The service record on the service discovery database will be updated accordingly.

void CMyServiceAdvertiser::UpdateAvailabilityL(TBool aAvailable)
{
TInt state = aAvailable ? 0xFF : 0x00;
 
// Set availability
iSdpDB.UpdateAttributeL(iRecord, KSdpAttrIdServiceAvailability, state);
 
// Mark record changed
iSdpDB.UpdateAttributeL(iRecord, KSdpAttrIdServiceRecordState,
++iRecordState);
}

Stop advertising the service

void CMyServiceAdvertiser::StopAdvertiserL()
{
if ( iRecord!=NULL )
{
// Delete record from service discovery database
iSdpDB.DeleteRecordL(iRecord);
 
// Close sdp and sdp db sessions
iSdpDB.Close();
iSdp.Close();
iRecord=NULL;
}
}


Postconditions

The Bluetooth service is advertised and can be discovered as explained in Discovering Bluetooth services using Symbian C++.

See also

Discovering Bluetooth devices using Symbian C++

Discovering Bluetooth services using Symbian C++

CS000939 - Establishing a Bluetooth connection

RHostResolver and redundant display of access point selection dialog (Known Issue)

Example application

This code snippet has been used in the S60 Platform: Bluetooth Point-to-multipoint Example application.

94 page views in the last 30 days.
×