BTChat Example Server Does Not Appear on Raspberry Pi

Bruce R

When attempting to run the Bluetooth Chat example between a Windows 10 desktop (Qt 5.11) and a Raspberry Pi (Raspbian GNU/Linux 9 (stretch)) (Qt 5.7), it will connect and run properly when connecting from the RPi to the Windows (i.e. Windows in the server). When attempting to connect from Windows to the RPi, there is no service found.

Looking on the RPi with the command: sdptool records --raw local

I see the following output (reduced to two records) that indicates the program registered the service:

Sequence
	Attribute 0x0000 - ServiceRecordHandle
		UINT32 0x00010007
	Attribute 0x0001 - ServiceClassIDList
		Sequence
			UUID16 0x111f - HandsfreeAudioGateway
			UUID16 0x1203 - GenericAudio
	Attribute 0x0004 - ProtocolDescriptorList
		Sequence
			Sequence
				UUID16 0x0100 - L2CAP
			Sequence
				UUID16 0x0003 - RFCOMM
				UINT8 0x0d
	Attribute 0x0005 - BrowseGroupList
		Sequence
			UUID16 0x1002 - PublicBrowseGroup
	Attribute 0x0009 - BluetoothProfileDescriptorList
		Sequence
			Sequence
				UUID16 0x111e - Handsfree
				UINT16 0x0107
	Attribute 0x0100
		String Hands-Free Voice gateway
	Attribute 0x0301
		UINT8 0x01
	Attribute 0x0311
		UINT16 0x0000
Sequence
	Attribute 0x0000 - ServiceRecordHandle
		UINT32 0x00010008
	Attribute 0x0001 - ServiceClassIDList
		Sequence
			UUID128 e8e10f95-1a70-4b27-9ccf-02010264e9c8
			UUID16 0x1101 - SerialPort
	Attribute 0x0003 - ServiceID
		UUID128 e8e10f95-1a70-4b27-9ccf-02010264e9c8
	Attribute 0x0004 - ProtocolDescriptorList
		Sequence
			Sequence
				UUID16 0x0100 - L2CAP
			Sequence
				UUID16 0x0003 - RFCOMM
				UINT8 0x01
	Attribute 0x0005 - BrowseGroupList
		Sequence
			UUID16 0x1002 - PublicBrowseGroup
	Attribute 0x0009 - BluetoothProfileDescriptorList
		Sequence
			UUID16 0x1101 - SerialPort
	Attribute 0x0100
		String Bt Chat Server
	Attribute 0x0101
		String Example bluetooth chat server
	Attribute 0x0102
		String qt-project.org

When inspecting the Bluetooth services from Windows I see the "Hands-Free Voice Gateway" but not the "Bt Chat Server":

C:\Program Files (x86)\Bluetooth Command Line Tools\bin>btdiscovery -s
(XX:XX:XX:XX:XX:xx)     raspberrypi     Unknown
        1800    0       Generic Access Profile
        1801    0       Generic Attribute Profile
        110E    0       AVRCP CT
        110E    0       AVRCP TG
        110D    0       Audio Source
        1108    12      Headset Voice gateway
        111E    13      Hands-Free Voice gateway
        1134    17      Message Notification
        1134    16      Message Access
        1130    15      Phone Book Access
        1104    14      Synchronization
        1106    10      File Transfer
        1105    9       Object Push
        5005    24      Nokia OBEX PC Suite Services

What needs to be done such that the SDP record for the chat service is visible to remote clients?

xiuscut

had you check in your bt chat server ?
sdptool browse local
:
Service Name: Bt Chat Server
Service Description: Example bluetooth chat server
Service Provider: qt-project.org
Service RecHandle: 0x1000f
Service Class ID List:
UUID 128: e8e10f95-1a70-4b27-9ccf-02010264e9c8
"Serial Port" (0x1101)
Protocol Descriptor List:
"L2CAP" (0x0100)
"RFCOMM" (0x0003)
Channel: 1
Profile Descriptor List:
"Serial Port" (0x1101)
Version: 0x0100

you can see apend the qt bt chat server code :
serviceInfo.setAttribute(QBluetoothServiceInfo::ServiceName, tr("Bt Chat Server"));

when the bt chat client scan ,you should use uuid to find your bt chat server :
m_discoveryAgent->setUuidFilter(uuid); //very inprotant