Bluetooth Integration
Building Bridges to Bluetooth Enabled Peripherals
Ryan McMahan • Senior Software Engineer
Shared Technology • Intermec
Presentation Focus
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Code
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Tight Integration with Your App
Wireless Printing
Wireless Scanning
Microsoft APIs
Multiblue
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A sample application
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Bluetooth Printing setup
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Switching printers
Bluetooth Scanning setup
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Scanner setup via ISCP
(Intermec Scanner Control Protocol)
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Device Discovery
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Found device event
Scanning
Printing
Multiblue – Application Flow
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Startup
Scanner setup
Printer setup
Scan
Print
Switch printers
Print
Shutdown
Multiblue - Startup
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Turn the radio on
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Intermec Bluetooth Library
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IBT_On()
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Available in Intermec Developer
Library (IDL)
Why would you leave it off?
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Power savings
Security policies
No radio zones
Be a Good Radio Citizen
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Try to maintain the previous radio state
when exiting your app
Knowing when not to turn off is easier
than knowing when it is safe to turn off
Intermec APIs for Bluetooth
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IBT_On
IBT_Off
Multiblue – Scanner Setup
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Add to Data Collection – Handles all of the
connection maintenance
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Related session – “Accelerating Development with the
Intermec Data Collection Engine”
COM port connections are possible as well
How do we know which scanner to connect to?
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Device Address is the key for connections
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Device Discovery
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Barcode scan
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Read from a file
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Manually entry
Avoiding Device Discovery
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Very powerful and useful
Can take longer than you’d like, especially in
populated areas
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Inquiry is traditionally fixed (approximately 10s)
Device name lookup is variable (0-10s) and
handled one device at a time
You can skip name lookup, but results are
less valuable
Approximate total time in seconds
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10 + (num_devices * 3)
Barcode Scan
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Scanner – SF51
Route Printer – PB41
Depot Printer – PB42
Reading Local Device Address
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3 Steps
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Initialize Winsock
Create and bind a socket
getsockname()
Reading Local Device Address
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Step 1: Initialize Winsock
WSADATA wsaData;
WORD wVer = MAKEWORD( 2, 2 );
if(WSAStartup(wVer, &wsaData) != 0)
AfxMessageBox(_T("Could not initialize"));
Reading Local Device Address
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Step 2: Create and bind a socket
SOCKET s = socket(AF_BTH, SOCK_STREAM,
BTHPROTO_RFCOMM);
SOCKADDR_BTH sab;
memset(&sab, 0, sizeof(sab));
sab.addressFamily = AF_BTH;
sab.port = 0;
int len = sizeof(sab);
bind(s, (sockaddr *)&sab,len);
Reading Local Device Address
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Step 3: getsockname
if(0 == getsockname(s, (sockaddr *)&sab, &len))
code.Format(_T("%04x%08x"), GET_NAP(sab.btAddr),
GET_SAP(sab.btAddr));
closesocket(s);
code.MakeUpper();
m_cDeviceAddress.SetWindowText(code);
Live Display
• Bluetooth Scanner in Intermec Settings
Multiblue – Printer Setup
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Prepare two printers – one COM port
How do we know which printer to connect to?
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Device Address is the key for connections
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Device Discovery
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Barcode scan – leverage our scanner connection
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Read from a file
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Manually entry
Printer Self-test
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Contains useful setup information
Newer products contain a Code 128 representation
of the Bluetooth Device Address
Device Address Separators
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Common separator forms
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AA:BB:CC:11:22:33
AA.BB.CC.11.22.33
AA-BB-CC-11-22-33
AA BB CC 11 22 33
Good for humans, less interesting to computers
Suggestion – include code to filter out device
address separators
Barcode Scan
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Code Note: I modify the postamble
Route Printer – PB41
Depot Printer – PB42
COM Port Registration
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Things You Need
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Could be on different COM ports
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Remote Device Address
Port index – COM6 is a good choice
Port prefix – COM or BSP
Service UUID or RFCOMM channel
We’ll make them share to illustrate deregistration
The dreaded 2404
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The device is in use by an active process and cannot be
disconnected.
Something is already registered on that port
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Choose another port or deregister
Registration Code
PORTEMUPortParams pp;
TCHAR prefix[3+1];
// COM or BSP
pp.device = bdaddr;
pp.channel = 0;
// Let it auto-SDP
memcpy(&pp.uuidService,
&SerialPortServiceClass_UUID, sizeof(GUID));
tcscpy(prefix, L"COM");
int index = 6;
hBluetoothPort = RegisterDevice(prefix, index,
L"btd.dll", (DWORD)&pp);
Deregistration Code
DeregisterDevice(hBluetoothPort);
COM Port APIs
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Same as traditional COM Ports
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CreateFile & CloseFile
ReadFile & WriteFile
GetCommMask & SetCommMask
GetCommState & SetCommState
WaitCommEvent
DCB Structure
Be careful with uiportflags parameter
Confirmation Print
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Common technique to verify setup
It can be bad
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Requires printer to be in range and turned on
Could be wasteful depending on frequency of
setup and app design
Device Discovery
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Background thread to detect location
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Allows us to auto-switch the default printer
Bluetooth GPS is perfect for this
Multiblue will use this to recognize when
our depot printer is ready
Device Discovery Code
iRet = WSALookupServiceBegin (&wsaq, LUP_CONTAINERS, phLookup);
<loop on WSALookupServiceNext>
iRet = WSALookupServiceNext(*phLookup, LUP_RETURN_ADDR, &dwSize,
pwsaResults);
if(iRet == ERROR_SUCCESS)
{
wsprintf(szDevice, _T("%04x%08x"),
GET_NAP(((SOCKADDR_BTH *)pwsaResults->lpcsaBuffer>RemoteAddr.lpSockaddr)->btAddr),
GET_SAP(((SOCKADDR_BTH *)pwsaResults->lpcsaBuffer>RemoteAddr.lpSockaddr)->btAddr));
RETAILMSG(1,(_T("\r\n %s"), szDevice));
if(_tcsicmp(szDevice, me->m_printer2) == 0)
{
found = TRUE;
RETAILMSG(1,(_T("\r\n DING! Match on %s"), szDevice));
}
}
WSALookupServiceEnd(phLookup);
Demo
• Multiblue in action
Learn More
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Bluetooth Resource Kit in Intermec Developer Library
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Microsoft’s Sample Program
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Wp_sample2
Btsearch
Installs as part of the Pocket PC 2003 SDK
\Program Files\Windows CE Tools\wce420\Pocket PC
2003\Samples\Win32\Bluetooth
Windows Embedded Source Tools for Bluetooth
Technology
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A Win32 API Wrapper that developers can expose in Visual
Studio .NET or the .NET Compact Framework
Questions?
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Yes, I will make this code available