I am new to bluetooth programming, so please keep that in mind.
I am trying to connect to a pulse sensor from a desktop pc, specifically the Zephyr HxM BT. I am not using any device specific drivers, the Java bluetooth library I'm using is Bluecove, and my bluetooth stack is BlueSoleil.
From my understanding, the way I proceed is
1) Scan for BT devices
public void startSearch() throws BluetoothStateException{
System.out.println("Inquiry started");
localdevice.getDiscoveryAgent().startInquiry(DiscoveryAgent.GIAC, this);
}
This works fine, it discovers my pulse belt and calls
public void deviceDiscovered(RemoteDevice arg0, DeviceClass arg1)
2) Search a device for services
Once a device has been discovered, it should be added to the DiscoveryAgent's list of cached devices, this is my first problem as the cache (and preknown devices) is always empty even though I've discovered my belt.
So the way that I do this now is to either keep my own list of devices, or simply start a service search directly from deviceDiscovered.
I am still a bit unsure if I'm using the correct parameters, but from reading the BT device manual and the javax.bluetooth documentation on DiscoveryAgent.searchServices:
public int searchServices(int[] attrSet,
UUID[] uuidSet,
RemoteDevice btDev,
DiscoveryListener discListener)
throws BluetoothStateException
My code:
public void searchServices(RemoteDevice device){
UUID[] uuidSet = new UUID[1];
uuidSet[0]=new UUID("1101",false); //Serial Port
System.out.println("Searching for services on " + device.getBluetoothAddress() );
try{
agent.searchServices(null,uuidSet, device,this);}
catch (BluetoothStateException e){
System.out.println("BluetoothStateException caught.");
}
}
I've set the attributes parameter to null, because the documentation states that this will have it search for services with the default attributes, however I've also tried to use only ServiceID (0x0003) as attribute with no luck.
This is where I'm stuck, I pass the correct BT device into the function, and it starts searching but never give me any results, it just searches forever for all I know, no exception, no calls to
public void servicesDiscovered(int arg0, ServiceRecord[] arg1)
or
public void serviceSearchCompleted(int arg0, int arg1)
So I guess my questions are: - Am I doing something wrong? Any suggestions? - What are the other approaches to connecting to a BT device, and what information do I have to know about the device to do that?
Here is some information that I think is relevant from the device manual:
The following steps have to be undertaken to connect to a HxM device. 1) Activate the Bluetooth service of the device/computer wanting to connect to the HxM 2) Scan for Bluetooth devices in range 3) Pair with the HxM device found in range 4) Discover Services of Paired HxM 5) Connect to serial port of HxM device
The diagram above shows that the Bluetooth HxM typically communicates with a mobile device over the Bluetooth link. The HxM only supports one link at a time and uses the Bluetooth SPP (Serial Port Profile) to communicate with other devices with the following low-level protocol: • 115,200 baud • 8 data bits • 1 stop bit • No parity
Any suggestions are very much appreciated
edit: I just want to add that I'm testing the code with a console input loop, so the program is not immediately terminated after calling searchServices, it should have time to complete unless I'm misunderstanding async tasks
