You are using the btSocket variable before it is initialized. On your onCreate Method, try to put this:
try {
outStream = btSocket.getOutputStream();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
after this:
btDevice = btAdapter.getRemoteDevice(address);
try {
btSocket = btDevice.createRfcommSocketToServiceRecord(uuid);
btSocket.connect();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}