Bluetooth pairing without user confirmation
This need is exactly why createInsecureRfcommSocketToServiceRecord() was added to BluetoothDevice starting in Android 2.3.3 (API Level 10) (SDK Docs)...before that there was no SDK support for this. It was designed to allow Android to connect to devices without user interfaces for entering a PIN code (like an embedded device), but it just as usable for setting up a connection between two devices without user PIN entry.
The corollary method listenUsingInsecureRfcommWithServiceRecord() in BluetoothAdapter is used to accept these types of connections. It's not a security breach because the methods must be used as a pair. You cannot use this to simply attempt to pair with any old Bluetooth device.
You can also do short range communications over NFC, but that hardware is less prominent on Android devices. Definitely pick one, and don't try to create a solution that uses both.
Hope that Helps!
P.S. There are also ways to do this on many devices prior to 2.3 using reflection, because the code did exist...but I wouldn't necessarily recommend this for mass-distributed production applications. See this StackOverflow.
Well, this should really be broken into 2 parts:
- Can you pair 2 Bluetooth devices without going through a Bluetooth pairing handshake? No, you can't. That's baked into the protocol so there is no way around this.
- Can you perform the handshake without a user interface? Yes, you can: that's just code.
I'm not sure how you do it in Windows land, but in *nix land there are functions buried in the Bluez stack that let you receive notifications about when a new device appears, and send it the pairing code (clearly there have to be these functions: those are what the user interface use). Given sufficient time and experience I'm sure you could figure out how to write your own version of the Bluetooth Settings app that somehow:
- Detected a new device had arrived
- Looked at the name/bluetooth mac address and checked some internal database for the pairing code to use.
- Sent the pairing code and completed the operation
All without having to pop up a user interface.
If you go ahead and write the code I'd LOVE to get my hands on it.