Android Question Can you have different BT-profiles active between two devices at the same time?

[moster67]

From this thread Erel said:

You cannot emulate a headset with an Android device. The only Bluetooth profile accessible for developers is the SPP profile (serial port profile).
You can create an app that is installed on both devices and then communicates between them. It is pretty simple.

OK, I have understood that part. I have tried the demo-app (chat app) posted by Erel in this thread and it works fine between two android phones.

Now, I have this android head-unit in my car running ICS 4.03 and there is already an existing and working bluetooth connection between my phone and the head-unit. The BT for this connection is "Call audio", "Media Audio" and "Contact access".

I now installed the BT sample app on the Head Unit and tried to get the chat app working so I could chat with the chat-app on my phone but it did not work out well. The devices are discovered but cannot connect. Is this because there is already an existing connection (pairing) between them and/or different BT-profiles cannot be used at the same (with chat-app = SPP profile)? Perhaps, I can simply check if they are connected and then use the chat-code? I have not yet tried this and I thought I would ask before if this is even possible for obvious reasons.

Thanks.

 

[Erel]

Bluetooth does support multiple connections.

What is the Head Unit? Is this an Android device?

 

[moster67]

Yes, the Head Unit is an Android device running ICS 4.03.

The Head Unit is already paired with my phone and connection takes place successfully as soon as I enter the car. Now, I'd like to use the SPP-profile (the chat-demo was the code I tried as an example) to let the Head Unit communicate with my phone over BT so some code can be executed on the phone. I will be using two services on each device. At the same time, I still need that the already existing profiles continue to work since they are responsabile for phone-calls etc.

If above scenario is possible with BT, I think my idea is to check if the devices are already connected (which they should be although they have probably established a connection using a different profile). If they are connected, then the Head Unit should communicate with my phone using the SPP profile.

Is this feasible?

 

[Erel]

Theoretically it should be possible. Do know that Bluetooth is not perfect on some Android devices.

You can add an intent filter that listens to android.bluetooth.device.action.ACL_CONNECTED action to be notified when a Bluetooth is connected.