CODEWITHSUNDEEP
androidiosbluetooth
sju
sju

Reputation: 33

Auto connect with already paired BT device

Goal: I'm trying to connect my Android phone to an already paired bluetooth device when its in proximity.

Issue : I am novice to BT technology. I am pairing up my Android phone with a BT device using classic bluetooth API (SPP) as BT device is intent to send large data to mobile app.

The requirement/issue is : Mobile device should automatically connect with already paired BT device when in range. Note that we are using classic BT API and not the GATT.

How does the car audio system automatically connects with driver's phone. I think its the car's BT system who initiate pairing request with phone when car is turn on?

Upvotes: 3

Views: 3807

Answers (2)

sju
sju

Reputation: 33

Yeah by periodic discovery of already paid BT device we can detect and auto pair with them but ar the cost of battery. This is what I had done.

Upvotes: 0

Brian Reinhold
Brian Reinhold

Reputation: 2475

There are a lot of loose ends here. To reconnect to an already paired SPP device depends upon the behavior of the device. If it is passive (always in the slave role) you will have to actively connect to it. I have a passive SPP medical device and to auto reconnect to the device I have to 'continuously' do a discovery in the background (by continuously I mean to a discovery for 5 seconds every 10 seconds or something like that). When I detect the device I create an SPP socket and invoke the connect() method. The alternative is to have a UI that has the user invoke the connect() method when using the device. Hopefully the device is nice and becomes discoverable when it is ready to connect. If it is not discoverable then you need to (yuulk) poll it with connect attempts.

If you have an active device, you can set up a listener socket so the peer can connect to you and you avoid all that background discovery work. At least that is what I have had to deal with.

Upvotes: 1

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