Raspberry Pi Bluetooth: Enable legacy pairing / connection without PIN input

Question

For a few days I'm desperately trying to configure Bluetooth legacy pairing on my Raspberry Pi. Unfortunately I hadn't had any success until today. I tried countless tutorials/posts on several forums but no one worked.

Can anyone give me an up to date method that worked in your case? I noticed that almost all posts about this topic are at least 2 years old, which doesn't make it easier to get to a solution.

Thanks in advance.

Answer 1

Assuming you want to do this from the command line, all you need to do is launch bluetoothctl with no input/no output capabilities. See below the recommended sequence of commands:-

sudo btmgmt power off
sudo btmgmt discov on
sudo btmgmt connectable on
sudo btmgmt pairable on
sudo btmgmt power on
sudo btmgmt io-cap 3

The last command sets your IO capabilities to NoInputNoOutput, and the numberical values correspond to the following:-

0       DisplayOnly
1       DisplayYesNo
2       KeyboardOnly
3       NoInputNoOutput
4       KeyboardDisplay

Finally, launch bluetoothctl as follows:-

bluetoothctl --agent NoInputNoOutput

Some references:-

• Raspberry Pi BLE pairing/encryption
• What Bluetoothctl agents are there
• bluetoothctl set passkey