Pair Bluetooth Controllers - manual setup

First ensure that Bluetooth is enabled on your device. First, the line controllers.bluetooth.enabled=1 should be present in your system/batocera.conf file and not commented out (how to access the batocera.conf file). If it is missing, add it in. Note that doing this won't suddenly make a non-functional Bluetooth dongle start working, only the ones that are already compatible with the Linux kernel and the drivers included in Batocera.

Establish an SSH connection (or open up Xterm) to start the manual connection process. Get started by typing bluetoothctl and hitting [Enter].

Now you are in the Bluetooth control unit. Type following commands and confirm every single one with [Enter]

agent on
default-agent
power on
scan on

Now set the controller in pairing mode! This strongly depends from your controller type.

An example of the output you would see from running all the commands successfully:

[root@BATOCERA /userdata/system]# bluetoothctl
Agent registered
[bluetooth]# agent on
Agent is already registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# power on
Changing power on succeeded
[bluetooth]# scan on
Discovery started
[CHG] Controller 43:45:C0:00:1F:AC Discovering: yes
[NEW] Device E4:17:D8:C2:0B:0E 8BitDo M30 Modkit

Now we want to connect to our controller. So we type following commands to connect to discovered controller with MAC address E4:17:D8:C2:0B:0E properly. Wait a few seconds after entering the commands in order to ensure they are processed successfully.

  pair E4:17:D8:C2:0B:0E
  connect E4:17:D8:C2:0B:0E
  trust E4:17:D8:C2:0B:0E

This would be the output from our example:

 [bluetooth]# pair E4:17:D8:C2:0B:0E
 Attempting to pair with E4:17:D8:C2:0B:0E
 [CHG] Device E4:17:D8:C2:0B:0E Connected: yes
 [CHG] Device E4:17:D8:C2:0B:0E Modalias: usb:v2DC8p5101d0100
 [CHG] Device E4:17:D8:C2:0B:0E UUIDs: 00001124-0000-1000-8000-00805f9b34fb
 [CHG] Device E4:17:D8:C2:0B:0E UUIDs: 00001200-0000-1000-8000-00805f9b34fb
 [CHG] Device E4:17:D8:C2:0B:0E ServicesResolved: yes
 [CHG] Device E4:17:D8:C2:0B:0E Paired: yes
 Pairing successful
 
 [bluetooth]# connect E4:17:D8:C2:0B:0E
 Attempting to connect to E4:17:D8:C2:0B:0E
 Failed to connect: org.bluez.Error.Failed
 [CHG] Device E4:17:D8:C2:0B:0E Connected: yes
 Authorize service (yes/no): yes 
 
 Authorize service 00001124-0000-1000-8000-00805f9b34fb 
 [8BitDo M30 Modkit]# trust E4:17:D8:C2:0B:0E
 [CHG] Device E4:17:D8:C2:0B:0E Trusted: yes
 Changing E4:17:D8:C2:0B:0E trust succeeded

Type devices to see a list of devices configurated in your BT setup.
Type remove MAC-ADRESS to remove single devices
Type yes if you are asked for authorization progress or enter PIN

If you have multiple Bluetooth adapters on your machine and you want to tell which one is used, you can use the command hcitool dev to list them all. On my setup, hci0 is the internal BT on my Pi4, and hci1 is an additional USB BT module:

 # hcitool dev
 Devices:
     hci1    90:80:62:00:88:00
     hci0    DC:A6:32:04:10:7F
  
 # bluetoothctl 
 Agent registered
 [bluetooth]# scan on
 Discovery started
 [CHG] Controller 90:80:62:00:88:00 Discovering: yes

Some devices out there break Bluetooth protocol and are always in “pairing” mode, common with modern “smart” TVs. Since Batocera will automatically connect to any device in pair mode, this could cause unintended connections.

To work around this, it is possible to pair to only strictly pads. Put your controller into its pairing mode and then run the following:

batocera-bluetooth trust-pad

Batocera will explicitly only search for and connect to Bluetooth controllers. This may take a while as it methodically goes through, parses and accepts/rejects devices in the background. Once the pad is found, Batocera will attempt to pair to it:

[root@RPI3-BATOCERA /userdata/system]# batocera-bluetooth trust-pad
Pairing 8BitDo M30 gamepad...
Trusting 8BitDo M30 gamepad...
[root@RPI3-BATOCERA /userdata/system]#

The Bluetooth controller can now be used with Batocera.

Conversely, the same can be done to connect strictly to audio devices:

batocera-bluetooth trust-audio

Blacklisting a device in Batocera v33

The functionality of this has been supplanted by trust-pad method described above. These instructions are retained here specifically for Batocera v33 and no other version.

There might be some device that is perpetually in pairing mode that you don't want your Batocera machine to connect to (such as your neighbor's “smart” TV). You can block such devices by utilizing the blacklist.

In order to do this via SSH, run the following command:

batocera-bluetooth blacklist <device address> <device name>

For example:

To show a list of all the currently blacklisted devices:

batocera-bluetooth list_blacklistable

To remove a device from the blacklist:

batocera-bluetooth unblacklist <device address>

batocera-bluetooth list                          Print the list of currently trusted and saved Bluetooth devices.
batocera-bluetooth trust                         Scan for and trust a new, randomly(?) selected device. Good luck!
batocera-bluetooth trust-pad                     Scan for and trust only controllers.
batocera-bluetooth trust-audio                   Scan for and trust only audio devices.
batocera-bluetooth starttrust
batocera-bluetooth stoptrust
batocera-bluetooth remove <device address>       Removes (untrusts) specified Bluetooth device from the list and removes its connection from memory.
batocera-bluetooth save                          Saves the newly trusted device to memory.
batocera-bluetooth restore                       Undoes any trusted but not currently saved device and restores from memory.
batocera-bluetooth live_devices                  Lists all current nearby devices in pairing mode.

v33 specific commands

batocera-bluetooth list_blacklistable            Print the list of currently blacklisted Bluetooth devices.
batocera-bluetooth blacklist <device address> <device name>  Adds a device to the blacklist, preventing it from being paired to.
batocera-bluetooth unblacklist <device address>  Removes specified Bluetooth device from the blacklist.