I purchased the Samsung Trio 500, a Bluetooth keyboard with many reviews for its high quality.

Connected well to my Mac and also to my V30 Android phone. Today, I tried connecting to Xps13 that Xubuntu installed on. I used a GUI app, blueman-manager, to connect and use any Bluetooth device. But for some reason, the Trio 500 kept not pairing. But now that I'm writing this article using that keyboard, can you tell that I've succeeded?

Trio 500 requires a PIN code to be paired. During the pairing process, a pop-up will appear on the screen asking you to enter a six-digit number. Then, input the number on the keyboard and press Enter to complete the final pairing. But strangely, no such popup or message was shown on my Linux. When I tried to connect another Bluetooth keyboard in the past, such a message appeared in blueman as well. And the pairing went well. But why is this keyboard not getting such a message and just a message stating that pairing has failed?

Eventually, I found a tool called

bluetoothctl

through Googling. bluetoothctl is a CLI command that supports REPL (interactive).

If you input the corresponding command first, it enters the REPL mode.

$ bluetoothctl 
Agent registered
[AnnePro2 P1]# 

I was using the AnnePro2 keyboard connected via Bluetooth at the time, so the prompt was displayed like that. This prompt will probably be different depending on your situation.

Here, if you first run the command help, a list of supported commands is displayed. If you enter the command paired-devices, a list of currently paired devices is displayed.

First, you need to know the address of the device. In fact, even blueman can 'scan' it. Therefore, the address itself can be found there as well. But you can also scan from bluetoothctl. Enter the command scan on in interactive mode.

[AnnePro2 P1]# scan on
Discovery started
[CHG] Controller XX:XX:XX:XX:XX:XX Discovering: yes
[CHG] Device XX:XX:XX:XX:XX:XX RSSI: -54
[CHG] Device XX:XX:XX:XX:XX:XX Appearance: 0x03c1

While scan mode is on, each time a new device is scanned, that information is continuously displayed on the screen as above.

The Trio 500 was also displayed on the screen, but you can't tell which one is the Trio 500 just by looking at it. You might get some hints by looking at the Icon: input-keyboard message. Alternatively, it can be inferred by looking at the message displayed on the screen when the keyboard enters pairing mode after turning the power off and on.

For reference, you have to press the Bluetooth button on the Trio 500 for about 3 seconds to enter pairing mode. In pairing mode, the LED blinks quickly to indicate the status.

Copy the device address you found. And first, turn off scan mode.

 [AnnePro2 P1]# scan off

For actual pairing, use the pair command. After pair, enter the address of the Trio 500 found above. Then, a 6-digit numeric value (pin code) to be entered is displayed on the screen, such as PassKey 123456. If you type this on the keyboard and hit enter, the pairing is finally completed.

[AnnePro2 P1]# pair XX:XX:XX:XX:XX:XX
Attempting to pair with XX:XX:XX:XX:XX:XX
[CHG] Device XX:XX:XX:XX:XX:XX Connected: yes
[agent] Passkey: 123456
[CHG] Device XX:XX:XX:XX:XX:XX Paired: yes
Pairing successful

Korean : 삼성 블루투스 키보드 트리오 500 Xubuntu에서 페어링