Ubuntu 20.04 cannot pair Bluetooth Keyboard

Question

Dell Vostro 2520
Broadcom Corp. BCM43142 Bluetooth 4.0
Ubuntu 20.04
Windows 10 Pro
Windows 10 Home
Android 11
iPhone 12

I purchased a mini Bluetooth keyboard for use with my Android phone. Brand unknown but the model number is BK3001; there are hundreds available on eBay, Amazon, etc. This keyboard works with Android 11 on my Xiaomi Redmi Note 9 Pro smartphone, Windows 10 Pro* and Home+, and iPhone. But when on Ubuntu 20.04.x I open the Settings app at Bluetooth and it scans for Bluetooth devices forever without noticing my keyboard, imaginatively named "Bluetooth Keyboard".

After searching AskUbuntu again I tried:

~$ bluetoothctl  
Agent registered  
[bluetooth]# power on  
Changing power on succeeded  
[bluetooth]# agent on  
Agent is already registered  
[bluetooth]# default-agent  
Default agent request successful  
[bluetooth]# scan on  
Discovery started  
[bluetooth]#

Again discovery finds nothing. Neither does:

~$ hcitool scan  
Scanning ...  

~$ bt-device -l

No devices found

Shouldn't Bluetooth Just Work? It has been around for quite a while now but although many other devices can find it, Ubuntu 20.04 can't. Any advice please?

* My wife's Lenovo laptop.
+ Dual-booted into Dell Vostro 2520.

Probably a silly question, but have you confirmed that the keyboard is not already connected to another device when you are having Ubuntu look for it? Associated devices will (usually) not broadcast their existence if already connected to something. — matigo, Mar 18 '22 at 04:08
Pretty sure the keyboard was disconnected from my smartphone at the time. How would you explain Ubuntu 20.04's inability to find any other Bluetooth devices? — Hedley Finger, Mar 18 '22 at 09:42
please edit the question to include results from terminal for lsusb; sudo dmesg | egrep -i 'blue|firm' — Jeremy31, Mar 20 '22 at 10:47

score 3 · Answer 1 · answered Apr 25 '24 at 08:03

3

Check your /etc/bluetooth/main.conf file if ControllerMode is set to bredr. It should be set to dual (or comment out that line as that is the default value). Then you should be able to pair the keyboard. It will ask you to type a six digit pin code and press Enter.

answered Apr 25 '24 at 08:03

Nighto

131

1

This worked for me, after the changes, just restart the bluetooth and try again. – Ivan-San Jan 21 '25 at 22:06
I was about to send the keyboard back. Thanks :) – Hamid Haghdoost Feb 03 '25 at 14:37

score 2 · Answer 2 · answered Mar 25 '23 at 16:31

2

I saw this video and it solved my issue. When I tried to pair the device, the pairing required a passcode to be typed in, but the bluetooth GUI doesn't show you the passcode to type in to finish the pairing.

I had to pair the bluetooth devices via command line, as the command line will show you the passcode that needs to be typed in to complete the pairing process.

https://youtu.be/FomPUvv0tSw

answered Mar 25 '23 at 16:31

orion_pax

21

Keyboards do not usually need a code. Are you sure your answer is for a keyboard? – David DE Mar 25 '23 at 17:29
1

@David Wrong, a Bluetooth keyboard can ask you for that. I had quite a few Bluetooth keyboards that asked for it. – questionto42 Dec 13 '23 at 22:40
I clearly said usually not a wrong comment. – David DE Jan 23 '24 at 12:34

Hedley Finger · Answer 3 · 2022-03-20T07:01:58.300

It appears that if the Dell Vostro 2025 is suspended and then awakened later, Bluetooth cannot detect any external Bluetooth devices. So here is how to get the Bluetooth Keyboard BK3001 to pair with Ubuntu 20.04.4 LTS:

In the device previously paired with Bluetooth Keyboard, unpair the keyboard and switch it off.
If a record of the Bluetooth keyboard has been saved in the previous device, delete the record.
Switch off (Power Off) your computer completely (no restart).
Switch your computer on and make sure Bluetooth is switched off. You may have to do this in the in the menu that drops down from the RH end of the screen title bar and by opening Settings > Bluetooth and setting the toggle switch to off.*
Now turn over the Bluetooth Keyboard, switch it on, and press the small black activation button. The faint blue pulsing on the upper right of the top of the keyboard indicates pairing is being attempted.
Back at Ubuntu, switch Settings > Bluetooth on.* You should see a list of detected external devices; be patient as the keyboard may take a little while to display the pairing code.
When the pairing code appears, type the string of digits and press the Enter key (easy to overlook). Voilá, Ubuntu and keyboard are paired!

* The title-bar menu and Settings > Bluetooth may not synchronise. I have seen one show that Bluetooth is on and the other that it is off. Awakening from sleep also needs to be fixed so that Bluetooth returns to the state is was in before suspension.

Ubuntu 20.04 cannot pair Bluetooth Keyboard

3 Answers3